From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758616AbaELC0N (ORCPT ); Sun, 11 May 2014 22:26:13 -0400 Received: from 1wt.eu ([62.212.114.60]:34355 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750822AbaELBlc (ORCPT ); Sun, 11 May 2014 21:41:32 -0400 Message-Id: <20140512003201.673375440@1wt.eu> User-Agent: quilt/0.48-1 Date: Mon, 12 May 2014 02:32:25 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Herbert Xu , Nikola Pajkovsky , Willy Tarreau Subject: [ 025/143] crypto: api - Fix race condition in larval lookup In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Nikola Pajkovsky https://bugzilla.redhat.com/1016108 64z is missing rhel6 commit 3af031a395c0 ("[crypto] algboss: Hold ref count on larval") which is causing cosmetic fuzz, because crypto_alg_get was move from crypto/api.c to crypto/internal.h. From: Herbert Xu [ upstream commit 77dbd7a95e4a4f15264c333a9e9ab97ee27dc2aa ] crypto_larval_lookup should only return a larval if it created one. Any larval created by another entity must be processed through crypto_larval_wait before being returned. Otherwise this will lead to a larval being killed twice, which will most likely lead to a crash. Cc: stable@vger.kernel.org Reported-by: Kees Cook Tested-by: Kees Cook Signed-off-by: Herbert Xu Signed-off-by: Nikola Pajkovsky Signed-off-by: Willy Tarreau --- crypto/api.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/crypto/api.c b/crypto/api.c index 798526d..f4be65f 100644 --- a/crypto/api.c +++ b/crypto/api.c @@ -40,6 +40,8 @@ static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg) return alg; } +static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg); + struct crypto_alg *crypto_mod_get(struct crypto_alg *alg) { return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL; @@ -150,8 +152,11 @@ static struct crypto_alg *crypto_larval_add(const char *name, u32 type, } up_write(&crypto_alg_sem); - if (alg != &larval->alg) + if (alg != &larval->alg) { kfree(larval); + if (crypto_is_larval(alg)) + alg = crypto_larval_wait(alg); + } return alg; } -- 1.7.12.2.21.g234cd45.dirty