From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755370Ab3IYAMU (ORCPT ); Tue, 24 Sep 2013 20:12:20 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:38538 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755342Ab3IYAMQ (ORCPT ); Tue, 24 Sep 2013 20:12:16 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kees Cook , Herbert Xu Subject: [ 02/40] crypto: api - Fix race condition in larval lookup Date: Tue, 24 Sep 2013 17:11:34 -0700 Message-Id: <20130925001042.235645066@linuxfoundation.org> X-Mailer: git-send-email 1.8.4.3.gca3854a In-Reply-To: <20130925001041.939335518@linuxfoundation.org> References: <20130925001041.939335518@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Herbert Xu commit 77dbd7a95e4a4f15264c333a9e9ab97ee27dc2aa upstream. 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. Reported-by: Kees Cook Tested-by: Kees Cook Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- crypto/api.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/crypto/api.c +++ b/crypto/api.c @@ -40,6 +40,8 @@ static inline struct crypto_alg *crypto_ 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_ } 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; }