From 62de7d99dcfe5ceff0c40d27a819a2256c8dfc73 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Wed, 16 Nov 2016 13:13:02 -0200 Subject: [PATCH] [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 --- drivers/media/usb/usbtv/usbtv-video.c | 18 +++++++++++++----- 1 file 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 = { -- 2.39.2