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Commit 9efade1b authored by Jussi Kivilinna's avatar Jussi Kivilinna Committed by Herbert Xu
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crypto: cryptd - disable softirqs in cryptd_queue_worker to prevent data corruption 

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: default avatarGurucharan Shetty <gurucharan.shetty@gmail.com>
Signed-off-by: default avatarJussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent ddffeb8c

crypto/cryptd.c

+8 −3
Original line number Original line Diff line number Diff line
@@ -137,13 +137,18 @@ static void cryptd_queue_worker(struct work_struct *work) 
	struct crypto_async_request *req, *backlog;

	struct crypto_async_request *req, *backlog;





	cpu_queue = container_of(work, struct cryptd_cpu_queue, work);

	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

	 * Only handle one request at a time to avoid hogging crypto workqueue.

	 * being preempted by cryptd_enqueue_request() */

	 * 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();

	preempt_disable();

	backlog = crypto_get_backlog(&cpu_queue->queue);

	backlog = crypto_get_backlog(&cpu_queue->queue);

	req = crypto_dequeue_request(&cpu_queue->queue);

	req = crypto_dequeue_request(&cpu_queue->queue);

	preempt_enable();

	preempt_enable();

	local_bh_enable();





	if (!req)

	if (!req)

		return;

		return;