From: Jussi Kivilinna Subject: [PATCH] [v2] crypto: cryptd - disable softirqs in cryptd_queue_worker to prevent data corruption Date: Sun, 21 Oct 2012 20:42:28 +0300 Message-ID: <20121021174228.9770.3775.stgit@localhost6.localdomain6> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: Gurucharan Shetty , Herbert Xu , stable@vger.kernel.org, "David S. Miller" To: linux-crypto@vger.kernel.org Return-path: Received: from sd-mail-sa-01.sanoma.fi ([158.127.18.161]:36337 "EHLO sd-mail-sa-01.sanoma.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932303Ab2JURmb (ORCPT ); Sun, 21 Oct 2012 13:42:31 -0400 Sender: linux-crypto-owner@vger.kernel.org List-ID: cryptd_queue_worker attempts to prevent simultaneous accesses to crypto workqueue by cryptd_enqueue_request using preempt_disable/preempt_enable. However cryptd_enqueue_request might be called from softirq context, so add local_bh_disable/local_bh_enable to prevent data corruption and panics. Bug report at http://marc.info/?l=linux-crypto-vger&m=134858649616319&w=2 v2: - Disable software interrupts instead of hardware interrupts Cc: stable@vger.kernel.org Reported-by: Gurucharan Shetty Signed-off-by: Jussi Kivilinna --- crypto/cryptd.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/crypto/cryptd.c b/crypto/cryptd.c index 671d4d6..7bdd61b 100644 --- a/crypto/cryptd.c +++ b/crypto/cryptd.c @@ -137,13 +137,18 @@ static void cryptd_queue_worker(struct work_struct *work) struct crypto_async_request *req, *backlog; cpu_queue = container_of(work, struct cryptd_cpu_queue, work); - /* Only handle one request at a time to avoid hogging crypto - * workqueue. preempt_disable/enable is used to prevent - * being preempted by cryptd_enqueue_request() */ + /* + * Only handle one request at a time to avoid hogging crypto workqueue. + * preempt_disable/enable is used to prevent being preempted by + * cryptd_enqueue_request(). local_bh_disable/enable is used to prevent + * cryptd_enqueue_request() being accessed from software interrupts. + */ + local_bh_disable(); preempt_disable(); backlog = crypto_get_backlog(&cpu_queue->queue); req = crypto_dequeue_request(&cpu_queue->queue); preempt_enable(); + local_bh_enable(); if (!req) return;