From: Alexey Khoroshilov <khoroshilov@ispras.ru>
Date: Mon, 29 Aug 2011 17:46:57 +0000 (+0400)
Subject: staging/easycap: fix mismatch in easycap_poll() mutex lock-unlock
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=22f88fcf407933321d08c45520fbeffca70b05d1;p=linux-beck.git

staging/easycap: fix mismatch in easycap_poll() mutex lock-unlock

In case if condition (kd != isdongle(peasycap)) becomes true,
easycap_poll() returns without releasing easycapdc60_dongle[kd].mutex_video.
The patch adds mutex_unlock() before that return.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/staging/easycap/easycap_main.c b/drivers/staging/easycap/easycap_main.c
index bea281624c41..3ea51c373914 100644
--- a/drivers/staging/easycap/easycap_main.c
+++ b/drivers/staging/easycap/easycap_main.c
@@ -953,8 +953,10 @@ static unsigned int easycap_poll(struct file *file, poll_table *wait)
 	 *  peasycap, IN WHICH CASE A REPEAT CALL TO isdongle() WILL FAIL.
 	 *  IF NECESSARY, BAIL OUT.
 	 */
-		if (kd != isdongle(peasycap))
+		if (kd != isdongle(peasycap)) {
+			mutex_unlock(&easycapdc60_dongle[kd].mutex_video);
 			return -ERESTARTSYS;
+		}
 		if (!file) {
 			SAY("ERROR:  file is NULL\n");
 			mutex_unlock(&easycapdc60_dongle[kd].mutex_video);