[PATCH 4/4] crypto: af_alg - Forbid bind(2) when nokey child sockets are present
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: 2016-01-13 07:03:40
Also in:
lkml
Subsystem:
crypto api, the rest · Maintainers:
Herbert Xu, "David S. Miller", Linus Torvalds
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 <herbert@gondor.apana.org.au>
diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index e7cb836..f5e18c2 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;
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt