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authorSage Weil <sage@inktank.com>2012-08-21 12:11:51 -0700
committerSage Weil <sage@inktank.com>2012-08-21 15:55:28 -0700
commit45f2e081f573526977abfa781a12728f83e9641f (patch)
tree0335f7ad27ed8506504201a5e558126b2ede058f /fs/ceph
parent6d4221b53707486dfad3f5bfe568d2ce7f4c9863 (diff)
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>
Diffstat (limited to 'fs/ceph')
-rw-r--r--fs/ceph/ioctl.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/ceph/ioctl.c b/fs/ceph/ioctl.c
index 8e3fb69fbe6..1396ceb4679 100644
--- a/fs/ceph/ioctl.c
+++ b/fs/ceph/ioctl.c
@@ -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 */