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authorJussi Kivilinna <jussi.kivilinna@mbnet.fi>2012-10-21 20:42:28 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-11-26 11:34:33 -0800
commit8493a233c5ef25d64ed2d84e4b14c4ca45929708 (patch)
treeb41d63bf9aebe7febf394fb02247bb102fb598f7
parent5a5ffbe9623739953af7cbec40ae8d33472cb638 (diff)
crypto: cryptd - disable softirqs in cryptd_queue_worker to prevent data corruption
commit 9efade1b3e981f5064f9db9ca971b4dc7557ae42 upstream. 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 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--crypto/cryptd.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/crypto/cryptd.c b/crypto/cryptd.c
index 671d4d6d14df..7bdd61b867c8 100644
--- a/crypto/cryptd.c
+++ b/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;