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author | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-11-16 16:13:02 +0100 |
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committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-11-16 16:16:22 +0100 |
commit | 62de7d99dcfe5ceff0c40d27a819a2256c8dfc73 (patch) | |
tree | 84e6fe6f778dacaf4cc870d3b5cbddea82aec827 /drivers/media/usb/usbtv | |
parent | [media] usbtv: add video controls (diff) | |
download | linux-62de7d99dcfe5ceff0c40d27a819a2256c8dfc73.tar.xz linux-62de7d99dcfe5ceff0c40d27a819a2256c8dfc73.zip |
[media] usbtv: don't do DMA on stack
As reported by smatch:
drivers/media/usb/usbtv/usbtv-video.c:716 usbtv_s_ctrl() error: doing dma on the stack (data)
drivers/media/usb/usbtv/usbtv-video.c:758 usbtv_s_ctrl() error: doing dma on the stack (data)
We should not do it, as it won't work on Kernels 4.9 and upper.
So, alloc a buffer for it.
Fixes: c53a846c48f2 ("[media] usbtv: add video controls")
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'drivers/media/usb/usbtv')
-rw-r--r-- | drivers/media/usb/usbtv/usbtv-video.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/drivers/media/usb/usbtv/usbtv-video.c b/drivers/media/usb/usbtv/usbtv-video.c index 86ffbf8780f2..d3b6d3dfaa09 100644 --- a/drivers/media/usb/usbtv/usbtv-video.c +++ b/drivers/media/usb/usbtv/usbtv-video.c @@ -704,10 +704,14 @@ static int usbtv_s_ctrl(struct v4l2_ctrl *ctrl) { struct usbtv *usbtv = container_of(ctrl->handler, struct usbtv, ctrl); - u8 data[3]; + u8 *data; u16 index, size; int ret; + data = kmalloc(3, GFP_KERNEL); + if (!data) + return -ENOMEM; + /* * Read in the current brightness/contrast registers. We need them * both, because the values are for some reason interleaved. @@ -717,6 +721,8 @@ static int usbtv_s_ctrl(struct v4l2_ctrl *ctrl) usb_sndctrlpipe(usbtv->udev, 0), USBTV_CONTROL_REG, USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE, 0, USBTV_BASE + 0x0244, (void *)data, 3, 0); + if (ret < 0) + goto error; } switch (ctrl->id) { @@ -752,6 +758,7 @@ static int usbtv_s_ctrl(struct v4l2_ctrl *ctrl) } break; default: + kfree(data); return -EINVAL; } @@ -759,12 +766,13 @@ static int usbtv_s_ctrl(struct v4l2_ctrl *ctrl) USBTV_CONTROL_REG, USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE, 0, index, (void *)data, size, 0); - if (ret < 0) { + +error: + if (ret < 0) dev_warn(usbtv->dev, "Failed to submit a control request.\n"); - return ret; - } - return 0; + kfree(data); + return ret; } static const struct v4l2_ctrl_ops usbtv_ctrl_ops = { |