| From e28f64b152d9505a54fb2bb89dd4527ac2f4599a Mon Sep 17 00:00:00 2001 |
| From: Jussi Kivilinna <jussi.kivilinna@mbnet.fi> |
| Date: Sun, 21 Oct 2012 20:42:28 +0300 |
| Subject: [PATCH] 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: 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 |
| |
