Hi Daniel, Thank you for the patch. On Fri, Aug 07, 2020 at 05:35:30AM -0300, Daniel W. S. Almeida wrote: > From: "Daniel W. S. Almeida" <dwlsalmeida@xxxxxxxxx> > > Fixes the following coccinelle report: > > drivers/media/usb/uvc/uvc_ctrl.c:1860:5-11: > ERROR: invalid reference to the index variable of the iterator on line 1854 > > By introducing a temporary variable to iterate the list. > > Do not dereference the 'entity' pointer if it is not found in the list. > > Found using - Coccinelle (http://coccinelle.lip6.fr) > > Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@xxxxxxxxx> > --- > drivers/media/usb/uvc/uvc_ctrl.c | 13 ++++++++----- > 1 file changed, 8 insertions(+), 5 deletions(-) > > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c > index e399b9fad757..567bdedc2ff2 100644 > --- a/drivers/media/usb/uvc/uvc_ctrl.c > +++ b/drivers/media/usb/uvc/uvc_ctrl.c > @@ -1842,7 +1842,8 @@ static int uvc_ctrl_init_xu_ctrl(struct uvc_device *dev, > int uvc_xu_ctrl_query(struct uvc_video_chain *chain, > struct uvc_xu_control_query *xqry) > { > - struct uvc_entity *entity; > + struct uvc_entity *entity = NULL; > + struct uvc_entity *cursor = NULL; cursor doesn't have to be initialized to NULL. It may be a style preference, but instead of a cursor variable that doesn't tell in its name what it refers to, I'd prefer a bool found = false; > struct uvc_control *ctrl; > unsigned int i, found = 0; > u32 reqflags; > @@ -1851,13 +1852,15 @@ int uvc_xu_ctrl_query(struct uvc_video_chain *chain, > int ret; > > /* Find the extension unit. */ > - list_for_each_entry(entity, &chain->entities, chain) { > - if (UVC_ENTITY_TYPE(entity) == UVC_VC_EXTENSION_UNIT && > - entity->id == xqry->unit) > + list_for_each_entry(cursor, &chain->entities, chain) { > + if (UVC_ENTITY_TYPE(cursor) == UVC_VC_EXTENSION_UNIT && > + cursor->id == xqry->unit) { All this would keep using entity. > + entity = cursor; And this would be replaced with found = true; > break; > + } > } > > - if (entity->id != xqry->unit) { > + if (!entity || entity->id != xqry->unit) { The second part of the check isn't needed, it was only meant to check if the entity has been found. Here, we'd have if (!found) { I'f you're OK with these changes there's no need to resubmit, I can update when applying. Please let me know how you'd like to proceed. > uvc_trace(UVC_TRACE_CONTROL, "Extension unit %u not found.\n", > xqry->unit); > return -ENOENT; -- Regards, Laurent Pinchart
