diff options
| author | Mike Isely <isely@pobox.com> | 2019-11-06 12:11:14 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-04 13:39:49 +0100 |
| commit | 61d8117f13976bcb4e70c4c52509238b5efc8354 (patch) | |
| tree | e07411ee691d72988c79217f0a65b73861f4868a /drivers/media/usb | |
| parent | 807185ff15b4562ba8b006fb59ced23f0376b946 (diff) | |
media: pvrusb2: Fix oops on tear-down when radio support is not present
[ Upstream commit 7f404ae9cf2a285f73b3c18ab9303d54b7a3d8e1 ]
In some device configurations there's no radio or radio support in the
driver. That's OK, as the driver sets itself up accordingly. However
on tear-down in these caes it's still trying to tear down radio
related context when there isn't anything there, leading to
dereferences through a null pointer and chaos follows.
How this bug survived unfixed for 11 years in the pvrusb2 driver is a
mystery to me.
[hverkuil: fix two checkpatch warnings]
Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/media/usb')
| -rw-r--r-- | drivers/media/usb/pvrusb2/pvrusb2-v4l2.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/media/usb/pvrusb2/pvrusb2-v4l2.c b/drivers/media/usb/pvrusb2/pvrusb2-v4l2.c index 2cc4d2b6f810..d18ced28797d 100644 --- a/drivers/media/usb/pvrusb2/pvrusb2-v4l2.c +++ b/drivers/media/usb/pvrusb2/pvrusb2-v4l2.c @@ -919,8 +919,12 @@ static void pvr2_v4l2_internal_check(struct pvr2_channel *chp) pvr2_v4l2_dev_disassociate_parent(vp->dev_video); pvr2_v4l2_dev_disassociate_parent(vp->dev_radio); if (!list_empty(&vp->dev_video->devbase.fh_list) || - !list_empty(&vp->dev_radio->devbase.fh_list)) + (vp->dev_radio && + !list_empty(&vp->dev_radio->devbase.fh_list))) { + pvr2_trace(PVR2_TRACE_STRUCT, + "pvr2_v4l2 internal_check exit-empty id=%p", vp); return; + } pvr2_v4l2_destroy_no_lock(vp); } @@ -994,7 +998,8 @@ static int pvr2_v4l2_release(struct file *file) kfree(fhp); if (vp->channel.mc_head->disconnect_flag && list_empty(&vp->dev_video->devbase.fh_list) && - list_empty(&vp->dev_radio->devbase.fh_list)) { + (!vp->dev_radio || + list_empty(&vp->dev_radio->devbase.fh_list))) { pvr2_v4l2_destroy_no_lock(vp); } return 0; |