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authorHerbert Xu <herbert@gondor.apana.org.au>2016-01-15 17:02:20 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-02-20 01:28:36 +0300
commit379b8645fcb1f8cb89959c4f4bc122617107698f (patch)
treea4478e99cafe8df68a06f86788dec201da98ee22
parent9b1f316a4af707548bd6519081557c4f1a5bf12f (diff)
downloadlinux-379b8645fcb1f8cb89959c4f4bc122617107698f.tar.xz
crypto: algif_skcipher - Fix race condition in skcipher_check_key
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 <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--crypto/algif_skcipher.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index 572a92704e38..e3e9e132d2b2 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -755,22 +755,23 @@ 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;
@@ -784,6 +785,8 @@ static int skcipher_check_key(struct socket *sock)
unlock:
release_sock(psk);
+unlock_child:
+ release_sock(sk);
return err;
}