ceph: avoid divide by zero in __validate_layout()

If "l->stripe_unit" is zero the the mod on the next line will cause a
divide by zero bug.  This comes from the copy_from_user() in
ceph_ioctl_set_layout_policy().  Passing 0 is valid, though (it means
"do not change") so avoid the % check in that case.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
This commit is contained in:
Sage Weil 2012-08-21 12:11:51 -07:00
parent 6d4221b537
commit 45f2e081f5
1 changed files with 2 additions and 1 deletions

View File

@ -42,7 +42,8 @@ static long __validate_layout(struct ceph_mds_client *mdsc,
/* validate striping parameters */
if ((l->object_size & ~PAGE_MASK) ||
(l->stripe_unit & ~PAGE_MASK) ||
((unsigned)l->object_size % (unsigned)l->stripe_unit))
(l->stripe_unit != 0 &&
((unsigned)l->object_size % (unsigned)l->stripe_unit)))
return -EINVAL;
/* make sure it's a valid data pool */