[PATCH] crypto: cryptd - disable interrupts in cryptd_queue_worker to prevent data corruption
From: Jussi Kivilinna <hidden>
Date: 2012-10-20 09:13:19
Subsystem:
crypto api, the rest · Maintainers:
Herbert Xu, "David S. Miller", Linus Torvalds
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 <redacted> Tested-by: Gurucharan Shetty <redacted> Signed-off-by: Jussi Kivilinna <redacted> --- 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)