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RK3288-FireFly no HDMI Sound #30

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sghazagh opened this issue Aug 11, 2017 · 14 comments
Open

RK3288-FireFly no HDMI Sound #30

sghazagh opened this issue Aug 11, 2017 · 14 comments

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@sghazagh
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Hi,
I just have used this repository to update my kernel and device tree for rk3288-Firefly.
The only available Sound system is SPDIF and we have no sound on HDMI to select.

When I use KODI I only have to connect SPDIF and the sound is not available on HDMI.
Can you please provide a patch and fix for having HDMI sound as an alternative option to SPDIF for sound system.

Thanks

@sghazagh
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Seriously? no one even bother to reply?!!!!!

@geekerlw
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you need enable sound support for hdmi, just do like this: geekerlw@5d50103 , not complete

@sghazagh
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hi,
thanks for reply.
I tried to adjust the dtsi you have provided.

  • if I only add sounds section to existing rk3288-firefly.dtsi, the board does not boot at all.
  • if I use completely the dtsi you gave the link, I have to remove the "io-domain" section as it said it is duplicated.
    in that way, I could load the board but had some issue
    = first of all, the HDMI sound wasn't available again
    = the wifi went off. Even when I enable the "rkwifi section (line 266-269) which is commented by default, it does not detect the wifi anymore.
    = the HDMI resolution drops to 1280x820 from 1920x1080

I think the patch is for Analog Audio and not HDMI!

Have you got audio on HDMI?
What if I compile the whole kernel you addressed above?
Does that work?

@geekerlw
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The whole kernel under my github is working both earphone and hdmi, the commit above also change wifi or bluetooth, I forget, see another commit geekerlw@17c71f7 , the two commit maybe complete. Anyway, just make sure dts have current sound node, do not use my dts, I disabled rkwifi system:)

@sghazagh
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Unfortunately I don't have enough knowledge to manipulate Device Trees. I only can adjust simple changes.
Is it possible you help me write a proper part which needs to have HDMI sound?
Here is the DTS file I need to get fixed:
https://github.com/rockchip-linux/kernel/blob/release-4.4/arch/arm/boot/dts/rk3288-firefly.dtsi

If you fix that,I think everyone using official rockchip-linux kernel repository will get the benefit....
Hope you can have some spare time to help... !?!?!?

@sghazagh
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sghazagh commented Aug 17, 2017

I tried to only add the changes on these two commits into the dtsi file which I mentioned the link in my last post.
The system cannot boot at all!!!

By the way, other than these changes, do I need to enable anything in Kernel itself?
"Rockchip I2S Device Driver" & "Rockchip SPDIF Device Driver" have already been selected but,
"Rockchip PDM control driver" is not selected by default!

and also both:
"ASoC support for Rockchip built-in HDMI and CODEC IC"
and
"ASoC support for Rockchip built-in HDMI and DP" haven't been selected.
Does those make some difference?

@sghazagh
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I just found that there is reference to i2c5 which was not exist in my dtsi.
Have added that and I could boot the machine.
However, the resolution was to big! 1356x2048 !!!
I just made it window by chance to see what is going on and Audio still didn't have the HDMI option!!!

I think I have to give up if no one helps :(

@geekerlw
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geekerlw commented Aug 17, 2017 via email

@elar-systems
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What do you need, I can post whatever can help.
As I mentioned, I use:

  • linux-rockchip kernel, compiled as default defconfig from this repository
  • OS is default rk-build-rootfs provided by rockchip wiki guide uses linaro base Debian Stretch
  • KODI 17.3 provided by user mac-l1 in Firefly Forum.

What I have done:

  • Used the default rk3288-firefly.dtsi file, in that case all good except no HDMI audio.
  • I used the same file, manually patched the file with above two commits you mentioned above.
    Then the board boots but screen scales too big by default. No HDMI listed in Audio sources
  • To test if all setting all fine, I have used kernel and DTB was in image provided with user mac-l1 for kodi 17.3. That kernel and DTB works just fine and HDMI also is available.

The issue is that, I have no source for the working one and I don't know from where that guys compiled and imncluded the DTB file inside his image. So if I want any change in Device tree (LED for instance), or kernel feature, then I have no option.
Thats why I need a working kernel and dtb with access to source.

Another explanation, I am using KODi starts from command. So I installed "xserver-xorg-legacy" to be able to run it from command. I disabled display-manager service to directly get into KODi.

As I mentioned all good with that guys kernel and DTB so there is nothing wrong with settings.
I only do not have proper compiled kernel and device tree of mine!

@geekerlw
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I want to see your boot log, you can send to me a persional email, maybe you can try my kernel, I'll put it in the reply email:)

@sghazagh
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You mean "dmesg" for boot log, right? Ok, I will send you ...
(I also sent an email right now to have my email address)

I would like to test your Kernel, but you said don't use the dtsi file as you have customized it for your use!

Many thanks for your help...

@sghazagh
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Author

@geekerlw,
I double checked the difference of your kernel and the one in here.
I adjusted the DTS file and this time the sound got worked and I hade audio on HDMI.
However, if I use the new compiled one which I adjusted, the only resolution will be 1536x2048 therefore that does not fit to my screen and oversize.

Have you any idea why the resolution changes unexpectedly?
I search through "rk3288-firefly.dtsi" file and there is nothing hard-coded for display resolution.
Do you know why the HDMI resolution changes when we apply your sound changes to the 4.4.77 kernel DTSI file?

Anyone else have any idea how we can fix the display resolution issue (on KODI 17.3 I'm talking)!!!

@geekerlw
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I don't know why. My release branch is 2066 commits behind rockchip-linux:release-4.4, I don't have enouth time to upgrade to the newest kernel.

@sghazagh
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So, then please someone try to patch this kernel to have sound on HDMI...

rkchrome pushed a commit that referenced this issue Jul 19, 2018
[ Upstream commit a8d7aa1 ]

syzbot reported a crash in tasklet_action_common() caused by dccp.

dccp needs to make sure socket wont disappear before tasklet handler
has completed.

This patch takes a reference on the socket when arming the tasklet,
and moves the sock_put() from dccp_write_xmit_timer() to dccp_write_xmitlet()

kernel BUG at kernel/softirq.c:514!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 17 Comm: ksoftirqd/1 Not tainted 4.17.0-rc3+ #30
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:tasklet_action_common.isra.19+0x6db/0x700 kernel/softirq.c:515
RSP: 0018:ffff8801d9b3faf8 EFLAGS: 00010246
dccp_close: ABORT with 65423 bytes unread
RAX: 1ffff1003b367f6b RBX: ffff8801daf1f3f0 RCX: 0000000000000000
RDX: ffff8801cf895498 RSI: 0000000000000004 RDI: 0000000000000000
RBP: ffff8801d9b3fc40 R08: ffffed0039f12a95 R09: ffffed0039f12a94
dccp_close: ABORT with 65423 bytes unread
R10: ffffed0039f12a94 R11: ffff8801cf8954a3 R12: 0000000000000000
R13: ffff8801d9b3fc18 R14: dffffc0000000000 R15: ffff8801cf895490
FS:  0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2bc28000 CR3: 00000001a08a9000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 tasklet_action+0x1d/0x20 kernel/softirq.c:533
 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:285
dccp_close: ABORT with 65423 bytes unread
 run_ksoftirqd+0x86/0x100 kernel/softirq.c:646
 smpboot_thread_fn+0x417/0x870 kernel/smpboot.c:164
 kthread+0x345/0x410 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412
Code: 48 8b 85 e8 fe ff ff 48 8b 95 f0 fe ff ff e9 94 fb ff ff 48 89 95 f0 fe ff ff e8 81 53 6e 00 48 8b 95 f0 fe ff ff e9 62 fb ff ff <0f> 0b 48 89 cf 48 89 8d e8 fe ff ff e8 64 53 6e 00 48 8b 8d e8
RIP: tasklet_action_common.isra.19+0x6db/0x700 kernel/softirq.c:515 RSP: ffff8801d9b3faf8

Fixes: dc841e3 ("dccp: Extend CCID packet dequeueing interface")
Signed-off-by: Eric Dumazet <[email protected]>
Reported-by: syzbot <[email protected]>
Cc: Gerrit Renker <[email protected]>
Cc: [email protected]
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
rkchrome pushed a commit that referenced this issue Sep 12, 2018
[ Upstream commit 6d37fa4 ]

In l2tp code, if it is a L2TP_UDP_ENCAP tunnel, tunnel->sk points to a
UDP socket. User could call sendmsg() on both this tunnel and the UDP
socket itself concurrently. As l2tp_xmit_skb() holds socket lock and call
__sk_dst_check() to refresh sk->sk_dst_cache, while udpv6_sendmsg() is
lockless and call sk_dst_check() to refresh sk->sk_dst_cache, there
could be a race and cause the dst cache to be freed multiple times.
So we fix l2tp side code to always call sk_dst_check() to garantee
xchg() is called when refreshing sk->sk_dst_cache to avoid race
conditions.

Syzkaller reported stack trace:
BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
BUG: KASAN: use-after-free in atomic_fetch_add_unless include/linux/atomic.h:575 [inline]
BUG: KASAN: use-after-free in atomic_add_unless include/linux/atomic.h:597 [inline]
BUG: KASAN: use-after-free in dst_hold_safe include/net/dst.h:308 [inline]
BUG: KASAN: use-after-free in ip6_hold_safe+0xe6/0x670 net/ipv6/route.c:1029
Read of size 4 at addr ffff8801aea9a880 by task syz-executor129/4829

CPU: 0 PID: 4829 Comm: syz-executor129 Not tainted 4.18.0-rc7-next-20180802+ #30
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272
 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
 atomic_fetch_add_unless include/linux/atomic.h:575 [inline]
 atomic_add_unless include/linux/atomic.h:597 [inline]
 dst_hold_safe include/net/dst.h:308 [inline]
 ip6_hold_safe+0xe6/0x670 net/ipv6/route.c:1029
 rt6_get_pcpu_route net/ipv6/route.c:1249 [inline]
 ip6_pol_route+0x354/0xd20 net/ipv6/route.c:1922
 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2098
 fib6_rule_lookup+0x283/0x890 net/ipv6/fib6_rules.c:122
 ip6_route_output_flags+0x2c5/0x350 net/ipv6/route.c:2126
 ip6_dst_lookup_tail+0x1278/0x1da0 net/ipv6/ip6_output.c:978
 ip6_dst_lookup_flow+0xc8/0x270 net/ipv6/ip6_output.c:1079
 ip6_sk_dst_lookup_flow+0x5ed/0xc50 net/ipv6/ip6_output.c:1117
 udpv6_sendmsg+0x2163/0x36b0 net/ipv6/udp.c:1354
 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:632
 ___sys_sendmsg+0x51d/0x930 net/socket.c:2115
 __sys_sendmmsg+0x240/0x6f0 net/socket.c:2210
 __do_sys_sendmmsg net/socket.c:2239 [inline]
 __se_sys_sendmmsg net/socket.c:2236 [inline]
 __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2236
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x446a29
Code: e8 ac b8 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f4de5532db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000006dcc38 RCX: 0000000000446a29
RDX: 00000000000000b8 RSI: 0000000020001b00 RDI: 0000000000000003
RBP: 00000000006dcc30 R08: 00007f4de5533700 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc3c
R13: 00007ffe2b830fdf R14: 00007f4de55339c0 R15: 0000000000000001

Fixes: 71b1391 ("l2tp: ensure sk->dst is still valid")
Reported-by: [email protected]
Signed-off-by: Wei Wang <[email protected]>
Signed-off-by: Martin KaFai Lau <[email protected]>
Cc: Guillaume Nault <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Cong Wang <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
rkchrome pushed a commit that referenced this issue Sep 26, 2018
[ Upstream commit a8d7aa1 ]

syzbot reported a crash in tasklet_action_common() caused by dccp.

dccp needs to make sure socket wont disappear before tasklet handler
has completed.

This patch takes a reference on the socket when arming the tasklet,
and moves the sock_put() from dccp_write_xmit_timer() to dccp_write_xmitlet()

kernel BUG at kernel/softirq.c:514!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 17 Comm: ksoftirqd/1 Not tainted 4.17.0-rc3+ #30
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:tasklet_action_common.isra.19+0x6db/0x700 kernel/softirq.c:515
RSP: 0018:ffff8801d9b3faf8 EFLAGS: 00010246
dccp_close: ABORT with 65423 bytes unread
RAX: 1ffff1003b367f6b RBX: ffff8801daf1f3f0 RCX: 0000000000000000
RDX: ffff8801cf895498 RSI: 0000000000000004 RDI: 0000000000000000
RBP: ffff8801d9b3fc40 R08: ffffed0039f12a95 R09: ffffed0039f12a94
dccp_close: ABORT with 65423 bytes unread
R10: ffffed0039f12a94 R11: ffff8801cf8954a3 R12: 0000000000000000
R13: ffff8801d9b3fc18 R14: dffffc0000000000 R15: ffff8801cf895490
FS:  0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2bc28000 CR3: 00000001a08a9000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 tasklet_action+0x1d/0x20 kernel/softirq.c:533
 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:285
dccp_close: ABORT with 65423 bytes unread
 run_ksoftirqd+0x86/0x100 kernel/softirq.c:646
 smpboot_thread_fn+0x417/0x870 kernel/smpboot.c:164
 kthread+0x345/0x410 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412
Code: 48 8b 85 e8 fe ff ff 48 8b 95 f0 fe ff ff e9 94 fb ff ff 48 89 95 f0 fe ff ff e8 81 53 6e 00 48 8b 95 f0 fe ff ff e9 62 fb ff ff <0f> 0b 48 89 cf 48 89 8d e8 fe ff ff e8 64 53 6e 00 48 8b 8d e8
RIP: tasklet_action_common.isra.19+0x6db/0x700 kernel/softirq.c:515 RSP: ffff8801d9b3faf8

Fixes: dc841e3 ("dccp: Extend CCID packet dequeueing interface")
Signed-off-by: Eric Dumazet <[email protected]>
Reported-by: syzbot <[email protected]>
Cc: Gerrit Renker <[email protected]>
Cc: [email protected]
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
rkchrome pushed a commit that referenced this issue Sep 26, 2018
[ Upstream commit 6d37fa4 ]

In l2tp code, if it is a L2TP_UDP_ENCAP tunnel, tunnel->sk points to a
UDP socket. User could call sendmsg() on both this tunnel and the UDP
socket itself concurrently. As l2tp_xmit_skb() holds socket lock and call
__sk_dst_check() to refresh sk->sk_dst_cache, while udpv6_sendmsg() is
lockless and call sk_dst_check() to refresh sk->sk_dst_cache, there
could be a race and cause the dst cache to be freed multiple times.
So we fix l2tp side code to always call sk_dst_check() to garantee
xchg() is called when refreshing sk->sk_dst_cache to avoid race
conditions.

Syzkaller reported stack trace:
BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
BUG: KASAN: use-after-free in atomic_fetch_add_unless include/linux/atomic.h:575 [inline]
BUG: KASAN: use-after-free in atomic_add_unless include/linux/atomic.h:597 [inline]
BUG: KASAN: use-after-free in dst_hold_safe include/net/dst.h:308 [inline]
BUG: KASAN: use-after-free in ip6_hold_safe+0xe6/0x670 net/ipv6/route.c:1029
Read of size 4 at addr ffff8801aea9a880 by task syz-executor129/4829

CPU: 0 PID: 4829 Comm: syz-executor129 Not tainted 4.18.0-rc7-next-20180802+ #30
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272
 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
 atomic_fetch_add_unless include/linux/atomic.h:575 [inline]
 atomic_add_unless include/linux/atomic.h:597 [inline]
 dst_hold_safe include/net/dst.h:308 [inline]
 ip6_hold_safe+0xe6/0x670 net/ipv6/route.c:1029
 rt6_get_pcpu_route net/ipv6/route.c:1249 [inline]
 ip6_pol_route+0x354/0xd20 net/ipv6/route.c:1922
 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2098
 fib6_rule_lookup+0x283/0x890 net/ipv6/fib6_rules.c:122
 ip6_route_output_flags+0x2c5/0x350 net/ipv6/route.c:2126
 ip6_dst_lookup_tail+0x1278/0x1da0 net/ipv6/ip6_output.c:978
 ip6_dst_lookup_flow+0xc8/0x270 net/ipv6/ip6_output.c:1079
 ip6_sk_dst_lookup_flow+0x5ed/0xc50 net/ipv6/ip6_output.c:1117
 udpv6_sendmsg+0x2163/0x36b0 net/ipv6/udp.c:1354
 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:632
 ___sys_sendmsg+0x51d/0x930 net/socket.c:2115
 __sys_sendmmsg+0x240/0x6f0 net/socket.c:2210
 __do_sys_sendmmsg net/socket.c:2239 [inline]
 __se_sys_sendmmsg net/socket.c:2236 [inline]
 __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2236
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x446a29
Code: e8 ac b8 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f4de5532db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000006dcc38 RCX: 0000000000446a29
RDX: 00000000000000b8 RSI: 0000000020001b00 RDI: 0000000000000003
RBP: 00000000006dcc30 R08: 00007f4de5533700 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc3c
R13: 00007ffe2b830fdf R14: 00007f4de55339c0 R15: 0000000000000001

Fixes: 71b1391 ("l2tp: ensure sk->dst is still valid")
Reported-by: [email protected]
Signed-off-by: Wei Wang <[email protected]>
Signed-off-by: Martin KaFai Lau <[email protected]>
Cc: Guillaume Nault <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Cong Wang <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
0lvin pushed a commit to free-z4u/roc-rk3328-cc-official that referenced this issue Jun 21, 2019
With >=32 CPUs the userfaultfd selftest triggered a graceful but
unexpected SIGBUS because VM_FAULT_RETRY was returned by
handle_userfault() despite the UFFDIO_COPY wasn't completed.

This seems caused by rwsem waking the thread blocked in
handle_userfault() and we can't run up_read() before the wait_event
sequence is complete.

Keeping the wait_even sequence identical to the first one, would require
running userfaultfd_must_wait() again to know if the loop should be
repeated, and it would also require retaking the rwsem and revalidating
the whole vma status.

It seems simpler to wait the targeted wakeup so that if false wakeups
materialize we still wait for our specific wakeup event, unless of
course there are signals or the uffd was released.

Debug code collecting the stack trace of the wakeup showed this:

  $ ./userfaultfd 100 99999
  nr_pages: 25600, nr_pages_per_cpu: 800
  bounces: 99998, mode: racing ver poll, userfaults: 32 35 90 232 30 138 69 82 34 30 139 40 40 31 20 19 43 13 15 28 27 38 21 43 56 22 1 17 31 8 4 2
  bounces: 99997, mode: rnd ver poll, Bus error (core dumped)

    save_stack_trace+0x2b/0x50
    try_to_wake_up+0x2a6/0x580
    wake_up_q+0x32/0x70
    rwsem_wake+0xe0/0x120
    call_rwsem_wake+0x1b/0x30
    up_write+0x3b/0x40
    vm_mmap_pgoff+0x9c/0xc0
    SyS_mmap_pgoff+0x1a9/0x240
    SyS_mmap+0x22/0x30
    entry_SYSCALL_64_fastpath+0x1f/0xbd
    0xffffffffffffffff
    FAULT_FLAG_ALLOW_RETRY missing 70
  CPU: 24 PID: 1054 Comm: userfaultfd Tainted: G        W       4.8.0+ rockchip-linux#30
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
  Call Trace:
    dump_stack+0xb8/0x112
    handle_userfault+0x572/0x650
    handle_mm_fault+0x12cb/0x1520
    __do_page_fault+0x175/0x500
    trace_do_page_fault+0x61/0x270
    do_async_page_fault+0x19/0x90
    async_page_fault+0x25/0x30

This always happens when the main userfault selftest thread is running
clone() while glibc runs either mprotect or mmap (both taking mmap_sem
down_write()) to allocate the thread stack of the background threads,
while locking/userfault threads already run at full throttle and are
susceptible to false wakeups that may cause handle_userfault() to return
before than expected (which results in graceful SIGBUS at the next
attempt).

This was reproduced only with >=32 CPUs because the loop to start the
thread where clone() is too quick with fewer CPUs, while with 32 CPUs
there's already significant activity on ~32 locking and userfault
threads when the last background threads are started with clone().

This >=32 CPUs SMP race condition is likely reproducible only with the
selftest because of the much heavier userfault load it generates if
compared to real apps.

We'll have to allow "one more" VM_FAULT_RETRY for the WP support and a
patch floating around that provides it also hidden this problem but in
reality only is successfully at hiding the problem.

False wakeups could still happen again the second time
handle_userfault() is invoked, even if it's a so rare race condition
that getting false wakeups twice in a row is impossible to reproduce.
This full fix is needed for correctness, the only alternative would be
to allow VM_FAULT_RETRY to be returned infinitely.  With this fix the WP
support can stick to a strict "one more" VM_FAULT_RETRY logic (no need
of returning it infinite times to avoid the SIGBUS).

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Andrea Arcangeli <[email protected]>
Reported-by: Shubham Kumar Sharma <[email protected]>
Tested-by: Mike Kravetz <[email protected]>
Acked-by: Hillf Danton <[email protected]>
Cc: Michael Rapoport <[email protected]>
Cc: "Dr. David Alan Gilbert" <[email protected]>
Cc: Pavel Emelyanov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
0lvin pushed a commit to free-z4u/roc-rk3328-cc-official that referenced this issue Jun 21, 2019
Since commit 5d47ec0 ("firmware: Correct handling of
fw_state_wait() return value") fw_load_abort() could be called twice and
lead us to a kernel crash. This happens only when the firmware fallback
mechanism (regular or custom) is used. The fallback mechanism exposes a
sysfs interface for userspace to upload a file and notify the kernel
when the file is loaded and ready, or to cancel an upload by echo'ing -1
into on the loading file:

echo -n "-1" > /sys/$DEVPATH/loading

This will call fw_load_abort(). Some distributions actually have a udev
rule in place to *always* immediately cancel all firmware fallback
mechanism requests (Debian), they have:

  $ cat /lib/udev/rules.d/50-firmware.rules
  # stub for immediately telling the kernel that userspace firmware loading
  # failed; necessary to avoid long timeouts with CONFIG_FW_LOADER_USER_HELPER=y
  SUBSYSTEM=="firmware", ACTION=="add", ATTR{loading}="-1

Distributions with this udev rule would run into this crash only if the
fallback mechanism is used. Since most distributions disable by default
using the fallback mechanism (CONFIG_FW_LOADER_USER_HELPER_FALLBACK),
this would typicaly mean only 2 drivers which *require* the fallback
mechanism could typically incur a crash: drivers/firmware/dell_rbu.c and
the drivers/leds/leds-lp55xx-common.c driver. Distributions enabling
CONFIG_FW_LOADER_USER_HELPER_FALLBACK by default are obviously more
exposed to this crash.

The crash happens because after commit 5b02962 ("firmware: do not
use fw_lock for fw_state protection") and subsequent fix commit
5d47ec0 ("firmware: Correct handling of fw_state_wait() return
value") a race can happen between this cancelation and the firmware
fw_state_wait_timeout() being woken up after a state change with which
fw_load_abort() as that calls swake_up(). Upon error
fw_state_wait_timeout() will also again call fw_load_abort() and trigger
a null reference.

At first glance we could just fix this with a !buf check on
fw_load_abort() before accessing buf->fw_st, however there is a logical
issue in having a state machine used for the fallback mechanism and
preventing access from it once we abort as its inside the buf
(buf->fw_st).

The firmware_class.c code is setting the buf to NULL to annotate an
abort has occurred. Replace this mechanism by simply using the state
check instead. All the other code in place already uses similar checks
for aborting as well so no further changes are needed.

An oops can be reproduced with the new fw_fallback.sh fallback mechanism
cancellation test. Either cancelling the fallback mechanism or the
custom fallback mechanism triggers a crash.

mcgrof@piggy ~/linux-next/tools/testing/selftests/firmware
(git::20170111-fw-fixes)$ sudo ./fw_fallback.sh

./fw_fallback.sh: timeout works
./fw_fallback.sh: firmware comparison works
./fw_fallback.sh: fallback mechanism works

[ this then sits here when it is trying the cancellation test ]

Kernel log:

test_firmware: loading 'nope-test-firmware.bin'
misc test_firmware: Direct firmware load for nope-test-firmware.bin failed with error -2
misc test_firmware: Falling back to user helper
BUG: unable to handle kernel NULL pointer dereference at 0000000000000038
IP: _request_firmware+0xa27/0xad0
PGD 0

Oops: 0000 [FireflyTeam#1] SMP
Modules linked in: test_firmware(E) ... etc ...
CPU: 1 PID: 1396 Comm: fw_fallback.sh Tainted: G        W E   4.10.0-rc3-next-20170111+ rockchip-linux#30
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.1-0-g8891697-prebuilt.qemu-project.org 04/01/2014
task: ffff9740b27f4340 task.stack: ffffbb15c0bc8000
RIP: 0010:_request_firmware+0xa27/0xad0
RSP: 0018:ffffbb15c0bcbd10 EFLAGS: 00010246
RAX: 00000000fffffffe RBX: ffff9740afe5aa80 RCX: 0000000000000000
RDX: ffff9740b27f4340 RSI: 0000000000000283 RDI: 0000000000000000
RBP: ffffbb15c0bcbd90 R08: ffffbb15c0bcbcd8 R09: 0000000000000000
R10: 0000000894a0d4b1 R11: 000000000000008c R12: ffffffffc0312480
R13: 0000000000000005 R14: ffff9740b1c32400 R15: 00000000000003e8
FS:  00007f8604422700(0000) GS:ffff9740bfc80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000038 CR3: 000000012164c000 CR4: 00000000000006e0
Call Trace:
 request_firmware+0x37/0x50
 trigger_request_store+0x79/0xd0 [test_firmware]
 dev_attr_store+0x18/0x30
 sysfs_kf_write+0x37/0x40
 kernfs_fop_write+0x110/0x1a0
 __vfs_write+0x37/0x160
 ? _cond_resched+0x1a/0x50
 vfs_write+0xb5/0x1a0
 SyS_write+0x55/0xc0
 ? trace_do_page_fault+0x37/0xd0
 entry_SYSCALL_64_fastpath+0x1e/0xad
RIP: 0033:0x7f8603f49620
RSP: 002b:00007fff6287b788 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055c307b110a0 RCX: 00007f8603f49620
RDX: 0000000000000016 RSI: 000055c3084d8a90 RDI: 0000000000000001
RBP: 0000000000000016 R08: 000000000000c0ff R09: 000055c3084d6336
R10: 000055c307b108b0 R11: 0000000000000246 R12: 000055c307b13c80
R13: 000055c3084d6320 R14: 0000000000000000 R15: 00007fff6287b950
Code: 9f 64 84 e8 9c 61 fe ff b8 f4 ff ff ff e9 6b f9 ff
ff 48 c7 c7 40 6b 8d 84 89 45 a8 e8 43 84 18 00 49 8b be 00 03 00 00 8b
45 a8 <83> 7f 38 02 74 08 e8 6e ec ff ff 8b 45 a8 49 c7 86 00 03 00 00
RIP: _request_firmware+0xa27/0xad0 RSP: ffffbb15c0bcbd10
CR2: 0000000000000038
---[ end trace 6d94ac339c133e6f ]---

Fixes: 5d47ec0 ("firmware: Correct handling of fw_state_wait() return value")
Reported-and-Tested-by: Jakub Kicinski <[email protected]>
Reported-and-Tested-by: Patrick Bruenn <[email protected]>
Reported-by: Chris Wilson <[email protected]>
CC: <[email protected]>    [3.10+]
Signed-off-by: Luis R. Rodriguez <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
rkchrome pushed a commit that referenced this issue Jul 22, 2019
…nable()

[ Upstream commit 898bc40 ]

Fix au0828_analog_stream_enable() to check if device is in the right
state first. When unbind happens while bind is in progress, usbdev
pointer could be invalid in au0828_analog_stream_enable() and a call
to usb_ifnum_to_if() will result in the null pointer dereference.

This problem is found with the new media_dev_allocator.sh test.

kernel: [  590.359623] BUG: unable to handle kernel NULL pointer dereference at 00000000000004e8
kernel: [  590.359627] #PF error: [normal kernel read fault]
kernel: [  590.359629] PGD 0 P4D 0
kernel: [  590.359632] Oops: 0000 [#1] SMP PTI
kernel: [  590.359634] CPU: 3 PID: 1458 Comm: v4l_id Not tainted 5.1.0-rc2+ #30
kernel: [  590.359636] Hardware name: Dell Inc. OptiPlex 7 90/0HY9JP, BIOS A18 09/24/2013
kernel: [  590.359641] RIP: 0010:usb_ifnum_to_if+0x6/0x60
kernel: [  590.359643] Code: 5d 41 5e 41 5f 5d c3 48 83 c4
 10 b8 fa ff ff ff 5b 41 5c 41 5d 41 5e 41 5f 5d c3 b8 fa ff ff ff c3 0f 1f 00 6
6 66 66 66 90 55 <48> 8b 97 e8 04 00 00 48 89 e5 48 85 d2 74 41 0f b6 4a 04 84 c
9 74
kernel: [  590.359645] RSP: 0018:ffffad3cc3c1fc00 EFLAGS: 00010246
kernel: [  590.359646] RAX: 0000000000000000 RBX: ffff8ded b1f3c000 RCX: 1f377e4500000000
kernel: [  590.359648] RDX: ffff8dedfa3a6b50 RSI: 00000000 00000000 RDI: 0000000000000000
kernel: [  590.359649] RBP: ffffad3cc3c1fc28 R08: 00000000 8574acc2 R09: ffff8dedfa3a6b50
kernel: [  590.359650] R10: 0000000000000001 R11: 00000000 00000000 R12: 0000000000000000
kernel: [  590.359652] R13: ffff8dedb1f3f0f0 R14: ffffffff adcf7ec0 R15: 0000000000000000
kernel: [  590.359654] FS:  00007f7917198540(0000) GS:ffff 8dee258c0000(0000) knlGS:0000000000000000
kernel: [  590.359655] CS:  0010 DS: 0000 ES: 0000 CR0: 00 00000080050033
kernel: [  590.359657] CR2: 00000000000004e8 CR3: 00000001 a388e002 CR4: 00000000000606e0
kernel: [  590.359658] Call Trace:
kernel: [  590.359664]  ? au0828_analog_stream_enable+0x2c/0x180
kernel: [  590.359666]  au0828_v4l2_open+0xa4/0x110
kernel: [  590.359670]  v4l2_open+0x8b/0x120
kernel: [  590.359674]  chrdev_open+0xa6/0x1c0
kernel: [  590.359676]  ? cdev_put.part.3+0x20/0x20
kernel: [  590.359678]  do_dentry_open+0x1f6/0x360
kernel: [  590.359681]  vfs_open+0x2f/0x40
kernel: [  590.359684]  path_openat+0x299/0xc20
kernel: [  590.359688]  do_filp_open+0x9b/0x110
kernel: [  590.359695]  ? _raw_spin_unlock+0x27/0x40
kernel: [  590.359697]  ? __alloc_fd+0xb2/0x160
kernel: [  590.359700]  do_sys_open+0x1ba/0x260
kernel: [  590.359702]  ? do_sys_open+0x1ba/0x260
kernel: [  590.359712]  __x64_sys_openat+0x20/0x30
kernel: [  590.359715]  do_syscall_64+0x5a/0x120
kernel: [  590.359718]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Signed-off-by: Shuah Khan <[email protected]>
Signed-off-by: Hans Verkuil <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
0lvin pushed a commit to free-z4u/roc-rk3328-cc-official that referenced this issue Jul 26, 2019
smatch says:

  WARNING: please, no spaces at the start of a line
  rockchip-linux#30: FILE: lib/zlib_inflate/inftrees.c:112:
  +    for (min = 1; min < MAXBITS; min++)$

  total: 0 errors, 1 warnings, 8 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

./patches/zlib-inflate-fix-potential-buffer-overflow.patch has style problems, please review.

NOTE: If any of the errors are false positives, please report
      them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
0lvin pushed a commit to free-z4u/roc-rk3328-cc-official that referenced this issue Aug 3, 2019
generic/361 reports below warning, this is because: once, there is
someone entering into critical region of sbi.cp_lock, if write_end_io.
f2fs_stop_checkpoint is invoked from an triggered IRQ, we will encounter
deadlock.

So this patch changes to use spin_{,un}lock_irq{save,restore} to create
critical region without IRQ enabled to avoid potential deadlock.

 irq event stamp: 83391573
 loop: Write error at byte offset 438729728, length 1024.
 hardirqs last  enabled at (83391573): [<c1809752>] restore_all+0xf/0x65
 hardirqs last disabled at (83391572): [<c1809eac>] reschedule_interrupt+0x30/0x3c
 loop: Write error at byte offset 438860288, length 1536.
 softirqs last  enabled at (83389244): [<c180cc4e>] __do_softirq+0x1ae/0x476
 softirqs last disabled at (83389237): [<c101ca7c>] do_softirq_own_stack+0x2c/0x40
 loop: Write error at byte offset 438990848, length 2048.
 ================================
 WARNING: inconsistent lock state
 4.12.0-rc2+ rockchip-linux#30 Tainted: G           O
 --------------------------------
 inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
 xfs_io/7959 [HC1[1]:SC0[0]:HE0:SE1] takes:
  (&(&sbi->cp_lock)->rlock){?.+...}, at: [<f96f96cc>] f2fs_stop_checkpoint+0x1c/0x50 [f2fs]
 {HARDIRQ-ON-W} state was registered at:
   __lock_acquire+0x527/0x7b0
   lock_acquire+0xae/0x220
   _raw_spin_lock+0x42/0x50
   do_checkpoint+0x165/0x9e0 [f2fs]
   write_checkpoint+0x33f/0x740 [f2fs]
   __f2fs_sync_fs+0x92/0x1f0 [f2fs]
   f2fs_sync_fs+0x12/0x20 [f2fs]
   sync_filesystem+0x67/0x80
   generic_shutdown_super+0x27/0x100
   kill_block_super+0x22/0x50
   kill_f2fs_super+0x3a/0x40 [f2fs]
   deactivate_locked_super+0x3d/0x70
   deactivate_super+0x40/0x60
   cleanup_mnt+0x39/0x70
   __cleanup_mnt+0x10/0x20
   task_work_run+0x69/0x80
   exit_to_usermode_loop+0x57/0x85
   do_fast_syscall_32+0x18c/0x1b0
   entry_SYSENTER_32+0x4c/0x7b
 irq event stamp: 1957420
 hardirqs last  enabled at (1957419): [<c1808f37>] _raw_spin_unlock_irq+0x27/0x50
 hardirqs last disabled at (1957420): [<c1809f9c>] call_function_single_interrupt+0x30/0x3c
 softirqs last  enabled at (1953784): [<c180cc4e>] __do_softirq+0x1ae/0x476
 softirqs last disabled at (1953773): [<c101ca7c>] do_softirq_own_stack+0x2c/0x40

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&(&sbi->cp_lock)->rlock);
   <Interrupt>
     lock(&(&sbi->cp_lock)->rlock);

  *** DEADLOCK ***

 2 locks held by xfs_io/7959:
  #0:  (sb_writers#13){.+.+.+}, at: [<c11fd7ca>] vfs_write+0x16a/0x190
  FireflyTeam#1:  (&sb->s_type->i_mutex_key#16){+.+.+.}, at: [<f96e33f5>] f2fs_file_write_iter+0x25/0x140 [f2fs]

 stack backtrace:
 CPU: 2 PID: 7959 Comm: xfs_io Tainted: G           O    4.12.0-rc2+ rockchip-linux#30
 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
 Call Trace:
  dump_stack+0x5f/0x92
  print_usage_bug+0x1d3/0x1dd
  ? check_usage_backwards+0xe0/0xe0
  mark_lock+0x23d/0x280
  __lock_acquire+0x699/0x7b0
  ? __this_cpu_preempt_check+0xf/0x20
  ? trace_hardirqs_off_caller+0x91/0xe0
  lock_acquire+0xae/0x220
  ? f2fs_stop_checkpoint+0x1c/0x50 [f2fs]
  _raw_spin_lock+0x42/0x50
  ? f2fs_stop_checkpoint+0x1c/0x50 [f2fs]
  f2fs_stop_checkpoint+0x1c/0x50 [f2fs]
  f2fs_write_end_io+0x147/0x150 [f2fs]
  bio_endio+0x7a/0x1e0
  blk_update_request+0xad/0x410
  blk_mq_end_request+0x16/0x60
  lo_complete_rq+0x3c/0x70
  __blk_mq_complete_request_remote+0x11/0x20
  flush_smp_call_function_queue+0x6d/0x120
  ? debug_smp_processor_id+0x12/0x20
  generic_smp_call_function_single_interrupt+0x12/0x30
  smp_call_function_single_interrupt+0x25/0x40
  call_function_single_interrupt+0x37/0x3c
 EIP: _raw_spin_unlock_irq+0x2d/0x50
 EFLAGS: 00000296 CPU: 2
 EAX: 00000001 EBX: d2ccc51c ECX: 00000001 EDX: c1aacebd
 ESI: 00000000 EDI: 00000000 EBP: c96c9d1c ESP: c96c9d18
  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
  ? inherit_task_group.isra.98.part.99+0x6b/0xb0
  __add_to_page_cache_locked+0x1d4/0x290
  add_to_page_cache_lru+0x38/0xb0
  pagecache_get_page+0x8e/0x200
  f2fs_write_begin+0x96/0xf00 [f2fs]
  ? trace_hardirqs_on_caller+0xdd/0x1c0
  ? current_time+0x17/0x50
  ? trace_hardirqs_on+0xb/0x10
  generic_perform_write+0xa9/0x170
  __generic_file_write_iter+0x1a2/0x1f0
  ? f2fs_preallocate_blocks+0x137/0x160 [f2fs]
  f2fs_file_write_iter+0x6e/0x140 [f2fs]
  ? __lock_acquire+0x429/0x7b0
  __vfs_write+0xc1/0x140
  vfs_write+0x9b/0x190
  SyS_pwrite64+0x63/0xa0
  do_fast_syscall_32+0xa1/0x1b0
  entry_SYSENTER_32+0x4c/0x7b
 EIP: 0xb7786c61
 EFLAGS: 00000293 CPU: 2
 EAX: ffffffda EBX: 00000003 ECX: 08416000 EDX: 00001000
 ESI: 18b24000 EDI: 00000000 EBP: 00000003 ESP: bf9b36b0
  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b

Fixes: aaec2b1 ("f2fs: introduce cp_lock to protect updating of ckpt_flags")
Cc: [email protected]
Signed-off-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
0lvin pushed a commit to free-z4u/roc-rk3328-cc-official that referenced this issue Aug 17, 2019
Currently we pass a string argument to show_kernel_fault_diag() which
describes the reason for the fault. This is not being used so just
add a pr_info() which outputs the fault information.

With this change we get from:

|
| Path: /bin/busybox
| CPU: 0 PID: 92 Comm: modprobe Not tainted 4.12.0-rc6 rockchip-linux#30
| task: 9a254780 task.stack: 9a212000
|
| [ECR   ]: 0x00200400 => Other Fatal Err
|

to:

|
| Unhandled Machine Check Exception
| Path: /bin/busybox
| CPU: 0 PID: 92 Comm: modprobe Not tainted 4.12.0-rc6 rockchip-linux#37
| task: 9a240780 task.stack: 9a226000
|
|[ECR   ]: 0x00200400 => Machine Check (Other Fatal Err)
|

Which can help debugging.

Cc: Alexey Brodkin <[email protected]>
Signed-off-by: Jose Abreu <[email protected]>
Signed-off-by: Vineet Gupta <[email protected]>
0lvin pushed a commit to free-z4u/roc-rk3328-cc-official that referenced this issue Aug 20, 2019
…one script

The build messages for fdimage/isoimage generation are pretty unstructured,
just the raw shell command blocks are printed.

Emit shortened messages similar to existing kbuild messages, and move
the Makefile commands into a separate shell script - which is much
easier to handle.

This patch factors out the commands used for fdimage/isoimage generation
from arch/x86/boot/Makefile to a new script arch/x86/boot/genimage.sh.
Then it adds the new kbuild command 'genimage' which invokes the new script.
All fdimages/isoimage files are now generated by a call to 'genimage' with
different parameters.

Now 'make isoimage' becomes:

	...
	Kernel: arch/x86/boot/bzImage is ready  (rockchip-linux#30)
	  GENIMAGE arch/x86/boot/image.iso
	Size of boot image is 4 sectors -> No emulation
	 15.37% done, estimate finish Sun Nov  5 23:36:57 2017
	 30.68% done, estimate finish Sun Nov  5 23:36:57 2017
	 46.04% done, estimate finish Sun Nov  5 23:36:57 2017
	 61.35% done, estimate finish Sun Nov  5 23:36:57 2017
	 76.69% done, estimate finish Sun Nov  5 23:36:57 2017
	 92.00% done, estimate finish Sun Nov  5 23:36:57 2017
	Total translation table size: 2048
	Total rockridge attributes bytes: 659
	Total directory bytes: 0
	Path table size(bytes): 10
	Max brk space used 0
	32608 extents written (63 MB)
	Kernel: arch/x86/boot/image.iso is ready

Before:

	Kernel: arch/x86/boot/bzImage is ready  (rockchip-linux#63)
	rm -rf arch/x86/boot/isoimage
	mkdir arch/x86/boot/isoimage
	for i in lib lib64 share end ; do \
		if [ -f /usr/$i/syslinux/isolinux.bin ] ; then \
			cp /usr/$i/syslinux/isolinux.bin arch/x86/boot/isoimage ; \
			if [ -f /usr/$i/syslinux/ldlinux.c32 ]; then \
				cp /usr/$i/syslinux/ldlinux.c32 arch/x86/boot/isoimage ; \
			fi ; \
			break ; \
		fi ; \
		if [ $i = end ] ; then exit 1 ; fi ; \
	done
	...

Suggested-by: Ingo Molnar <[email protected]>
Signed-off-by: Changbin Du <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
0lvin pushed a commit to free-z4u/roc-rk3328-cc-official that referenced this issue Sep 21, 2019
I don't why we need take a single write lock and disable interrupts
while setting up debugfs. This is what what happens when we try anyway:

|ccp 0000:03:00.2: enabling device (0000 -> 0002)
|BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:69
|in_atomic(): 1, irqs_disabled(): 1, pid: 3, name: kworker/0:0
|irq event stamp: 17150
|hardirqs last  enabled at (17149): [<0000000097a18c49>] restore_regs_and_return_to_kernel+0x0/0x23
|hardirqs last disabled at (17150): [<000000000773b3a9>] _raw_write_lock_irqsave+0x1b/0x50
|softirqs last  enabled at (17148): [<0000000064d56155>] __do_softirq+0x3b8/0x4c1
|softirqs last disabled at (17125): [<0000000092633c18>] irq_exit+0xb1/0xc0
|CPU: 0 PID: 3 Comm: kworker/0:0 Not tainted 4.16.0-rc2+ rockchip-linux#30
|Workqueue: events work_for_cpu_fn
|Call Trace:
| dump_stack+0x7d/0xb6
| ___might_sleep+0x1eb/0x250
| down_write+0x17/0x60
| start_creating+0x4c/0xe0
| debugfs_create_dir+0x9/0x100
| ccp5_debugfs_setup+0x191/0x1b0
| ccp5_init+0x8a7/0x8c0
| ccp_dev_init+0xb8/0xe0
| sp_init+0x6c/0x90
| sp_pci_probe+0x26e/0x590
| local_pci_probe+0x3f/0x90
| work_for_cpu_fn+0x11/0x20
| process_one_work+0x1ff/0x650
| worker_thread+0x1d4/0x3a0
| kthread+0xfe/0x130
| ret_from_fork+0x27/0x50

If any locking is required, a simple mutex will do it.

Cc: Gary R Hook <[email protected]>
Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Acked-by: Gary R Hook <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>
0lvin pushed a commit to free-z4u/roc-rk3328-cc-official that referenced this issue Sep 28, 2019
syzbot reported a crash in tasklet_action_common() caused by dccp.

dccp needs to make sure socket wont disappear before tasklet handler
has completed.

This patch takes a reference on the socket when arming the tasklet,
and moves the sock_put() from dccp_write_xmit_timer() to dccp_write_xmitlet()

kernel BUG at kernel/softirq.c:514!
invalid opcode: 0000 [FireflyTeam#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 17 Comm: ksoftirqd/1 Not tainted 4.17.0-rc3+ rockchip-linux#30
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:tasklet_action_common.isra.19+0x6db/0x700 kernel/softirq.c:515
RSP: 0018:ffff8801d9b3faf8 EFLAGS: 00010246
dccp_close: ABORT with 65423 bytes unread
RAX: 1ffff1003b367f6b RBX: ffff8801daf1f3f0 RCX: 0000000000000000
RDX: ffff8801cf895498 RSI: 0000000000000004 RDI: 0000000000000000
RBP: ffff8801d9b3fc40 R08: ffffed0039f12a95 R09: ffffed0039f12a94
dccp_close: ABORT with 65423 bytes unread
R10: ffffed0039f12a94 R11: ffff8801cf8954a3 R12: 0000000000000000
R13: ffff8801d9b3fc18 R14: dffffc0000000000 R15: ffff8801cf895490
FS:  0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2bc28000 CR3: 00000001a08a9000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 tasklet_action+0x1d/0x20 kernel/softirq.c:533
 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:285
dccp_close: ABORT with 65423 bytes unread
 run_ksoftirqd+0x86/0x100 kernel/softirq.c:646
 smpboot_thread_fn+0x417/0x870 kernel/smpboot.c:164
 kthread+0x345/0x410 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412
Code: 48 8b 85 e8 fe ff ff 48 8b 95 f0 fe ff ff e9 94 fb ff ff 48 89 95 f0 fe ff ff e8 81 53 6e 00 48 8b 95 f0 fe ff ff e9 62 fb ff ff <0f> 0b 48 89 cf 48 89 8d e8 fe ff ff e8 64 53 6e 00 48 8b 8d e8
RIP: tasklet_action_common.isra.19+0x6db/0x700 kernel/softirq.c:515 RSP: ffff8801d9b3faf8

Fixes: dc841e3 ("dccp: Extend CCID packet dequeueing interface")
Signed-off-by: Eric Dumazet <[email protected]>
Reported-by: syzbot <[email protected]>
Cc: Gerrit Renker <[email protected]>
Cc: [email protected]
Signed-off-by: David S. Miller <[email protected]>
0lvin pushed a commit to free-z4u/roc-rk3328-cc-official that referenced this issue Sep 29, 2019
…nable()

[ Upstream commit 898bc40 ]

Fix au0828_analog_stream_enable() to check if device is in the right
state first. When unbind happens while bind is in progress, usbdev
pointer could be invalid in au0828_analog_stream_enable() and a call
to usb_ifnum_to_if() will result in the null pointer dereference.

This problem is found with the new media_dev_allocator.sh test.

kernel: [  590.359623] BUG: unable to handle kernel NULL pointer dereference at 00000000000004e8
kernel: [  590.359627] #PF error: [normal kernel read fault]
kernel: [  590.359629] PGD 0 P4D 0
kernel: [  590.359632] Oops: 0000 [FireflyTeam#1] SMP PTI
kernel: [  590.359634] CPU: 3 PID: 1458 Comm: v4l_id Not tainted 5.1.0-rc2+ rockchip-linux#30
kernel: [  590.359636] Hardware name: Dell Inc. OptiPlex 7 90/0HY9JP, BIOS A18 09/24/2013
kernel: [  590.359641] RIP: 0010:usb_ifnum_to_if+0x6/0x60
kernel: [  590.359643] Code: 5d 41 5e 41 5f 5d c3 48 83 c4
 10 b8 fa ff ff ff 5b 41 5c 41 5d 41 5e 41 5f 5d c3 b8 fa ff ff ff c3 0f 1f 00 6
6 66 66 66 90 55 <48> 8b 97 e8 04 00 00 48 89 e5 48 85 d2 74 41 0f b6 4a 04 84 c
9 74
kernel: [  590.359645] RSP: 0018:ffffad3cc3c1fc00 EFLAGS: 00010246
kernel: [  590.359646] RAX: 0000000000000000 RBX: ffff8ded b1f3c000 RCX: 1f377e4500000000
kernel: [  590.359648] RDX: ffff8dedfa3a6b50 RSI: 00000000 00000000 RDI: 0000000000000000
kernel: [  590.359649] RBP: ffffad3cc3c1fc28 R08: 00000000 8574acc2 R09: ffff8dedfa3a6b50
kernel: [  590.359650] R10: 0000000000000001 R11: 00000000 00000000 R12: 0000000000000000
kernel: [  590.359652] R13: ffff8dedb1f3f0f0 R14: ffffffff adcf7ec0 R15: 0000000000000000
kernel: [  590.359654] FS:  00007f7917198540(0000) GS:ffff 8dee258c0000(0000) knlGS:0000000000000000
kernel: [  590.359655] CS:  0010 DS: 0000 ES: 0000 CR0: 00 00000080050033
kernel: [  590.359657] CR2: 00000000000004e8 CR3: 00000001 a388e002 CR4: 00000000000606e0
kernel: [  590.359658] Call Trace:
kernel: [  590.359664]  ? au0828_analog_stream_enable+0x2c/0x180
kernel: [  590.359666]  au0828_v4l2_open+0xa4/0x110
kernel: [  590.359670]  v4l2_open+0x8b/0x120
kernel: [  590.359674]  chrdev_open+0xa6/0x1c0
kernel: [  590.359676]  ? cdev_put.part.3+0x20/0x20
kernel: [  590.359678]  do_dentry_open+0x1f6/0x360
kernel: [  590.359681]  vfs_open+0x2f/0x40
kernel: [  590.359684]  path_openat+0x299/0xc20
kernel: [  590.359688]  do_filp_open+0x9b/0x110
kernel: [  590.359695]  ? _raw_spin_unlock+0x27/0x40
kernel: [  590.359697]  ? __alloc_fd+0xb2/0x160
kernel: [  590.359700]  do_sys_open+0x1ba/0x260
kernel: [  590.359702]  ? do_sys_open+0x1ba/0x260
kernel: [  590.359712]  __x64_sys_openat+0x20/0x30
kernel: [  590.359715]  do_syscall_64+0x5a/0x120
kernel: [  590.359718]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Signed-off-by: Shuah Khan <[email protected]>
Signed-off-by: Hans Verkuil <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
0lvin pushed a commit to free-z4u/roc-rk3328-cc-official that referenced this issue Sep 29, 2019
[ Upstream commit 719c7d5 ]

BUG: KASAN: use-after-free in ip_vs_in.part.29+0xe8/0xd20 [ip_vs]
Read of size 4 at addr ffff8881e9b26e2c by task sshd/5603

CPU: 0 PID: 5603 Comm: sshd Not tainted 4.19.39+ rockchip-linux#30
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
Call Trace:
 dump_stack+0x71/0xab
 print_address_description+0x6a/0x270
 kasan_report+0x179/0x2c0
 ip_vs_in.part.29+0xe8/0xd20 [ip_vs]
 ip_vs_in+0xd8/0x170 [ip_vs]
 nf_hook_slow+0x5f/0xe0
 __ip_local_out+0x1d5/0x250
 ip_local_out+0x19/0x60
 __tcp_transmit_skb+0xba1/0x14f0
 tcp_write_xmit+0x41f/0x1ed0
 ? _copy_from_iter_full+0xca/0x340
 __tcp_push_pending_frames+0x52/0x140
 tcp_sendmsg_locked+0x787/0x1600
 ? tcp_sendpage+0x60/0x60
 ? inet_sk_set_state+0xb0/0xb0
 tcp_sendmsg+0x27/0x40
 sock_sendmsg+0x6d/0x80
 sock_write_iter+0x121/0x1c0
 ? sock_sendmsg+0x80/0x80
 __vfs_write+0x23e/0x370
 vfs_write+0xe7/0x230
 ksys_write+0xa1/0x120
 ? __ia32_sys_read+0x50/0x50
 ? __audit_syscall_exit+0x3ce/0x450
 do_syscall_64+0x73/0x200
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7ff6f6147c60
Code: 73 01 c3 48 8b 0d 28 12 2d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 5d 73 2d 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83
RSP: 002b:00007ffd772ead18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000034 RCX: 00007ff6f6147c60
RDX: 0000000000000034 RSI: 000055df30a31270 RDI: 0000000000000003
RBP: 000055df30a31270 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffd772ead70 R11: 0000000000000246 R12: 00007ffd772ead74
R13: 00007ffd772eae20 R14: 00007ffd772eae24 R15: 000055df2f12ddc0

Allocated by task 6052:
 kasan_kmalloc+0xa0/0xd0
 __kmalloc+0x10a/0x220
 ops_init+0x97/0x190
 register_pernet_operations+0x1ac/0x360
 register_pernet_subsys+0x24/0x40
 0xffffffffc0ea016d
 do_one_initcall+0x8b/0x253
 do_init_module+0xe3/0x335
 load_module+0x2fc0/0x3890
 __do_sys_finit_module+0x192/0x1c0
 do_syscall_64+0x73/0x200
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 6067:
 __kasan_slab_free+0x130/0x180
 kfree+0x90/0x1a0
 ops_free_list.part.7+0xa6/0xc0
 unregister_pernet_operations+0x18b/0x1f0
 unregister_pernet_subsys+0x1d/0x30
 ip_vs_cleanup+0x1d/0xd2f [ip_vs]
 __x64_sys_delete_module+0x20c/0x300
 do_syscall_64+0x73/0x200
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff8881e9b26600 which belongs to the cache kmalloc-4096 of size 4096
The buggy address is located 2092 bytes inside of 4096-byte region [ffff8881e9b26600, ffff8881e9b27600)
The buggy address belongs to the page:
page:ffffea0007a6c800 count:1 mapcount:0 mapping:ffff888107c0e600 index:0x0 compound_mapcount: 0
flags: 0x17ffffc0008100(slab|head)
raw: 0017ffffc0008100 dead000000000100 dead000000000200 ffff888107c0e600
raw: 0000000000000000 0000000080070007 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

while unregistering ipvs module, ops_free_list calls
__ip_vs_cleanup, then nf_unregister_net_hooks be called to
do remove nf hook entries. It need a RCU period to finish,
however net->ipvs is set to NULL immediately, which will
trigger NULL pointer dereference when a packet is hooked
and handled by ip_vs_in where net->ipvs is dereferenced.

Another scene is ops_free_list call ops_free to free the
net_generic directly while __ip_vs_cleanup finished, then
calling ip_vs_in will triggers use-after-free.

This patch moves nf_unregister_net_hooks from __ip_vs_cleanup()
to __ip_vs_dev_cleanup(),  where rcu_barrier() is called by
unregister_pernet_device -> unregister_pernet_operations,
that will do the needed grace period.

Reported-by: Hulk Robot <[email protected]>
Fixes: efe4160 ("ipvs: convert to use pernet nf_hook api")
Suggested-by: Julian Anastasov <[email protected]>
Signed-off-by: YueHaibing <[email protected]>
Acked-by: Julian Anastasov <[email protected]>
Signed-off-by: Simon Horman <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
0lvin pushed a commit to free-z4u/roc-rk3328-cc-official that referenced this issue Oct 5, 2019
Crash dump shows following instructions

crash> bt
PID: 0      TASK: ffffffffbe412480  CPU: 0   COMMAND: "swapper/0"
 #0 [ffff891ee0003868] machine_kexec at ffffffffbd063ef1
 FireflyTeam#1 [ffff891ee00038c8] __crash_kexec at ffffffffbd12b6f2
 FireflyTeam#2 [ffff891ee0003998] crash_kexec at ffffffffbd12c84c
 FireflyTeam#3 [ffff891ee00039b8] oops_end at ffffffffbd030f0a
 FireflyTeam#4 [ffff891ee00039e0] no_context at ffffffffbd074643
 FireflyTeam#5 [ffff891ee0003a40] __bad_area_nosemaphore at ffffffffbd07496e
 FireflyTeam#6 [ffff891ee0003a90] bad_area_nosemaphore at ffffffffbd074a64
 FireflyTeam#7 [ffff891ee0003aa0] __do_page_fault at ffffffffbd074b0a
 FireflyTeam#8 [ffff891ee0003b18] do_page_fault at ffffffffbd074fc8
 FireflyTeam#9 [ffff891ee0003b50] page_fault at ffffffffbda01925
    [exception RIP: qlt_schedule_sess_for_deletion+15]
    RIP: ffffffffc02e526f  RSP: ffff891ee0003c08  RFLAGS: 00010046
    RAX: 0000000000000000  RBX: 0000000000000000  RCX: ffffffffc0307847
    RDX: 00000000000020e6  RSI: ffff891edbc377c8  RDI: 0000000000000000
    RBP: ffff891ee0003c18   R8: ffffffffc02f0b20   R9: 0000000000000250
    R10: 0000000000000258  R11: 000000000000b780  R12: ffff891ed9b43000
    R13: 00000000000000f0  R14: 0000000000000006  R15: ffff891edbc377c8
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 FireflyTeam#10 [ffff891ee0003c20] qla2x00_fcport_event_handler at ffffffffc02853d3 [qla2xxx]
 FireflyTeam#11 [ffff891ee0003cf0] __dta_qla24xx_async_gnl_sp_done_333 at ffffffffc0285a1d [qla2xxx]
 FireflyTeam#12 [ffff891ee0003de8] qla24xx_process_response_queue at ffffffffc02a2eb5 [qla2xxx]
 FireflyTeam#13 [ffff891ee0003e88] qla24xx_msix_rsp_q at ffffffffc02a5403 [qla2xxx]
 FireflyTeam#14 [ffff891ee0003ec0] __handle_irq_event_percpu at ffffffffbd0f4c59
 FireflyTeam#15 [ffff891ee0003f10] handle_irq_event_percpu at ffffffffbd0f4e02
 FireflyTeam#16 [ffff891ee0003f40] handle_irq_event at ffffffffbd0f4e90
 rockchip-linux#17 [ffff891ee0003f68] handle_edge_irq at ffffffffbd0f8984
 rockchip-linux#18 [ffff891ee0003f88] handle_irq at ffffffffbd0305d5
 rockchip-linux#19 [ffff891ee0003fb8] do_IRQ at ffffffffbda02a18
 --- <IRQ stack> ---
 rockchip-linux#20 [ffffffffbe403d30] ret_from_intr at ffffffffbda0094e
    [exception RIP: unknown or invalid address]
    RIP: 000000000000001f  RSP: 0000000000000000  RFLAGS: fff3b8c2091ebb3f
    RAX: ffffbba5a0000200  RBX: 0000be8cdfa8f9fa  RCX: 0000000000000018
    RDX: 0000000000000101  RSI: 000000000000015d  RDI: 0000000000000193
    RBP: 0000000000000083   R8: ffffffffbe403e38   R9: 0000000000000002
    R10: 0000000000000000  R11: ffffffffbe56b820  R12: ffff891ee001cf00
    R13: ffffffffbd11c0a4  R14: ffffffffbe403d60  R15: 0000000000000001
    ORIG_RAX: ffff891ee0022ac0  CS: 0000  SS: ffffffffffffffb9
 bt: WARNING: possibly bogus exception frame
 rockchip-linux#21 [ffffffffbe403dd8] cpuidle_enter_state at ffffffffbd67c6fd
 rockchip-linux#22 [ffffffffbe403e40] cpuidle_enter at ffffffffbd67c907
 rockchip-linux#23 [ffffffffbe403e50] call_cpuidle at ffffffffbd0d98f3
 rockchip-linux#24 [ffffffffbe403e60] do_idle at ffffffffbd0d9b42
 rockchip-linux#25 [ffffffffbe403e98] cpu_startup_entry at ffffffffbd0d9da3
 rockchip-linux#26 [ffffffffbe403ec0] rest_init at ffffffffbd81d4aa
 rockchip-linux#27 [ffffffffbe403ed0] start_kernel at ffffffffbe67d2ca
 rockchip-linux#28 [ffffffffbe403f28] x86_64_start_reservations at ffffffffbe67c675
 rockchip-linux#29 [ffffffffbe403f38] x86_64_start_kernel at ffffffffbe67c6eb
 rockchip-linux#30 [ffffffffbe403f50] secondary_startup_64 at ffffffffbd0000d5

Fixes: 040036b ("scsi: qla2xxx: Delay loop id allocation at login")
Cc: <[email protected]> # v4.17+
Signed-off-by: Chuck Anderson <[email protected]>
Signed-off-by: Himanshu Madhani <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
0lvin pushed a commit to free-z4u/roc-rk3328-cc-official that referenced this issue Oct 11, 2019
In l2tp code, if it is a L2TP_UDP_ENCAP tunnel, tunnel->sk points to a
UDP socket. User could call sendmsg() on both this tunnel and the UDP
socket itself concurrently. As l2tp_xmit_skb() holds socket lock and call
__sk_dst_check() to refresh sk->sk_dst_cache, while udpv6_sendmsg() is
lockless and call sk_dst_check() to refresh sk->sk_dst_cache, there
could be a race and cause the dst cache to be freed multiple times.
So we fix l2tp side code to always call sk_dst_check() to garantee
xchg() is called when refreshing sk->sk_dst_cache to avoid race
conditions.

Syzkaller reported stack trace:
BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
BUG: KASAN: use-after-free in atomic_fetch_add_unless include/linux/atomic.h:575 [inline]
BUG: KASAN: use-after-free in atomic_add_unless include/linux/atomic.h:597 [inline]
BUG: KASAN: use-after-free in dst_hold_safe include/net/dst.h:308 [inline]
BUG: KASAN: use-after-free in ip6_hold_safe+0xe6/0x670 net/ipv6/route.c:1029
Read of size 4 at addr ffff8801aea9a880 by task syz-executor129/4829

CPU: 0 PID: 4829 Comm: syz-executor129 Not tainted 4.18.0-rc7-next-20180802+ rockchip-linux#30
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272
 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
 atomic_fetch_add_unless include/linux/atomic.h:575 [inline]
 atomic_add_unless include/linux/atomic.h:597 [inline]
 dst_hold_safe include/net/dst.h:308 [inline]
 ip6_hold_safe+0xe6/0x670 net/ipv6/route.c:1029
 rt6_get_pcpu_route net/ipv6/route.c:1249 [inline]
 ip6_pol_route+0x354/0xd20 net/ipv6/route.c:1922
 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2098
 fib6_rule_lookup+0x283/0x890 net/ipv6/fib6_rules.c:122
 ip6_route_output_flags+0x2c5/0x350 net/ipv6/route.c:2126
 ip6_dst_lookup_tail+0x1278/0x1da0 net/ipv6/ip6_output.c:978
 ip6_dst_lookup_flow+0xc8/0x270 net/ipv6/ip6_output.c:1079
 ip6_sk_dst_lookup_flow+0x5ed/0xc50 net/ipv6/ip6_output.c:1117
 udpv6_sendmsg+0x2163/0x36b0 net/ipv6/udp.c:1354
 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:632
 ___sys_sendmsg+0x51d/0x930 net/socket.c:2115
 __sys_sendmmsg+0x240/0x6f0 net/socket.c:2210
 __do_sys_sendmmsg net/socket.c:2239 [inline]
 __se_sys_sendmmsg net/socket.c:2236 [inline]
 __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2236
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x446a29
Code: e8 ac b8 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f4de5532db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000006dcc38 RCX: 0000000000446a29
RDX: 00000000000000b8 RSI: 0000000020001b00 RDI: 0000000000000003
RBP: 00000000006dcc30 R08: 00007f4de5533700 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc3c
R13: 00007ffe2b830fdf R14: 00007f4de55339c0 R15: 0000000000000001

Fixes: 71b1391 ("l2tp: ensure sk->dst is still valid")
Reported-by: [email protected]
Signed-off-by: Wei Wang <[email protected]>
Signed-off-by: Martin KaFai Lau <[email protected]>
Cc: Guillaume Nault <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Cong Wang <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
friendlyarm pushed a commit to friendlyarm/kernel-rockchip that referenced this issue Aug 31, 2020
[ Upstream commit 83f3522 ]

fib_trie_unmerge() is called with RTNL held, but not from an RCU
read-side critical section. This leads to the following warning [1] when
the FIB alias list in a leaf is traversed with
hlist_for_each_entry_rcu().

Since the function is always called with RTNL held and since
modification of the list is protected by RTNL, simply use
hlist_for_each_entry() and silence the warning.

[1]
WARNING: suspicious RCU usage
5.8.0-rc4-custom-01520-gc1f937f3f83b rockchip-linux#30 Not tainted
-----------------------------
net/ipv4/fib_trie.c:1867 RCU-list traversed in non-reader section!!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by ip/164:
 #0: ffffffff85a27850 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x49a/0xbd0

stack backtrace:
CPU: 0 PID: 164 Comm: ip Not tainted 5.8.0-rc4-custom-01520-gc1f937f3f83b rockchip-linux#30
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
 dump_stack+0x100/0x184
 lockdep_rcu_suspicious+0x153/0x15d
 fib_trie_unmerge+0x608/0xdb0
 fib_unmerge+0x44/0x360
 fib4_rule_configure+0xc8/0xad0
 fib_nl_newrule+0x37a/0x1dd0
 rtnetlink_rcv_msg+0x4f7/0xbd0
 netlink_rcv_skb+0x17a/0x480
 rtnetlink_rcv+0x22/0x30
 netlink_unicast+0x5ae/0x890
 netlink_sendmsg+0x98a/0xf40
 ____sys_sendmsg+0x879/0xa00
 ___sys_sendmsg+0x122/0x190
 __sys_sendmsg+0x103/0x1d0
 __x64_sys_sendmsg+0x7d/0xb0
 do_syscall_64+0x54/0xa0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fc80a234e97
Code: Bad RIP value.
RSP: 002b:00007ffef8b66798 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc80a234e97
RDX: 0000000000000000 RSI: 00007ffef8b66800 RDI: 0000000000000003
RBP: 000000005f141b1c R08: 0000000000000001 R09: 0000000000000000
R10: 00007fc80a2a8ac0 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 00007ffef8b67008 R15: 0000556fccb10020

Fixes: 0ddcf43 ("ipv4: FIB Local/MAIN table collapse")
Signed-off-by: Ido Schimmel <[email protected]>
Reviewed-by: Jiri Pirko <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
rkchrome pushed a commit that referenced this issue Oct 10, 2020
[ Upstream commit 96298f6 ]

According to Core Spec Version 5.2 | Vol 3, Part A 6.1.5,
the incoming L2CAP_ConfigReq should be handled during
OPEN state.

The section below shows the btmon trace when running
L2CAP/COS/CFD/BV-12-C before and after this change.

=== Before ===
...
> ACL Data RX: Handle 256 flags 0x02 dlen 12                #22
      L2CAP: Connection Request (0x02) ident 2 len 4
        PSM: 1 (0x0001)
        Source CID: 65
< ACL Data TX: Handle 256 flags 0x00 dlen 16                #23
      L2CAP: Connection Response (0x03) ident 2 len 8
        Destination CID: 64
        Source CID: 65
        Result: Connection successful (0x0000)
        Status: No further information available (0x0000)
< ACL Data TX: Handle 256 flags 0x00 dlen 12                #24
      L2CAP: Configure Request (0x04) ident 2 len 4
        Destination CID: 65
        Flags: 0x0000
> HCI Event: Number of Completed Packets (0x13) plen 5      #25
        Num handles: 1
        Handle: 256
        Count: 1
> HCI Event: Number of Completed Packets (0x13) plen 5      #26
        Num handles: 1
        Handle: 256
        Count: 1
> ACL Data RX: Handle 256 flags 0x02 dlen 16                #27
      L2CAP: Configure Request (0x04) ident 3 len 8
        Destination CID: 64
        Flags: 0x0000
        Option: Unknown (0x10) [hint]
        01 00                                            ..
< ACL Data TX: Handle 256 flags 0x00 dlen 18                #28
      L2CAP: Configure Response (0x05) ident 3 len 10
        Source CID: 65
        Flags: 0x0000
        Result: Success (0x0000)
        Option: Maximum Transmission Unit (0x01) [mandatory]
          MTU: 672
> HCI Event: Number of Completed Packets (0x13) plen 5      #29
        Num handles: 1
        Handle: 256
        Count: 1
> ACL Data RX: Handle 256 flags 0x02 dlen 14                #30
      L2CAP: Configure Response (0x05) ident 2 len 6
        Source CID: 64
        Flags: 0x0000
        Result: Success (0x0000)
> ACL Data RX: Handle 256 flags 0x02 dlen 20                #31
      L2CAP: Configure Request (0x04) ident 3 len 12
        Destination CID: 64
        Flags: 0x0000
        Option: Unknown (0x10) [hint]
        01 00 91 02 11 11                                ......
< ACL Data TX: Handle 256 flags 0x00 dlen 14                #32
      L2CAP: Command Reject (0x01) ident 3 len 6
        Reason: Invalid CID in request (0x0002)
        Destination CID: 64
        Source CID: 65
> HCI Event: Number of Completed Packets (0x13) plen 5      #33
        Num handles: 1
        Handle: 256
        Count: 1
...
=== After ===
...
> ACL Data RX: Handle 256 flags 0x02 dlen 12               #22
      L2CAP: Connection Request (0x02) ident 2 len 4
        PSM: 1 (0x0001)
        Source CID: 65
< ACL Data TX: Handle 256 flags 0x00 dlen 16               #23
      L2CAP: Connection Response (0x03) ident 2 len 8
        Destination CID: 64
        Source CID: 65
        Result: Connection successful (0x0000)
        Status: No further information available (0x0000)
< ACL Data TX: Handle 256 flags 0x00 dlen 12               #24
      L2CAP: Configure Request (0x04) ident 2 len 4
        Destination CID: 65
        Flags: 0x0000
> HCI Event: Number of Completed Packets (0x13) plen 5     #25
        Num handles: 1
        Handle: 256
        Count: 1
> HCI Event: Number of Completed Packets (0x13) plen 5     #26
        Num handles: 1
        Handle: 256
        Count: 1
> ACL Data RX: Handle 256 flags 0x02 dlen 16               #27
      L2CAP: Configure Request (0x04) ident 3 len 8
        Destination CID: 64
        Flags: 0x0000
        Option: Unknown (0x10) [hint]
        01 00                                            ..
< ACL Data TX: Handle 256 flags 0x00 dlen 18               #28
      L2CAP: Configure Response (0x05) ident 3 len 10
        Source CID: 65
        Flags: 0x0000
        Result: Success (0x0000)
        Option: Maximum Transmission Unit (0x01) [mandatory]
          MTU: 672
> HCI Event: Number of Completed Packets (0x13) plen 5     #29
        Num handles: 1
        Handle: 256
        Count: 1
> ACL Data RX: Handle 256 flags 0x02 dlen 14               #30
      L2CAP: Configure Response (0x05) ident 2 len 6
        Source CID: 64
        Flags: 0x0000
        Result: Success (0x0000)
> ACL Data RX: Handle 256 flags 0x02 dlen 20               #31
      L2CAP: Configure Request (0x04) ident 3 len 12
        Destination CID: 64
        Flags: 0x0000
        Option: Unknown (0x10) [hint]
        01 00 91 02 11 11                                .....
< ACL Data TX: Handle 256 flags 0x00 dlen 18               #32
      L2CAP: Configure Response (0x05) ident 3 len 10
        Source CID: 65
        Flags: 0x0000
        Result: Success (0x0000)
        Option: Maximum Transmission Unit (0x01) [mandatory]
          MTU: 672
< ACL Data TX: Handle 256 flags 0x00 dlen 12               #33
      L2CAP: Configure Request (0x04) ident 3 len 4
        Destination CID: 65
        Flags: 0x0000
> HCI Event: Number of Completed Packets (0x13) plen 5     #34
        Num handles: 1
        Handle: 256
        Count: 1
> HCI Event: Number of Completed Packets (0x13) plen 5     #35
        Num handles: 1
        Handle: 256
        Count: 1
...

Signed-off-by: Howard Chung <[email protected]>
Signed-off-by: Marcel Holtmann <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
friendlyarm pushed a commit to friendlyarm/kernel-rockchip that referenced this issue Jun 15, 2021
[ Upstream commit 0f20615 ]

Fix BPF_CORE_READ_BITFIELD() macro used for reading CO-RE-relocatable
bitfields. Missing breaks in a switch caused 8-byte reads always. This can
confuse libbpf because it does strict checks that memory load size corresponds
to the original size of the field, which in this case quite often would be
wrong.

After fixing that, we run into another problem, which quite subtle, so worth
documenting here. The issue is in Clang optimization and CO-RE relocation
interactions. Without that asm volatile construct (also known as
barrier_var()), Clang will re-order BYTE_OFFSET and BYTE_SIZE relocations and
will apply BYTE_OFFSET 4 times for each switch case arm. This will result in
the same error from libbpf about mismatch of memory load size and original
field size. I.e., if we were reading u32, we'd still have *(u8 *), *(u16 *),
*(u32 *), and *(u64 *) memory loads, three of which will fail. Using
barrier_var() forces Clang to apply BYTE_OFFSET relocation first (and once) to
calculate p, after which value of p is used without relocation in each of
switch case arms, doing appropiately-sized memory load.

Here's the list of relevant relocations and pieces of generated BPF code
before and after this patch for test_core_reloc_bitfields_direct selftests.

BEFORE
=====
 rockchip-linux#45: core_reloc: insn rockchip-linux#160 --> [5] + 0:5: byte_sz --> struct core_reloc_bitfields.u32
 rockchip-linux#46: core_reloc: insn rockchip-linux#167 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32
 rockchip-linux#47: core_reloc: insn rockchip-linux#174 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32
 rockchip-linux#48: core_reloc: insn rockchip-linux#178 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32
 rockchip-linux#49: core_reloc: insn rockchip-linux#182 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32

     157:       18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r2 = 0 ll
     159:       7b 12 20 01 00 00 00 00 *(u64 *)(r2 + 288) = r1
     160:       b7 02 00 00 04 00 00 00 r2 = 4
; BYTE_SIZE relocation here                 ^^^
     161:       66 02 07 00 03 00 00 00 if w2 s> 3 goto +7 <LBB0_63>
     162:       16 02 0d 00 01 00 00 00 if w2 == 1 goto +13 <LBB0_65>
     163:       16 02 01 00 02 00 00 00 if w2 == 2 goto +1 <LBB0_66>
     164:       05 00 12 00 00 00 00 00 goto +18 <LBB0_69>

0000000000000528 <LBB0_66>:
     165:       18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll
     167:       69 11 08 00 00 00 00 00 r1 = *(u16 *)(r1 + 8)
; BYTE_OFFSET relo here w/ WRONG size        ^^^^^^^^^^^^^^^^
     168:       05 00 0e 00 00 00 00 00 goto +14 <LBB0_69>

0000000000000548 <LBB0_63>:
     169:       16 02 0a 00 04 00 00 00 if w2 == 4 goto +10 <LBB0_67>
     170:       16 02 01 00 08 00 00 00 if w2 == 8 goto +1 <LBB0_68>
     171:       05 00 0b 00 00 00 00 00 goto +11 <LBB0_69>

0000000000000560 <LBB0_68>:
     172:       18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll
     174:       79 11 08 00 00 00 00 00 r1 = *(u64 *)(r1 + 8)
; BYTE_OFFSET relo here w/ WRONG size        ^^^^^^^^^^^^^^^^
     175:       05 00 07 00 00 00 00 00 goto +7 <LBB0_69>

0000000000000580 <LBB0_65>:
     176:       18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll
     178:       71 11 08 00 00 00 00 00 r1 = *(u8 *)(r1 + 8)
; BYTE_OFFSET relo here w/ WRONG size        ^^^^^^^^^^^^^^^^
     179:       05 00 03 00 00 00 00 00 goto +3 <LBB0_69>

00000000000005a0 <LBB0_67>:
     180:       18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll
     182:       61 11 08 00 00 00 00 00 r1 = *(u32 *)(r1 + 8)
; BYTE_OFFSET relo here w/ RIGHT size        ^^^^^^^^^^^^^^^^

00000000000005b8 <LBB0_69>:
     183:       67 01 00 00 20 00 00 00 r1 <<= 32
     184:       b7 02 00 00 00 00 00 00 r2 = 0
     185:       16 02 02 00 00 00 00 00 if w2 == 0 goto +2 <LBB0_71>
     186:       c7 01 00 00 20 00 00 00 r1 s>>= 32
     187:       05 00 01 00 00 00 00 00 goto +1 <LBB0_72>

00000000000005e0 <LBB0_71>:
     188:       77 01 00 00 20 00 00 00 r1 >>= 32

AFTER
=====

 rockchip-linux#30: core_reloc: insn rockchip-linux#132 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32
 rockchip-linux#31: core_reloc: insn rockchip-linux#134 --> [5] + 0:5: byte_sz --> struct core_reloc_bitfields.u32

     129:       18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r2 = 0 ll
     131:       7b 12 20 01 00 00 00 00 *(u64 *)(r2 + 288) = r1
     132:       b7 01 00 00 08 00 00 00 r1 = 8
; BYTE_OFFSET relo here                     ^^^
; no size check for non-memory dereferencing instructions
     133:       0f 12 00 00 00 00 00 00 r2 += r1
     134:       b7 03 00 00 04 00 00 00 r3 = 4
; BYTE_SIZE relocation here                 ^^^
     135:       66 03 05 00 03 00 00 00 if w3 s> 3 goto +5 <LBB0_63>
     136:       16 03 09 00 01 00 00 00 if w3 == 1 goto +9 <LBB0_65>
     137:       16 03 01 00 02 00 00 00 if w3 == 2 goto +1 <LBB0_66>
     138:       05 00 0a 00 00 00 00 00 goto +10 <LBB0_69>

0000000000000458 <LBB0_66>:
     139:       69 21 00 00 00 00 00 00 r1 = *(u16 *)(r2 + 0)
; NO CO-RE relocation here                   ^^^^^^^^^^^^^^^^
     140:       05 00 08 00 00 00 00 00 goto +8 <LBB0_69>

0000000000000468 <LBB0_63>:
     141:       16 03 06 00 04 00 00 00 if w3 == 4 goto +6 <LBB0_67>
     142:       16 03 01 00 08 00 00 00 if w3 == 8 goto +1 <LBB0_68>
     143:       05 00 05 00 00 00 00 00 goto +5 <LBB0_69>

0000000000000480 <LBB0_68>:
     144:       79 21 00 00 00 00 00 00 r1 = *(u64 *)(r2 + 0)
; NO CO-RE relocation here                   ^^^^^^^^^^^^^^^^
     145:       05 00 03 00 00 00 00 00 goto +3 <LBB0_69>

0000000000000490 <LBB0_65>:
     146:       71 21 00 00 00 00 00 00 r1 = *(u8 *)(r2 + 0)
; NO CO-RE relocation here                   ^^^^^^^^^^^^^^^^
     147:       05 00 01 00 00 00 00 00 goto +1 <LBB0_69>

00000000000004a0 <LBB0_67>:
     148:       61 21 00 00 00 00 00 00 r1 = *(u32 *)(r2 + 0)
; NO CO-RE relocation here                   ^^^^^^^^^^^^^^^^

00000000000004a8 <LBB0_69>:
     149:       67 01 00 00 20 00 00 00 r1 <<= 32
     150:       b7 02 00 00 00 00 00 00 r2 = 0
     151:       16 02 02 00 00 00 00 00 if w2 == 0 goto +2 <LBB0_71>
     152:       c7 01 00 00 20 00 00 00 r1 s>>= 32
     153:       05 00 01 00 00 00 00 00 goto +1 <LBB0_72>

00000000000004d0 <LBB0_71>:
     154:       77 01 00 00 20 00 00 00 r1 >>= 323

Fixes: ee26dad ("libbpf: Add support for relocatable bitfields")
Signed-off-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Lorenz Bauer <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
Caesar-github pushed a commit that referenced this issue Sep 3, 2022
With RT_FULL we get the below wreckage:

[  126.060484] =======================================================
[  126.060486] [ INFO: possible circular locking dependency detected ]
[  126.060489] 3.0.1-rt10+ #30
[  126.060490] -------------------------------------------------------
[  126.060492] irq/24-eth0/1235 is trying to acquire lock:
[  126.060495]  (&(lock)->wait_lock#2){+.+...}, at: [<ffffffff81501c81>] rt_mutex_slowunlock+0x16/0x55
[  126.060503] 
[  126.060504] but task is already holding lock:
[  126.060506]  (&p->pi_lock){-...-.}, at: [<ffffffff81074fdc>] try_to_wake_up+0x35/0x429
[  126.060511] 
[  126.060511] which lock already depends on the new lock.
[  126.060513] 
[  126.060514] 
[  126.060514] the existing dependency chain (in reverse order) is:
[  126.060516] 
[  126.060516] -> #1 (&p->pi_lock){-...-.}:
[  126.060519]        [<ffffffff810afe9e>] lock_acquire+0x145/0x18a
[  126.060524]        [<ffffffff8150291e>] _raw_spin_lock_irqsave+0x4b/0x85
[  126.060527]        [<ffffffff810b5aa4>] task_blocks_on_rt_mutex+0x36/0x20f
[  126.060531]        [<ffffffff815019bb>] rt_mutex_slowlock+0xd1/0x15a
[  126.060534]        [<ffffffff81501ae3>] rt_mutex_lock+0x2d/0x2f
[  126.060537]        [<ffffffff810d9020>] rcu_boost+0xad/0xde
[  126.060541]        [<ffffffff810d90ce>] rcu_boost_kthread+0x7d/0x9b
[  126.060544]        [<ffffffff8109a760>] kthread+0x99/0xa1
[  126.060547]        [<ffffffff81509b14>] kernel_thread_helper+0x4/0x10
[  126.060551] 
[  126.060552] -> #0 (&(lock)->wait_lock#2){+.+...}:
[  126.060555]        [<ffffffff810af1b8>] __lock_acquire+0x1157/0x1816
[  126.060558]        [<ffffffff810afe9e>] lock_acquire+0x145/0x18a
[  126.060561]        [<ffffffff8150279e>] _raw_spin_lock+0x40/0x73
[  126.060564]        [<ffffffff81501c81>] rt_mutex_slowunlock+0x16/0x55
[  126.060566]        [<ffffffff81501ce7>] rt_mutex_unlock+0x27/0x29
[  126.060569]        [<ffffffff810d9f86>] rcu_read_unlock_special+0x17e/0x1c4
[  126.060573]        [<ffffffff810da014>] __rcu_read_unlock+0x48/0x89
[  126.060576]        [<ffffffff8106847a>] select_task_rq_rt+0xc7/0xd5
[  126.060580]        [<ffffffff8107511c>] try_to_wake_up+0x175/0x429
[  126.060583]        [<ffffffff81075425>] wake_up_process+0x15/0x17
[  126.060585]        [<ffffffff81080a51>] wakeup_softirqd+0x24/0x26
[  126.060590]        [<ffffffff81081df9>] irq_exit+0x49/0x55
[  126.060593]        [<ffffffff8150a3bd>] smp_apic_timer_interrupt+0x8a/0x98
[  126.060597]        [<ffffffff81509793>] apic_timer_interrupt+0x13/0x20
[  126.060600]        [<ffffffff810d5952>] irq_forced_thread_fn+0x1b/0x44
[  126.060603]        [<ffffffff810d582c>] irq_thread+0xde/0x1af
[  126.060606]        [<ffffffff8109a760>] kthread+0x99/0xa1
[  126.060608]        [<ffffffff81509b14>] kernel_thread_helper+0x4/0x10
[  126.060611] 
[  126.060612] other info that might help us debug this:
[  126.060614] 
[  126.060615]  Possible unsafe locking scenario:
[  126.060616] 
[  126.060617]        CPU0                    CPU1
[  126.060619]        ----                    ----
[  126.060620]   lock(&p->pi_lock);
[  126.060623]                                lock(&(lock)->wait_lock);
[  126.060625]                                lock(&p->pi_lock);
[  126.060627]   lock(&(lock)->wait_lock);
[  126.060629] 
[  126.060629]  *** DEADLOCK ***
[  126.060630] 
[  126.060632] 1 lock held by irq/24-eth0/1235:
[  126.060633]  #0:  (&p->pi_lock){-...-.}, at: [<ffffffff81074fdc>] try_to_wake_up+0x35/0x429
[  126.060638] 
[  126.060638] stack backtrace:
[  126.060641] Pid: 1235, comm: irq/24-eth0 Not tainted 3.0.1-rt10+ #30
[  126.060643] Call Trace:
[  126.060644]  <IRQ>  [<ffffffff810acbde>] print_circular_bug+0x289/0x29a
[  126.060651]  [<ffffffff810af1b8>] __lock_acquire+0x1157/0x1816
[  126.060655]  [<ffffffff810ab3aa>] ? trace_hardirqs_off_caller+0x1f/0x99
[  126.060658]  [<ffffffff81501c81>] ? rt_mutex_slowunlock+0x16/0x55
[  126.060661]  [<ffffffff810afe9e>] lock_acquire+0x145/0x18a
[  126.060664]  [<ffffffff81501c81>] ? rt_mutex_slowunlock+0x16/0x55
[  126.060668]  [<ffffffff8150279e>] _raw_spin_lock+0x40/0x73
[  126.060671]  [<ffffffff81501c81>] ? rt_mutex_slowunlock+0x16/0x55
[  126.060674]  [<ffffffff810d9655>] ? rcu_report_qs_rsp+0x87/0x8c
[  126.060677]  [<ffffffff81501c81>] rt_mutex_slowunlock+0x16/0x55
[  126.060680]  [<ffffffff810d9ea3>] ? rcu_read_unlock_special+0x9b/0x1c4
[  126.060683]  [<ffffffff81501ce7>] rt_mutex_unlock+0x27/0x29
[  126.060687]  [<ffffffff810d9f86>] rcu_read_unlock_special+0x17e/0x1c4
[  126.060690]  [<ffffffff810da014>] __rcu_read_unlock+0x48/0x89
[  126.060693]  [<ffffffff8106847a>] select_task_rq_rt+0xc7/0xd5
[  126.060696]  [<ffffffff810683da>] ? select_task_rq_rt+0x27/0xd5
[  126.060701]  [<ffffffff810a852a>] ? clockevents_program_event+0x8e/0x90
[  126.060704]  [<ffffffff8107511c>] try_to_wake_up+0x175/0x429
[  126.060708]  [<ffffffff810a95dc>] ? tick_program_event+0x1f/0x21
[  126.060711]  [<ffffffff81075425>] wake_up_process+0x15/0x17
[  126.060715]  [<ffffffff81080a51>] wakeup_softirqd+0x24/0x26
[  126.060718]  [<ffffffff81081df9>] irq_exit+0x49/0x55
[  126.060721]  [<ffffffff8150a3bd>] smp_apic_timer_interrupt+0x8a/0x98
[  126.060724]  [<ffffffff81509793>] apic_timer_interrupt+0x13/0x20
[  126.060726]  <EOI>  [<ffffffff81072855>] ? migrate_disable+0x75/0x12d
[  126.060733]  [<ffffffff81080a61>] ? local_bh_disable+0xe/0x1f
[  126.060736]  [<ffffffff81080a70>] ? local_bh_disable+0x1d/0x1f
[  126.060739]  [<ffffffff810d5952>] irq_forced_thread_fn+0x1b/0x44
[  126.060742]  [<ffffffff81502ac0>] ? _raw_spin_unlock_irq+0x3b/0x59
[  126.060745]  [<ffffffff810d582c>] irq_thread+0xde/0x1af
[  126.060748]  [<ffffffff810d5937>] ? irq_thread_fn+0x3a/0x3a
[  126.060751]  [<ffffffff810d574e>] ? irq_finalize_oneshot+0xd1/0xd1
[  126.060754]  [<ffffffff810d574e>] ? irq_finalize_oneshot+0xd1/0xd1
[  126.060757]  [<ffffffff8109a760>] kthread+0x99/0xa1
[  126.060761]  [<ffffffff81509b14>] kernel_thread_helper+0x4/0x10
[  126.060764]  [<ffffffff81069ed7>] ? finish_task_switch+0x87/0x10a
[  126.060768]  [<ffffffff81502ec4>] ? retint_restore_args+0xe/0xe
[  126.060771]  [<ffffffff8109a6c7>] ? __init_kthread_worker+0x8c/0x8c
[  126.060774]  [<ffffffff81509b10>] ? gs_change+0xb/0xb

Because irq_exit() does:

void irq_exit(void)
{
	account_system_vtime(current);
	trace_hardirq_exit();
	sub_preempt_count(IRQ_EXIT_OFFSET);
	if (!in_interrupt() && local_softirq_pending())
		invoke_softirq();

	...
}

Which triggers a wakeup, which uses RCU, now if the interrupted task has
t->rcu_read_unlock_special set, the rcu usage from the wakeup will end
up in rcu_read_unlock_special(). rcu_read_unlock_special() will test
for in_irq(), which will fail as we just decremented preempt_count
with IRQ_EXIT_OFFSET, and in_sering_softirq(), which for
PREEMPT_RT_FULL reads:

int in_serving_softirq(void)
{
	int res;

	preempt_disable();
	res = __get_cpu_var(local_softirq_runner) == current;
	preempt_enable();
	return res;
}

Which will thus also fail, resulting in the above wreckage.

The 'somewhat' ugly solution is to open-code the preempt_count() test
in rcu_read_unlock_special().

Also, we're not at all sure how ->rcu_read_unlock_special gets set
here... so this is very likely a bandaid and more thought is required.

Cc: Paul E. McKenney <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
hejiawencc pushed a commit to LubanCat/kernel that referenced this issue Dec 14, 2022
With RT_FULL we get the below wreckage:

[  126.060484] =======================================================
[  126.060486] [ INFO: possible circular locking dependency detected ]
[  126.060489] 3.0.1-rt10+ rockchip-linux#30
[  126.060490] -------------------------------------------------------
[  126.060492] irq/24-eth0/1235 is trying to acquire lock:
[  126.060495]  (&(lock)->wait_lock#2){+.+...}, at: [<ffffffff81501c81>] rt_mutex_slowunlock+0x16/0x55
[  126.060503]
[  126.060504] but task is already holding lock:
[  126.060506]  (&p->pi_lock){-...-.}, at: [<ffffffff81074fdc>] try_to_wake_up+0x35/0x429
[  126.060511]
[  126.060511] which lock already depends on the new lock.
[  126.060513]
[  126.060514]
[  126.060514] the existing dependency chain (in reverse order) is:
[  126.060516]
[  126.060516] -> #1 (&p->pi_lock){-...-.}:
[  126.060519]        [<ffffffff810afe9e>] lock_acquire+0x145/0x18a
[  126.060524]        [<ffffffff8150291e>] _raw_spin_lock_irqsave+0x4b/0x85
[  126.060527]        [<ffffffff810b5aa4>] task_blocks_on_rt_mutex+0x36/0x20f
[  126.060531]        [<ffffffff815019bb>] rt_mutex_slowlock+0xd1/0x15a
[  126.060534]        [<ffffffff81501ae3>] rt_mutex_lock+0x2d/0x2f
[  126.060537]        [<ffffffff810d9020>] rcu_boost+0xad/0xde
[  126.060541]        [<ffffffff810d90ce>] rcu_boost_kthread+0x7d/0x9b
[  126.060544]        [<ffffffff8109a760>] kthread+0x99/0xa1
[  126.060547]        [<ffffffff81509b14>] kernel_thread_helper+0x4/0x10
[  126.060551]
[  126.060552] -> #0 (&(lock)->wait_lock#2){+.+...}:
[  126.060555]        [<ffffffff810af1b8>] __lock_acquire+0x1157/0x1816
[  126.060558]        [<ffffffff810afe9e>] lock_acquire+0x145/0x18a
[  126.060561]        [<ffffffff8150279e>] _raw_spin_lock+0x40/0x73
[  126.060564]        [<ffffffff81501c81>] rt_mutex_slowunlock+0x16/0x55
[  126.060566]        [<ffffffff81501ce7>] rt_mutex_unlock+0x27/0x29
[  126.060569]        [<ffffffff810d9f86>] rcu_read_unlock_special+0x17e/0x1c4
[  126.060573]        [<ffffffff810da014>] __rcu_read_unlock+0x48/0x89
[  126.060576]        [<ffffffff8106847a>] select_task_rq_rt+0xc7/0xd5
[  126.060580]        [<ffffffff8107511c>] try_to_wake_up+0x175/0x429
[  126.060583]        [<ffffffff81075425>] wake_up_process+0x15/0x17
[  126.060585]        [<ffffffff81080a51>] wakeup_softirqd+0x24/0x26
[  126.060590]        [<ffffffff81081df9>] irq_exit+0x49/0x55
[  126.060593]        [<ffffffff8150a3bd>] smp_apic_timer_interrupt+0x8a/0x98
[  126.060597]        [<ffffffff81509793>] apic_timer_interrupt+0x13/0x20
[  126.060600]        [<ffffffff810d5952>] irq_forced_thread_fn+0x1b/0x44
[  126.060603]        [<ffffffff810d582c>] irq_thread+0xde/0x1af
[  126.060606]        [<ffffffff8109a760>] kthread+0x99/0xa1
[  126.060608]        [<ffffffff81509b14>] kernel_thread_helper+0x4/0x10
[  126.060611]
[  126.060612] other info that might help us debug this:
[  126.060614]
[  126.060615]  Possible unsafe locking scenario:
[  126.060616]
[  126.060617]        CPU0                    CPU1
[  126.060619]        ----                    ----
[  126.060620]   lock(&p->pi_lock);
[  126.060623]                                lock(&(lock)->wait_lock);
[  126.060625]                                lock(&p->pi_lock);
[  126.060627]   lock(&(lock)->wait_lock);
[  126.060629]
[  126.060629]  *** DEADLOCK ***
[  126.060630]
[  126.060632] 1 lock held by irq/24-eth0/1235:
[  126.060633]  #0:  (&p->pi_lock){-...-.}, at: [<ffffffff81074fdc>] try_to_wake_up+0x35/0x429
[  126.060638]
[  126.060638] stack backtrace:
[  126.060641] Pid: 1235, comm: irq/24-eth0 Not tainted 3.0.1-rt10+ rockchip-linux#30
[  126.060643] Call Trace:
[  126.060644]  <IRQ>  [<ffffffff810acbde>] print_circular_bug+0x289/0x29a
[  126.060651]  [<ffffffff810af1b8>] __lock_acquire+0x1157/0x1816
[  126.060655]  [<ffffffff810ab3aa>] ? trace_hardirqs_off_caller+0x1f/0x99
[  126.060658]  [<ffffffff81501c81>] ? rt_mutex_slowunlock+0x16/0x55
[  126.060661]  [<ffffffff810afe9e>] lock_acquire+0x145/0x18a
[  126.060664]  [<ffffffff81501c81>] ? rt_mutex_slowunlock+0x16/0x55
[  126.060668]  [<ffffffff8150279e>] _raw_spin_lock+0x40/0x73
[  126.060671]  [<ffffffff81501c81>] ? rt_mutex_slowunlock+0x16/0x55
[  126.060674]  [<ffffffff810d9655>] ? rcu_report_qs_rsp+0x87/0x8c
[  126.060677]  [<ffffffff81501c81>] rt_mutex_slowunlock+0x16/0x55
[  126.060680]  [<ffffffff810d9ea3>] ? rcu_read_unlock_special+0x9b/0x1c4
[  126.060683]  [<ffffffff81501ce7>] rt_mutex_unlock+0x27/0x29
[  126.060687]  [<ffffffff810d9f86>] rcu_read_unlock_special+0x17e/0x1c4
[  126.060690]  [<ffffffff810da014>] __rcu_read_unlock+0x48/0x89
[  126.060693]  [<ffffffff8106847a>] select_task_rq_rt+0xc7/0xd5
[  126.060696]  [<ffffffff810683da>] ? select_task_rq_rt+0x27/0xd5
[  126.060701]  [<ffffffff810a852a>] ? clockevents_program_event+0x8e/0x90
[  126.060704]  [<ffffffff8107511c>] try_to_wake_up+0x175/0x429
[  126.060708]  [<ffffffff810a95dc>] ? tick_program_event+0x1f/0x21
[  126.060711]  [<ffffffff81075425>] wake_up_process+0x15/0x17
[  126.060715]  [<ffffffff81080a51>] wakeup_softirqd+0x24/0x26
[  126.060718]  [<ffffffff81081df9>] irq_exit+0x49/0x55
[  126.060721]  [<ffffffff8150a3bd>] smp_apic_timer_interrupt+0x8a/0x98
[  126.060724]  [<ffffffff81509793>] apic_timer_interrupt+0x13/0x20
[  126.060726]  <EOI>  [<ffffffff81072855>] ? migrate_disable+0x75/0x12d
[  126.060733]  [<ffffffff81080a61>] ? local_bh_disable+0xe/0x1f
[  126.060736]  [<ffffffff81080a70>] ? local_bh_disable+0x1d/0x1f
[  126.060739]  [<ffffffff810d5952>] irq_forced_thread_fn+0x1b/0x44
[  126.060742]  [<ffffffff81502ac0>] ? _raw_spin_unlock_irq+0x3b/0x59
[  126.060745]  [<ffffffff810d582c>] irq_thread+0xde/0x1af
[  126.060748]  [<ffffffff810d5937>] ? irq_thread_fn+0x3a/0x3a
[  126.060751]  [<ffffffff810d574e>] ? irq_finalize_oneshot+0xd1/0xd1
[  126.060754]  [<ffffffff810d574e>] ? irq_finalize_oneshot+0xd1/0xd1
[  126.060757]  [<ffffffff8109a760>] kthread+0x99/0xa1
[  126.060761]  [<ffffffff81509b14>] kernel_thread_helper+0x4/0x10
[  126.060764]  [<ffffffff81069ed7>] ? finish_task_switch+0x87/0x10a
[  126.060768]  [<ffffffff81502ec4>] ? retint_restore_args+0xe/0xe
[  126.060771]  [<ffffffff8109a6c7>] ? __init_kthread_worker+0x8c/0x8c
[  126.060774]  [<ffffffff81509b10>] ? gs_change+0xb/0xb

Because irq_exit() does:

void irq_exit(void)
{
	account_system_vtime(current);
	trace_hardirq_exit();
	sub_preempt_count(IRQ_EXIT_OFFSET);
	if (!in_interrupt() && local_softirq_pending())
		invoke_softirq();

	...
}

Which triggers a wakeup, which uses RCU, now if the interrupted task has
t->rcu_read_unlock_special set, the rcu usage from the wakeup will end
up in rcu_read_unlock_special(). rcu_read_unlock_special() will test
for in_irq(), which will fail as we just decremented preempt_count
with IRQ_EXIT_OFFSET, and in_sering_softirq(), which for
PREEMPT_RT_FULL reads:

int in_serving_softirq(void)
{
	int res;

	preempt_disable();
	res = __get_cpu_var(local_softirq_runner) == current;
	preempt_enable();
	return res;
}

Which will thus also fail, resulting in the above wreckage.

The 'somewhat' ugly solution is to open-code the preempt_count() test
in rcu_read_unlock_special().

Also, we're not at all sure how ->rcu_read_unlock_special gets set
here... so this is very likely a bandaid and more thought is required.

Cc: Paul E. McKenney <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
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