If userspace calls this ioctl with fsu_length (the length of the
fsuuid.fsu_uuid array) set to zero, ext4 copies the desired uuid length
out to userspace. The kernel call returned a result from a valid input,
so the return value here should be zero, not EINVAL.
While we're at it, fix the copy_to_user call to make it clear that we're
only copying out fsu_len.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Catherine Hoang <catherine.hoang@oracle.com>
Link: https://lore.kernel.org/r/166811138914.327006.9241306894437166566.stgit@magnolia
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
if (fsuuid.fsu_len == 0) {
fsuuid.fsu_len = UUID_SIZE;
- if (copy_to_user(ufsuuid, &fsuuid, sizeof(fsuuid.fsu_len)))
+ if (copy_to_user(&ufsuuid->fsu_len, &fsuuid.fsu_len,
+ sizeof(fsuuid.fsu_len)))
return -EFAULT;
- return -EINVAL;
+ return 0;
}
if (fsuuid.fsu_len != UUID_SIZE || fsuuid.fsu_flags != 0)