From: Jia-Ju Bai Date: Mon, 29 Jul 2019 10:14:44 +0000 (+0200) Subject: media: usb: msi2500: Fix a possible null-pointer dereference in msi2500_stop_streaming() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=3ec7fdc58363bb204c75d6158e3560fd7cabbf5c;p=linux.git media: usb: msi2500: Fix a possible null-pointer dereference in msi2500_stop_streaming() In msi2500_stop_streaming(), there is an if statement on line 870 to check whether dev->udev is NULL: if (dev->udev) When dev->udev is NULL, it is used on line 877: msi2500_ctrl_msg(dev, CMD_STOP_STREAMING, 0) usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0), ...) Thus, a possible null-pointer dereference may occur. To fix this bug, dev->udev is checked before calling msi2500_ctrl_msg(). This bug is found by a static analysis tool STCheck written by us. Signed-off-by: Jia-Ju Bai Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/usb/msi2500/msi2500.c b/drivers/media/usb/msi2500/msi2500.c index 65be6f140fe83..269f3ef34bc90 100644 --- a/drivers/media/usb/msi2500/msi2500.c +++ b/drivers/media/usb/msi2500/msi2500.c @@ -867,7 +867,7 @@ static void msi2500_stop_streaming(struct vb2_queue *vq) /* according to tests, at least 700us delay is required */ msleep(20); - if (!msi2500_ctrl_msg(dev, CMD_STOP_STREAMING, 0)) { + if (dev->udev && !msi2500_ctrl_msg(dev, CMD_STOP_STREAMING, 0)) { /* sleep USB IF / ADC */ msi2500_ctrl_msg(dev, CMD_WREG, 0x01000003); }