[android-common:android14-kiwi-6.1 290/290] drivers/gpu/drm/drm_displayid.c:31 validate_displayid() warn: passing positive error code '(-22)' to 'PTR_ERR'

[kernel test robot <lkp@intel.com>]

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
TO: cros-kernel-buildreports@googlegroups.com

tree:   https://android.googlesource.com/kernel/common android14-kiwi-6.1
head:   d71786d14d19c4686859f15454883795f59bef15
commit: 4b17053ba268bf952c19ecb58d66d5d72e782d13 [290/290] drm/displayid: add displayid_get_header() and check bounds better
:::::: branch date: 28 hours ago
:::::: commit date: 1 year, 10 months ago
config: i386-randconfig-141-20250316 (https://download.01.org/0day-ci/archive/20250316/202503161817.AZJv9oo9-lkp@intel.com/config)
compiler: clang version 19.1.7 (https://github.com/llvm/llvm-project cd708029e0b2869e80abe31ddb175f7c35361f90)

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@intel.com>
| Reported-by: Dan Carpenter <error27@gmail.com>
| Closes: https://lore.kernel.org/r/202503161817.AZJv9oo9-lkp@intel.com/

smatch warnings:
drivers/gpu/drm/drm_displayid.c:31 validate_displayid() warn: passing positive error code '(-22)' to 'PTR_ERR'

vim +31 drivers/gpu/drm/drm_displayid.c

4b17053ba268bf9 Jani Nikula 2023-02-16  22  
4cc4f09eaa06178 Jani Nikula 2021-03-29  23  static int validate_displayid(const u8 *displayid, int length, int idx)
4cc4f09eaa06178 Jani Nikula 2021-03-29  24  {
4cc4f09eaa06178 Jani Nikula 2021-03-29  25  	int i, dispid_length;
4cc4f09eaa06178 Jani Nikula 2021-03-29  26  	u8 csum = 0;
339be1a8e9af736 Jani Nikula 2021-03-29  27  	const struct displayid_header *base;
4cc4f09eaa06178 Jani Nikula 2021-03-29  28  
4b17053ba268bf9 Jani Nikula 2023-02-16  29  	base = displayid_get_header(displayid, length, idx);
4b17053ba268bf9 Jani Nikula 2023-02-16  30  	if (IS_ERR(base))
4b17053ba268bf9 Jani Nikula 2023-02-16 @31  		return PTR_ERR(base);
4cc4f09eaa06178 Jani Nikula 2021-03-29  32  
4cc4f09eaa06178 Jani Nikula 2021-03-29  33  	DRM_DEBUG_KMS("base revision 0x%x, length %d, %d %d\n",
4cc4f09eaa06178 Jani Nikula 2021-03-29  34  		      base->rev, base->bytes, base->prod_id, base->ext_count);
4cc4f09eaa06178 Jani Nikula 2021-03-29  35  
4cc4f09eaa06178 Jani Nikula 2021-03-29  36  	/* +1 for DispID checksum */
4cc4f09eaa06178 Jani Nikula 2021-03-29  37  	dispid_length = sizeof(*base) + base->bytes + 1;
4cc4f09eaa06178 Jani Nikula 2021-03-29  38  	if (dispid_length > length - idx)
4cc4f09eaa06178 Jani Nikula 2021-03-29  39  		return -EINVAL;
4cc4f09eaa06178 Jani Nikula 2021-03-29  40  
4cc4f09eaa06178 Jani Nikula 2021-03-29  41  	for (i = 0; i < dispid_length; i++)
4cc4f09eaa06178 Jani Nikula 2021-03-29  42  		csum += displayid[idx + i];
4cc4f09eaa06178 Jani Nikula 2021-03-29  43  	if (csum) {
4cc4f09eaa06178 Jani Nikula 2021-03-29  44  		DRM_NOTE("DisplayID checksum invalid, remainder is %d\n", csum);
4cc4f09eaa06178 Jani Nikula 2021-03-29  45  		return -EINVAL;
4cc4f09eaa06178 Jani Nikula 2021-03-29  46  	}
4cc4f09eaa06178 Jani Nikula 2021-03-29  47  
4cc4f09eaa06178 Jani Nikula 2021-03-29  48  	return 0;
4cc4f09eaa06178 Jani Nikula 2021-03-29  49  }
4cc4f09eaa06178 Jani Nikula 2021-03-29  50  

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