From: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxxxxxxxxxx
Reported-by: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Fixes: c840ac6af3f8 ("crypto: af_alg - Disallow bind/setkey/...")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
crypto/af_alg.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -136,11 +136,13 @@ void af_alg_release_parent(struct sock *
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);
