| From | Paul Gortmaker <> | Subject | [v2.6.34-stable 126/213] crypto: cryptd - disable softirqs in cryptd_queue_worker to prevent data corruption | Date | Wed, 5 Feb 2014 15:01:21 -0500 |
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From: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. -------------------
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: Paul Gortmaker <paul.gortmaker@windriver.com> --- crypto/cryptd.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/crypto/cryptd.c b/crypto/cryptd.c index ef71318976c7..6e241640219d 100644 --- a/crypto/cryptd.c +++ b/crypto/cryptd.c @@ -116,13 +116,18 @@ 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; -- 1.8.5.2
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