From fb0b50cf872a56be4e216d0ec8a1ff506ff879d9 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Thu, 27 Oct 2016 17:29:45 +0300 Subject: [PATCH] crypto: af_alg - Forbid bind(2) when nokey child sockets are present commit a6a48c565f6f112c6983e2a02b1602189ed6e26e upstream. 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 Signed-off-by: Andrey Ryabinin Signed-off-by: Willy Tarreau --- crypto/af_alg.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/crypto/af_alg.c b/crypto/af_alg.c index 2f8fd8441f34..68ec1ac4104a 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -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) @@ -185,7 +182,7 @@ 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); @@ -296,6 +293,7 @@ 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; -- 2.20.1