[PATCH AUTOSEL 5.8 057/132] media: uvcvideo: Fix dereference of out-of-bound list iterator

Sasha Levin
2020-10-26T23:53:48Z

From: "Daniel W. S. Almeida" <dwlsalmeida@gmail.com>

[ Upstream commit f875bcc375c738bf2f599ff2e1c5b918dbd07c45 ]

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 adding a boolean variable to check if the loop has found the

Found using - Coccinelle (http://coccinelle.lip6.fr)

[Replace cursor variable with bool found]

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/media/usb/uvc/uvc_ctrl.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index e399b9fad7574..aed84528758f6 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1844,30 +1844,35 @@ int uvc_xu_ctrl_query(struct uvc_video_chain *chain,
{
struct uvc_entity *entity;
struct uvc_control *ctrl;
- unsigned int i, found = 0;
+ unsigned int i;
+ bool found;
u32 reqflags;
u16 size;
u8 *data = NULL;
int ret;

/* Find the extension unit. */
+ found = false;
list_for_each_entry(entity, &chain->entities, chain) {
if (UVC_ENTITY_TYPE(entity) == UVC_VC_EXTENSION_UNIT &&
- entity->id == xqry->unit)
+ entity->id == xqry->unit) {
+ found = true;
break;
+ }
}

- if (entity->id != xqry->unit) {
+ if (!found) {
uvc_trace(UVC_TRACE_CONTROL, "Extension unit %u not found.\n",
xqry->unit);
return -ENOENT;
}

/* Find the control and perform delayed initialization if needed. */
+ found = false;
for (i = 0; i < entity->ncontrols; ++i) {
ctrl = &entity->controls[i];
if (ctrl->index == xqry->selector - 1) {
- found = 1;
+ found = true;
break;
}
}
--
2.25.1