2016-03-04 02:25:06

by Shuah Khan

Subject: [PATCH] media: fix null pointer dereference in v4l_vb2q_enable_media_source()

Fix the null pointer dereference in v4l_vb2q_enable_media_source().
DVB only drivers don't have valid struct v4l2_fh pointer.

[ 548.443272] BUG: unable to handle kernel NULL pointer dereference
at 0000000000000010
[ 548.452036] IP: [<ffffffffc020ffc9>]
v4l_vb2q_enable_media_source+0x9/0x50 [videodev]
[ 548.460792] PGD b820e067 PUD bb3df067 PMD 0
[ 548.465582] Oops: 0000 [#1] SMP

Signed-off-by: Shuah Khan <[email protected]>
Reported-by: Olli Salonen <[email protected]>
---
drivers/media/v4l2-core/v4l2-mc.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/media/v4l2-core/v4l2-mc.c b/drivers/media/v4l2-core/v4l2-mc.c
index 643686d..a39a3cd 100644
--- a/drivers/media/v4l2-core/v4l2-mc.c
+++ b/drivers/media/v4l2-core/v4l2-mc.c
@@ -214,6 +214,8 @@ int v4l_vb2q_enable_media_source(struct vb2_queue *q)
{
struct v4l2_fh *fh = q->owner;

- return v4l_enable_media_source(fh->vdev);
+ if (fh && fh->vdev)
+ return v4l_enable_media_source(fh->vdev);
+ return 0;
}
EXPORT_SYMBOL_GPL(v4l_vb2q_enable_media_source);
--
2.5.0

2016-03-04 04:34:11

by Olli Salonen

Subject: Re: [PATCH] media: fix null pointer dereference in v4l_vb2q_enable_media_source()

Hi Shuah,

Thanks for your quick reaction. This patch seems to fix the oops I got earlier.

Tested-by: Olli Salonen <[email protected]>

Cheers,
-olli

On 4 March 2016 at 04:24, Shuah Khan <[email protected]> wrote:
> Fix the null pointer dereference in v4l_vb2q_enable_media_source().
> DVB only drivers don't have valid struct v4l2_fh pointer.
>
> [ 548.443272] BUG: unable to handle kernel NULL pointer dereference
> at 0000000000000010
> [ 548.452036] IP: [<ffffffffc020ffc9>]
> v4l_vb2q_enable_media_source+0x9/0x50 [videodev]
> [ 548.460792] PGD b820e067 PUD bb3df067 PMD 0
> [ 548.465582] Oops: 0000 [#1] SMP
>
> Signed-off-by: Shuah Khan <[email protected]>
> Reported-by: Olli Salonen <[email protected]>
> ---
> drivers/media/v4l2-core/v4l2-mc.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-mc.c b/drivers/media/v4l2-core/v4l2-mc.c
> index 643686d..a39a3cd 100644
> --- a/drivers/media/v4l2-core/v4l2-mc.c
> +++ b/drivers/media/v4l2-core/v4l2-mc.c
> @@ -214,6 +214,8 @@ int v4l_vb2q_enable_media_source(struct vb2_queue *q)
> {
> struct v4l2_fh *fh = q->owner;
>
> - return v4l_enable_media_source(fh->vdev);
> + if (fh && fh->vdev)
> + return v4l_enable_media_source(fh->vdev);
> + return 0;
> }
> EXPORT_SYMBOL_GPL(v4l_vb2q_enable_media_source);
> --
> 2.5.0
>