| From | Herton Ronaldo Krzesinski <> | Subject | [PATCH 047/241] crypto: cryptd - disable softirqs in cryptd_queue_worker to prevent data corruption | Date | Thu, 13 Dec 2012 11:56:52 -0200 |
| |
3.5.7.2 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
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: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> --- crypto/cryptd.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/crypto/cryptd.c b/crypto/cryptd.c index 671d4d6..7bdd61b 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; -- 1.7.9.5
|