LoadPin: Return EFAULT on copy_from_user() failures

The copy_from_user() function returns the number of bytes remaining to
be copied on a failure. Such failures should return -EFAULT to high
levels.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 3f805f8cc2 ("LoadPin: Enable loading from trusted dm-verity devices")
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: linux-security-module@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
This commit is contained in:
Kees Cook 2022-08-16 12:14:54 -07:00
parent 27603a606f
commit 6a3981af3f

View File

@ -356,13 +356,11 @@ static long dm_verity_ioctl(struct file *filp, unsigned int cmd, unsigned long a
{
void __user *uarg = (void __user *)arg;
unsigned int fd;
int rc;
switch (cmd) {
case LOADPIN_IOC_SET_TRUSTED_VERITY_DIGESTS:
rc = copy_from_user(&fd, uarg, sizeof(fd));
if (rc)
return rc;
if (copy_from_user(&fd, uarg, sizeof(fd)))
return -EFAULT;
return read_trusted_verity_root_digests(fd);