Hi Mauro,
Thank you for the patch.
On Mon, Jun 21, 2021 at 03:23:35PM +0200, Mauro Carvalho Chehab wrote:
As warned by smatch: drivers/media/usb/uvc/uvc_v4l2.c:911 uvc_ioctl_g_input() error: doing dma on the stack (&i) drivers/media/usb/uvc/uvc_v4l2.c:943 uvc_ioctl_s_input() error: doing dma on the stack (&i)
those two functions call uvc_query_ctrl passing a pointer to a data at the DMA stack. those are used to send URBs via usb_control_msg(). Using DMA stack is not supported and should not work anymore on modern Linux versions.
So, use a temporary buffer, allocated together with struct uvc_video_chain.
The second part of the sentence isn't correct anymore.
Cc: stable@vger.kernel.org # Kernel 4.9 and upper Signed-off-by: Mauro Carvalho Chehab mchehab+huawei@kernel.org
drivers/media/usb/uvc/uvc_v4l2.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-)
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c index 252136cc885c..d680ae8a5f87 100644 --- a/drivers/media/usb/uvc/uvc_v4l2.c +++ b/drivers/media/usb/uvc/uvc_v4l2.c @@ -899,8 +899,8 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input) { struct uvc_fh *handle = fh; struct uvc_video_chain *chain = handle->chain;
- char *buf;
I'd make this
u8 *buf;
as the selector value is unsigned.
int ret;
- u8 i;
if (chain->selector == NULL || (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) { @@ -908,13 +908,18 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input) return 0; }
- buf = kmalloc(1, GFP_KERNEL);
MIssing error check.
- ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR, chain->selector->id, chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL,
&i, 1);
buf, 1);
- *input = i - 1;
- *input = *buf;
- kfree(buf);
- return 0;
} @@ -922,8 +927,8 @@ static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input) { struct uvc_fh *handle = fh; struct uvc_video_chain *chain = handle->chain;
- char *buf;
u8 * here too.
int ret;
- u32 i;
ret = uvc_acquire_privileges(handle); if (ret < 0) @@ -939,10 +944,15 @@ static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input) if (input >= chain->selector->bNrInPins) return -EINVAL;
- i = input + 1;
- return uvc_query_ctrl(chain->dev, UVC_SET_CUR, chain->selector->id,
chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL,&i, 1);
- buf = kmalloc(1, GFP_KERNEL);
And missing error check.
- *buf = input + 1;
- ret = uvc_query_ctrl(chain->dev, UVC_SET_CUR, chain->selector->id,
chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL,buf, 1);- kfree(buf);
- return ret;
} static int uvc_ioctl_queryctrl(struct file *file, void *fh,