From: Jussi Kivilinna Subject: [PATCH] crypto: cryptd - disable interrupts in cryptd_queue_worker to prevent data corruption Date: Sat, 20 Oct 2012 12:13:14 +0300 Message-ID: <20121020091314.32511.49390.stgit@localhost6.localdomain6> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: stable@kernel.org, Gurucharan Shetty , Herbert Xu , "David S. Miller" To: linux-crypto@vger.kernel.org Return-path: Received: from sd-mail-sa-02.sanoma.fi ([158.127.18.162]:57792 "EHLO sd-mail-sa-02.sanoma.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753868Ab2JTJNT (ORCPT ); Sat, 20 Oct 2012 05:13:19 -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 interrupt context, so add local_irq_save/local_irq_restore to prevent data corruption and panics. Bug report at http://marc.info/?l=linux-crypto-vger&m=134858649616319&w=2 Cc: stable@kernel.org Reported-by: Gurucharan Shetty Tested-by: Gurucharan Shetty Signed-off-by: Jussi Kivilinna --- crypto/cryptd.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/crypto/cryptd.c b/crypto/cryptd.c index 671d4d6..8f62d06 100644 --- a/crypto/cryptd.c +++ b/crypto/cryptd.c @@ -133,16 +133,23 @@ static int cryptd_enqueue_request(struct cryptd_queue *queue, * do. */ static void cryptd_queue_worker(struct work_struct *work) { + unsigned long flags; struct cryptd_cpu_queue *cpu_queue; 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 + /* + * 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() */ + * being preempted by cryptd_enqueue_request(). local_irq_save/restore + * is used to prevent cryptd_enqueue_request() being accessed from + * interrupts. + */ + local_irq_save(flags); preempt_disable(); backlog = crypto_get_backlog(&cpu_queue->queue); req = crypto_dequeue_request(&cpu_queue->queue); + local_irq_restore(flags); preempt_enable(); if (!req)