sock_map: Add a cond_resched() in sock_hash_free()

edumazet · gregkh · commit 80bd490ac0a3 · 2024-10-04T16:28:58.000+02:00
[ Upstream commit b1339be ] Several syzbot soft lockup reports all have in common sock_hash_free() If a map with a large number of buckets is destroyed, we need to yield the cpu when needed. Fixes: 75e68e5 ("bpf, sockhash: Synchronize delete from bucket list on map free") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <martin.lau@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20240906154449.3742932-1-edumazet@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/net/core/sock_map.c b/net/core/sock_map.c
@@ -1171,6 +1171,7 @@ static void sock_hash_free(struct bpf_map *map)
 			sock_put(elem->sk);
 			sock_hash_free_elem(htab, elem);
 		}
+		cond_resched();
 	}
 
 	/* wait for psock readers accessing its map link */

Original file line number	Diff line number	Diff line change
`@@ -1171,6 +1171,7 @@ static void sock_hash_free(struct bpf_map *map)`
`1171`	`1171`	`sock_put(elem->sk);`
`1172`	`1172`	`sock_hash_free_elem(htab, elem);`
`1173`	`1173`	`}`
	`1174`	`+ cond_resched();`
`1174`	`1175`	`}`
`1175`	`1176`
`1176`	`1177`	`/* wait for psock readers accessing its map link */`