diff mbox

media: em28xx: Don't use ops->resume if NULL

Message ID 875ca4eae7623e3f54acb2fd364404491b78951d.1524481357.git.mchehab@s-opensource.com (mailing list archive)
State New, archived
Headers show

Commit Message

Mauro Carvalho Chehab April 23, 2018, 11:02 a.m. UTC 
Changeset  be7fd3c3a8c5 ("media: em28xx: Hauppauge DualHD
second tuner functionality") introduced a potential NULL pointer
dereference, as pointed by Coverity:

CID 1434731 (#1 of 1): Dereference after null check (FORWARD_NULL)16. var_deref_op: Dereferencing null pointer ops->resume.

var_compare_op: Comparing ops->resume to null implies that ops->resume might be null.
1174                if (ops->resume)
1175                        ops->resume(dev);
1176                if (dev->dev_next)
1177                        ops->resume(dev->dev_next);

Fixes: be7fd3c3a8c5 ("media: em28xx: Hauppauge DualHD second tuner functionality")
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
---
 drivers/media/usb/em28xx/em28xx-core.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Sakari Ailus April 24, 2018, 10:08 a.m. UTC | #1 
On Mon, Apr 23, 2018 at 07:02:39AM -0400, Mauro Carvalho Chehab wrote:
> Changeset  be7fd3c3a8c5 ("media: em28xx: Hauppauge DualHD
> second tuner functionality") introduced a potential NULL pointer
> dereference, as pointed by Coverity:
> 
> CID 1434731 (#1 of 1): Dereference after null check (FORWARD_NULL)16. var_deref_op: Dereferencing null pointer ops->resume.
> 
> var_compare_op: Comparing ops->resume to null implies that ops->resume might be null.
> 1174                if (ops->resume)
> 1175                        ops->resume(dev);
> 1176                if (dev->dev_next)
> 1177                        ops->resume(dev->dev_next);
> 
> Fixes: be7fd3c3a8c5 ("media: em28xx: Hauppauge DualHD second tuner functionality")
> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
diff mbox

Patch

diff --git a/drivers/media/usb/em28xx/em28xx-core.c b/drivers/media/usb/em28xx/em28xx-core.c
index 36d341fb65dd..0cefd29184f6 100644
--- a/drivers/media/usb/em28xx/em28xx-core.c
+++ b/drivers/media/usb/em28xx/em28xx-core.c
@@ -1171,8 +1171,9 @@  int em28xx_resume_extension(struct em28xx *dev)
 	dev_info(&dev->intf->dev, "Resuming extensions\n");
 	mutex_lock(&em28xx_devlist_mutex);
 	list_for_each_entry(ops, &em28xx_extension_devlist, next) {
-		if (ops->resume)
-			ops->resume(dev);
+		if (!ops->resume)
+			continue;
+		ops->resume(dev);
 		if (dev->dev_next)
 			ops->resume(dev->dev_next);
 	}