From 45f2e081f573526977abfa781a12728f83e9641f Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Tue, 21 Aug 2012 12:11:51 -0700 Subject: [PATCH] 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 Signed-off-by: Sage Weil Reviewed-by: Alex Elder --- fs/ceph/ioctl.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/ceph/ioctl.c b/fs/ceph/ioctl.c index 8e3fb69fbe62..1396ceb46797 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 */