3.19.8-ckt18 -stable review patch.  If anyone has any objections, please let me 
know.

---8<------------------------------------------------------------

From: Herbert Xu <herb...@gondor.apana.org.au>

commit 1822793a523e5d5730b19cc21160ff1717421bc8 upstream.

We need to lock the child socket in skcipher_check_key as otherwise
two simultaneous calls can cause the parent socket to be freed.

Signed-off-by: Herbert Xu <herb...@gondor.apana.org.au>
Signed-off-by: Kamal Mostafa <ka...@canonical.com>
---
 crypto/algif_skcipher.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index 68caee1..974bfd2 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -548,22 +548,23 @@ static struct proto_ops algif_skcipher_ops = {
 
 static int skcipher_check_key(struct socket *sock)
 {
-       int err;
+       int err = 0;
        struct sock *psk;
        struct alg_sock *pask;
        struct skcipher_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);
        tfm = pask->private;
 
        err = -ENOKEY;
-       lock_sock(psk);
+       lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
        if (!tfm->has_key)
                goto unlock;
 
@@ -577,6 +578,8 @@ static int skcipher_check_key(struct socket *sock)
 
 unlock:
        release_sock(psk);
+unlock_child:
+       release_sock(sk);
 
        return err;
 }
-- 
2.7.4

Reply via email to