[1/2] crypto: algif_hash - Fix race condition in hash_check_key
diff mbox series

Message ID 20160114141528.GA21348@gondor.apana.org.au
State New, archived
Headers show
Series
  • crypto: Fix race condition in *_check_key
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Commit Message

Herbert Xu Jan. 14, 2016, 2:15 p.m. UTC
We need to lock the child socket in hash_check_key as otherwise
two simultaneous calls can cause the parent socket to be freed.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Patch
diff mbox series

diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c
index 46637be..598f141 100644
--- a/crypto/algif_hash.c
+++ b/crypto/algif_hash.c
@@ -242,15 +242,16 @@  static struct proto_ops algif_hash_ops = {
 
 static int hash_check_key(struct socket *sock)
 {
-	int err;
+	int err = 0;
 	struct sock *psk;
 	struct alg_sock *pask;
 	struct algif_hash_tfm *tfm;
 	struct sock *sk = sock->sk;
 	struct alg_sock *ask = alg_sk(sk);
 
+	lock_sock(sk);
 	if (ask->refcnt)
-		return 0;
+		goto unlock_child;
 
 	psk = ask->parent;
 	pask = alg_sk(ask->parent);
@@ -271,6 +272,8 @@  static int hash_check_key(struct socket *sock)
 
 unlock:
 	release_sock(psk);
+unlock_child:
+	release_sock(sk);
 
 	return err;
 }