From 88dd6606685b44773613be5b9bef2dfe5bf5d601 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 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. Signed-off-by: Herbert Xu Signed-off-by: Luis Henriques --- 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 d86ef339d8cb..30c1ae491fd4 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;