crypto: af_alg - Use bh_lock_sock in sk_destruct

commit 37f96694cf73ba116993a9d2d99ad6a75fa7fdb0 upstream.

As af_alg_release_parent may be called from BH context (most notably
due to an async request that only completes after socket closure,
or as reported here because of an RCU-delayed sk_destruct call), we
must use bh_lock_sock instead of lock_sock.

Reported-by: syzbot+c2f1558d49e25cc36e5e@syzkaller.appspotmail.com
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: c840ac6af3 ("crypto: af_alg - Disallow bind/setkey/...")
Cc: <stable@vger.kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Herbert Xu 2019-12-05 13:45:05 +08:00 committed by Greg Kroah-Hartman
parent 5c1187d168
commit 6b544caa07

View File

@ -139,11 +139,13 @@ void af_alg_release_parent(struct sock *sk)
sk = ask->parent;
ask = alg_sk(sk);
lock_sock(sk);
local_bh_disable();
bh_lock_sock(sk);
ask->nokey_refcnt -= nokey;
if (!last)
last = !--ask->refcnt;
release_sock(sk);
bh_unlock_sock(sk);
local_bh_enable();
if (last)
sock_put(sk);