diff options
| author | Mauro Carvalho Chehab <mchehab+huawei@kernel.org> | 2021-06-17 14:33:29 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-22 11:41:23 +0200 |
| commit | 2bed3f25a19f2c3ef204e1aafe75a66fe2474d21 (patch) | |
| tree | 54dbfe08fea532ba40453e745a0e08707d652982 /drivers/media | |
| parent | 4619198c2854d3601c01a0e8658c5b9864cc5a4e (diff) | |
media: uvc: don't do DMA on stack
commit 1a10d7fdb6d0e235e9d230916244cc2769d3f170 upstream.
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 kmalloc'ed buffer.
Cc: stable@vger.kernel.org # Kernel 4.9 and upper
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/media')
| -rw-r--r-- | drivers/media/usb/uvc/uvc_v4l2.c | 34 |
1 files changed, 23 insertions, 11 deletions
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c index 154f5bd45940..049d664e94f0 100644 --- a/drivers/media/usb/uvc/uvc_v4l2.c +++ b/drivers/media/usb/uvc/uvc_v4l2.c @@ -866,8 +866,8 @@ 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; + u8 *buf; int ret; - u8 i; if (chain->selector == NULL || (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) { @@ -875,22 +875,27 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input) return 0; } + buf = kmalloc(1, GFP_KERNEL); + if (!buf) + return -ENOMEM; + ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR, chain->selector->id, chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL, - &i, 1); - if (ret < 0) - return ret; + buf, 1); + if (!ret) + *input = *buf - 1; - *input = i - 1; - return 0; + kfree(buf); + + return ret; } 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; + u8 *buf; int ret; - u32 i; ret = uvc_acquire_privileges(handle); if (ret < 0) @@ -906,10 +911,17 @@ 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); + if (!buf) + return -ENOMEM; + + *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, |