From: Darrick J. Wong <djwong@xxxxxxxxxx>
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@xxxxxxxxxx>
---
fs/ext4/ioctl.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 95dfea28bf4e..5f91f3ad3e50 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -1153,9 +1153,10 @@ static int ext4_ioctl_getuuid(struct ext4_sb_info *sbi,
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)
