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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: 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>
master
Jussi Kivilinna 9 years ago
committed by Herbert Xu
parent
commit
9efade1b3e
  1. 11
      crypto/cryptd.c

11
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;

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