RE: [robertosassu:ima-snapshots-v1-devel-v1 1/1] security/integrity/ima/ima_fs.c:321 ima_measurements_snap_write() warn: maybe return -EFAULT instead of the bytes remaining?

[Roberto Sassu <roberto.sassu@huawei.com>]

> From: Dan Carpenter <dan.carpenter@linaro.org>
> Sent: Wednesday, November 19, 2025 12:47 PM 
> tree:   https://github.com/robertosassu/linux ima-snapshots-v1-devel-v1
> head:   b0bd002b6caa9d5d4f4d0db2a041b1fd91f33f8a
> commit: b0bd002b6caa9d5d4f4d0db2a041b1fd91f33f8a [1/1] ima: Add
> support for measurement list snapshots
> config: i386-randconfig-141-20251116 (https://download.01.org/0day-
> ci/archive/20251117/202511170428.8scOuqUb-lkp@intel.com/config)
> compiler: gcc-13 (Debian 13.3.0-16) 13.3.0
> 
> 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 <dan.carpenter@linaro.org>
> | Closes: https://lore.kernel.org/r/202511170428.8scOuqUb-lkp@intel.com/
> 
> smatch warnings:
> security/integrity/ima/ima_fs.c:321 ima_measurements_snap_write() warn:
> maybe return -EFAULT instead of the bytes remaining?
> 
> vim +321 security/integrity/ima/ima_fs.c
> 
> b0bd002b6caa9d Roberto Sassu 2025-11-13  309  static ssize_t
> ima_measurements_snap_write(struct file *file,
> b0bd002b6caa9d Roberto Sassu 2025-11-13  310
> 		   const char __user *buf,
> b0bd002b6caa9d Roberto Sassu 2025-11-13  311
> 		   size_t datalen, loff_t *ppos)
> b0bd002b6caa9d Roberto Sassu 2025-11-13  312  {
> b0bd002b6caa9d Roberto Sassu 2025-11-13  313  	unsigned char
> req[SNAPSHOT_REQ_LENGTH];
> b0bd002b6caa9d Roberto Sassu 2025-11-13  314  	int ret;
> b0bd002b6caa9d Roberto Sassu 2025-11-13  315
> b0bd002b6caa9d Roberto Sassu 2025-11-13  316  	if (*ppos > 0 ||
> datalen != SNAPSHOT_REQ_LENGTH)
> b0bd002b6caa9d Roberto Sassu 2025-11-13  317  		return -
> EINVAL;
> b0bd002b6caa9d Roberto Sassu 2025-11-13  318
> b0bd002b6caa9d Roberto Sassu 2025-11-13  319  	ret =
> copy_from_user(req, buf, datalen);
> b0bd002b6caa9d Roberto Sassu 2025-11-13  320  	if (ret < 0)
> b0bd002b6caa9d Roberto Sassu 2025-11-13 @321  		return ret;
> 
> Yep.  This should be:
> 
> 	if (copy_from_user(req, buf, datalen))
> 		return -EFAULT;

Ok, thanks!

Roberto

> b0bd002b6caa9d Roberto Sassu 2025-11-13  322
> b0bd002b6caa9d Roberto Sassu 2025-11-13  323  	if (req[1] != '\n')
> b0bd002b6caa9d Roberto Sassu 2025-11-13  324  		return -
> EINVAL;
> b0bd002b6caa9d Roberto Sassu 2025-11-13  325
> b0bd002b6caa9d Roberto Sassu 2025-11-13  326  	switch (req[0]) {
> b0bd002b6caa9d Roberto Sassu 2025-11-13  327  	case
> SNAPSHOT_REQ_MAKE:
> b0bd002b6caa9d Roberto Sassu 2025-11-13  328  		ret =
> ima_queue_make_snapshot();
> b0bd002b6caa9d Roberto Sassu 2025-11-13  329  		break;
> b0bd002b6caa9d Roberto Sassu 2025-11-13  330  	case
> SNAPSHOT_REQ_DEL:
> b0bd002b6caa9d Roberto Sassu 2025-11-13  331  		ret =
> ima_queue_delete_snapshot();
> b0bd002b6caa9d Roberto Sassu 2025-11-13  332  		break;
> b0bd002b6caa9d Roberto Sassu 2025-11-13  333  	default:
> b0bd002b6caa9d Roberto Sassu 2025-11-13  334  		ret = -EINVAL;
> b0bd002b6caa9d Roberto Sassu 2025-11-13  335  		break;
> b0bd002b6caa9d Roberto Sassu 2025-11-13  336  	}
> b0bd002b6caa9d Roberto Sassu 2025-11-13  337
> b0bd002b6caa9d Roberto Sassu 2025-11-13  338  	if (ret < 0)
> b0bd002b6caa9d Roberto Sassu 2025-11-13  339  		return ret;
> b0bd002b6caa9d Roberto Sassu 2025-11-13  340
> b0bd002b6caa9d Roberto Sassu 2025-11-13  341  	return datalen;
> b0bd002b6caa9d Roberto Sassu 2025-11-13  342  }
> 
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki