crypto: cryptd - disable softirqs in cryptd_queue_worker to prevent data corruption (9efade1b) · Commits · 戴 / test

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 <gurucharan.shetty@gmail.com> Signed-off-by:

Jussi Kivilinna <jussi.kivilinna@mbnet.fi> Signed-off-by:

Herbert Xu <herbert@gondor.apana.org.au>

crypto/cryptd.c

+8 −3

Original line number	Diff line number	Diff line
		@@ -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;

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