btrfs: prevent NULL pointer dereference in extent_io_tree_panic

Some extent io trees are initialized with NULL private member (e.g. btrfs_device::alloc_state and btrfs_fs_info::excluded_extents). Dereference of a NULL tree->private as inode pointer will cause panic. Pass tree->fs_info as it's known to be valid in all cases. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=208929 Fixes: 05912a3 ("btrfs: drop extent_io_ops::tree_fs_info callback") CC: [email protected] # 4.19+ Reviewed-by: Anand Jain <[email protected]> Signed-off-by: Su Yue <[email protected]> Reviewed-by: David Sterba <[email protected]> Signed-off-by: David Sterba <[email protected]>
vchong · Jan 7, 2021 · 29b665c · 29b665c
1 parent 7100873
commit 29b665c
Showing 1 changed file with 1 addition and 3 deletions.
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
@@ -676,9 +676,7 @@ alloc_extent_state_atomic(struct extent_state *prealloc)
 
 static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
 {
-	struct inode *inode = tree->private_data;
-
-	btrfs_panic(btrfs_sb(inode->i_sb), err,
+	btrfs_panic(tree->fs_info, err,
 	"locking error: extent tree was modified by another thread while locked");
 }