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| author | Jussi Kivilinna <jussi.kivilinna@mbnet.fi> | 2012-10-21 20:42:28 +0300 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2012-11-16 16:46:55 +0000 |
| commit | 6ae9425d0d643c68945b7772c6adf3ea1f40e864 (patch) | |
| tree | 75a9485c6c69747db3a3a3835f3ddc3cc1037030 /crypto | |
| parent | 7381ef4c90bd96b8fa02b28077eb657a154ba156 (diff) | |
| download | lwn-6ae9425d0d643c68945b7772c6adf3ea1f40e864.tar.gz lwn-6ae9425d0d643c68945b7772c6adf3ea1f40e864.zip | |
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: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/cryptd.c | 11 |
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; |