[PATCH AUTOSEL 4.9 10/43] media: tw686x: Fix oops on buffer alloc failure

From: Sasha Levin
Date: Thu Sep 06 2018 - 20:49:37 EST


From: Krzysztof Ha?asa <khalasa@xxxxxxx>

[ Upstream commit 5a1a2f63d840dc2631505b607e11ff65ac1b7d3c ]

The error path currently calls tw686x_video_free() which requires
vc->dev to be initialized, causing a NULL dereference on uninitizalized
channels.

Fix this by setting the vc->dev fields for all the channels first.

Fixes: f8afaa8dbc0d ("[media] tw686x: Introduce an interface to support multiple DMA modes")

Signed-off-by: Krzysztof Ha?asa <khalasa@xxxxxxx>
Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
drivers/media/pci/tw686x/tw686x-video.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/media/pci/tw686x/tw686x-video.c b/drivers/media/pci/tw686x/tw686x-video.c
index 0ea8dd44026c..3a06c000f97b 100644
--- a/drivers/media/pci/tw686x/tw686x-video.c
+++ b/drivers/media/pci/tw686x/tw686x-video.c
@@ -1190,6 +1190,14 @@ int tw686x_video_init(struct tw686x_dev *dev)
return err;
}

+ /* Initialize vc->dev and vc->ch for the error path */
+ for (ch = 0; ch < max_channels(dev); ch++) {
+ struct tw686x_video_channel *vc = &dev->video_channels[ch];
+
+ vc->dev = dev;
+ vc->ch = ch;
+ }
+
for (ch = 0; ch < max_channels(dev); ch++) {
struct tw686x_video_channel *vc = &dev->video_channels[ch];
struct video_device *vdev;
@@ -1198,9 +1206,6 @@ int tw686x_video_init(struct tw686x_dev *dev)
spin_lock_init(&vc->qlock);
INIT_LIST_HEAD(&vc->vidq_queued);

- vc->dev = dev;
- vc->ch = ch;
-
/* default settings */
err = tw686x_set_standard(vc, V4L2_STD_NTSC);
if (err)
--
2.17.1