linux-kernel - [ 04/38] crypto: cryptd - disable softirqs in cryptd_queue

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Date:	Wed, 21 Nov 2012 16:39:47 -0800
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	alan@...rguk.ukuu.org.uk,
	Gurucharan Shetty <gurucharan.shetty@...il.com>,
	Jussi Kivilinna <jussi.kivilinna@...et.fi>,
	Herbert Xu <herbert@...dor.apana.org.au>
Subject: [ 04/38] crypto: cryptd - disable softirqs in cryptd_queue_worker to prevent data corruption

3.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jussi Kivilinna <jussi.kivilinna@...et.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@...il.com>
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@...et.fi>
Signed-off-by: Herbert Xu <herbert@...dor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 crypto/cryptd.c |   11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

--- a/crypto/cryptd.c
+++ b/crypto/cryptd.c
@@ -137,13 +137,18 @@ static void cryptd_queue_worker(struct w
 	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;


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/