Hi Yunke, kernel test robot noticed the following build warnings: https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Yunke-Cao/media-v4l2_ctrl-Add-V4L2_CTRL_TYPE_RECT/20231201-152501 base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing patch link: https://lore.kernel.org/r/20231201071907.3080126-6-yunkec%40google.com patch subject: [PATCH v14 05/11] media: uvcvideo: Add support for compound controls config: powerpc64-randconfig-r081-20231204 (https://download.01.org/0day-ci/archive/20231206/202312060523.tldbovNM-lkp@xxxxxxxxx/config) compiler: powerpc64-linux-gcc (GCC) 13.2.0 reproduce: (https://download.01.org/0day-ci/archive/20231206/202312060523.tldbovNM-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> | Closes: https://lore.kernel.org/r/202312060523.tldbovNM-lkp@xxxxxxxxx/ smatch warnings: drivers/media/usb/uvc/uvc_ctrl.c:2065 __uvc_ctrl_set_compound() warn: maybe return -EFAULT instead of the bytes remaining? vim +2065 drivers/media/usb/uvc/uvc_ctrl.c 1a1a2af88920e9 Yunke Cao 2023-12-01 2040 static int __uvc_ctrl_set_compound(struct uvc_control_mapping *mapping, 1a1a2af88920e9 Yunke Cao 2023-12-01 2041 struct v4l2_ext_control *xctrl, 1a1a2af88920e9 Yunke Cao 2023-12-01 2042 struct uvc_control *ctrl) 1a1a2af88920e9 Yunke Cao 2023-12-01 2043 { 1a1a2af88920e9 Yunke Cao 2023-12-01 2044 u8 *data; 1a1a2af88920e9 Yunke Cao 2023-12-01 2045 int ret; 1a1a2af88920e9 Yunke Cao 2023-12-01 2046 1a1a2af88920e9 Yunke Cao 2023-12-01 2047 if (xctrl->size != mapping->v4l2_size / 8) 1a1a2af88920e9 Yunke Cao 2023-12-01 2048 return -EINVAL; 1a1a2af88920e9 Yunke Cao 2023-12-01 2049 1a1a2af88920e9 Yunke Cao 2023-12-01 2050 data = kmalloc(xctrl->size, GFP_KERNEL); 1a1a2af88920e9 Yunke Cao 2023-12-01 2051 if (!data) 1a1a2af88920e9 Yunke Cao 2023-12-01 2052 return -ENOMEM; 1a1a2af88920e9 Yunke Cao 2023-12-01 2053 1a1a2af88920e9 Yunke Cao 2023-12-01 2054 ret = copy_from_user(data, xctrl->ptr, xctrl->size); copy_from_user() never returns negatives, it returns the number of bytes remaining to be copied. This should be: if (copy_from_user(data, xctrl->ptr, xctrl->size)) { ret = -EFAULT; goto out; } 1a1a2af88920e9 Yunke Cao 2023-12-01 2055 if (ret < 0) 1a1a2af88920e9 Yunke Cao 2023-12-01 2056 goto out; 1a1a2af88920e9 Yunke Cao 2023-12-01 2057 1a1a2af88920e9 Yunke Cao 2023-12-01 2058 ret = mapping->set_compound(mapping, data, 1a1a2af88920e9 Yunke Cao 2023-12-01 2059 uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT)); 1a1a2af88920e9 Yunke Cao 2023-12-01 2060 1a1a2af88920e9 Yunke Cao 2023-12-01 2061 __uvc_ctrl_get_compound(mapping, ctrl, UVC_CTRL_DATA_CURRENT, xctrl); 1a1a2af88920e9 Yunke Cao 2023-12-01 2062 1a1a2af88920e9 Yunke Cao 2023-12-01 2063 out: 1a1a2af88920e9 Yunke Cao 2023-12-01 2064 kfree(data); 1a1a2af88920e9 Yunke Cao 2023-12-01 @2065 return ret; 1a1a2af88920e9 Yunke Cao 2023-12-01 2066 } -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
