From e118ea0bf030f9a6e1bce7d1f0399410c0ffb80e Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Wed, 13 Jan 2016 15:03:32 +0800 Subject: [PATCH] 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 --- 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 e7cb8367771df..f5e18c2a48527 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) @@ -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; -- 2.39.5