crypto: af_alg - Forbid bind(2) when nokey child sockets are present

This patch forbids the calling of bind(2) when there are child
sockets created by accept(2) in existence, even if they are created
on the nokey path.

This is needed as those child sockets have references to the tfm
object which bind(2) will destroy.

Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Herbert Xu 2016-01-13 15:03:32 +08:00
parent d7b65aee1e
commit a6a48c565f

View File

@ -130,19 +130,16 @@ EXPORT_SYMBOL_GPL(af_alg_release);
void af_alg_release_parent(struct sock *sk)
{
struct alg_sock *ask = alg_sk(sk);
bool last;
unsigned int nokey = ask->nokey_refcnt;
bool last = nokey && !ask->refcnt;
sk = ask->parent;
if (ask->nokey_refcnt && !ask->refcnt) {
sock_put(sk);
return;
}
ask = alg_sk(sk);
lock_sock(sk);
last = !--ask->refcnt;
ask->nokey_refcnt -= nokey;
if (!last)
last = !--ask->refcnt;
release_sock(sk);
if (last)
@ -188,7 +185,7 @@ static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
err = -EBUSY;
lock_sock(sk);
if (ask->refcnt)
if (ask->refcnt | ask->nokey_refcnt)
goto unlock;
swap(ask->type, type);
@ -306,6 +303,7 @@ int af_alg_accept(struct sock *sk, struct socket *newsock)
if (nokey || !ask->refcnt++)
sock_hold(sk);
ask->nokey_refcnt += nokey;
alg_sk(sk2)->parent = sk;
alg_sk(sk2)->type = type;
alg_sk(sk2)->nokey_refcnt = nokey;