| Message ID | 1463055292-25053-2-git-send-email-sakari.ailus@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 05/12/2016 02:14 PM, Sakari Ailus wrote: > An earlier patch fixing an input validation issue introduced another > issue: vb2_core_dqbuf() is called with pb argument value NULL in some > cases, causing a NULL pointer dereference. Fix this by skipping the > verification as there's nothing to verify. > > Signed-off-by: David R <david@unsolicited.net> > > Use if () instead of ? :; it's nicer that way. Improve the comment in the > code as well. This comment doesn't seem applicable to this patch. Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com> Hans > > Fixes: e7e0c3e26587 ("[media] videobuf2-core: Check user space planes array in dqbuf") > > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> > Cc: stable@vger.kernel.org # for v4.4 and later > --- > drivers/media/v4l2-core/videobuf2-core.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c > index 9fbcb67..633fc1a 100644 > --- a/drivers/media/v4l2-core/videobuf2-core.c > +++ b/drivers/media/v4l2-core/videobuf2-core.c > @@ -1648,7 +1648,7 @@ static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb, > void *pb, int nonblocking) > { > unsigned long flags; > - int ret; > + int ret = 0; > > /* > * Wait for at least one buffer to become available on the done_list. > @@ -1664,10 +1664,12 @@ static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb, > spin_lock_irqsave(&q->done_lock, flags); > *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry); > /* > - * Only remove the buffer from done_list if v4l2_buffer can handle all > - * the planes. > + * Only remove the buffer from done_list if all planes can be > + * handled. Some cases such as V4L2 file I/O and DVB have pb > + * == NULL; skip the check then as there's nothing to verify. > */ > - ret = call_bufop(q, verify_planes_array, *vb, pb); > + if (pb) > + ret = call_bufop(q, verify_planes_array, *vb, pb); > if (!ret) > list_del(&(*vb)->done_entry); > spin_unlock_irqrestore(&q->done_lock, flags); > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Hans, Hans Verkuil wrote: > On 05/12/2016 02:14 PM, Sakari Ailus wrote: >> An earlier patch fixing an input validation issue introduced another >> issue: vb2_core_dqbuf() is called with pb argument value NULL in some >> cases, causing a NULL pointer dereference. Fix this by skipping the >> verification as there's nothing to verify. >> >> Signed-off-by: David R <david@unsolicited.net> >> >> Use if () instead of ? :; it's nicer that way. Improve the comment in the >> code as well. > > This comment doesn't seem applicable to this patch. Compared to the original patch. I can sure drop the comment as well, it's not that important. > > Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com> Thanks!
diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index 9fbcb67..633fc1a 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -1648,7 +1648,7 @@ static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb, void *pb, int nonblocking) { unsigned long flags; - int ret; + int ret = 0; /* * Wait for at least one buffer to become available on the done_list. @@ -1664,10 +1664,12 @@ static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb, spin_lock_irqsave(&q->done_lock, flags); *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry); /* - * Only remove the buffer from done_list if v4l2_buffer can handle all - * the planes. + * Only remove the buffer from done_list if all planes can be + * handled. Some cases such as V4L2 file I/O and DVB have pb + * == NULL; skip the check then as there's nothing to verify. */ - ret = call_bufop(q, verify_planes_array, *vb, pb); + if (pb) + ret = call_bufop(q, verify_planes_array, *vb, pb); if (!ret) list_del(&(*vb)->done_entry); spin_unlock_irqrestore(&q->done_lock, flags);