netfilter: nf_tables: disable preemption in nft_update_chain_stats()

commit ad9d9e8 upstream. This patch fixes the following splat. [118709.054937] BUG: using smp_processor_id() in preemptible [00000000] code: test/1571 [118709.054970] caller is nft_update_chain_stats.isra.4+0x53/0x97 [nf_tables] [118709.054980] CPU: 2 PID: 1571 Comm: test Not tainted 4.17.0-rc6+ #335 [...] [118709.054992] Call Trace: [118709.055011] dump_stack+0x5f/0x86 [118709.055026] check_preemption_disabled+0xd4/0xe4 Signed-off-by: Pablo Neira Ayuso <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
raspberrypi · Jul 8, 2018 · d3a9b8a · d3a9b8a
1 parent 491b1a8
commit d3a9b8a
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c
@@ -126,15 +126,15 @@ static noinline void nft_update_chain_stats(const struct nft_chain *chain,
 	if (!base_chain->stats)
 		return;
 
+	local_bh_disable();
 	stats = this_cpu_ptr(rcu_dereference(base_chain->stats));
 	if (stats) {
-		local_bh_disable();
 		u64_stats_update_begin(&stats->syncp);
 		stats->pkts++;
 		stats->bytes += pkt->skb->len;
 		u64_stats_update_end(&stats->syncp);
-		local_bh_enable();
 	}
+	local_bh_enable();
 }
 
 struct nft_jumpstack {