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| author | Herbert Xu <herbert@gondor.apana.org.au> | 2016-01-15 22:01:08 +0800 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2016-02-13 10:34:13 +0000 |
| commit | 8d33fff4858afd802c90da36e2020641b1a9599b (patch) | |
| tree | ac4e3016b60fbe45302e3d5eed57d10ce0ccd2b4 | |
| parent | f1cf0b97e71d91b2b9d68540265133eb7711d3ed (diff) | |
| download | lwn-8d33fff4858afd802c90da36e2020641b1a9599b.tar.gz lwn-8d33fff4858afd802c90da36e2020641b1a9599b.zip | |
crypto: algif_hash - Fix race condition in hash_check_key
commit ad46d7e33219218605ea619e32553daf4f346b9f upstream.
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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | crypto/algif_hash.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c index 287e3fe08428..2dfb0f10e0bb 100644 --- a/crypto/algif_hash.c +++ b/crypto/algif_hash.c @@ -253,22 +253,23 @@ 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); tfm = pask->private; err = -ENOKEY; - lock_sock(psk); + lock_sock_nested(psk, SINGLE_DEPTH_NESTING); if (!tfm->has_key) goto unlock; @@ -282,6 +283,8 @@ static int hash_check_key(struct socket *sock) unlock: release_sock(psk); +unlock_child: + release_sock(sk); return err; } |