[91/93] dm stripe: avoid divide by zero with invalid stripe count

[Greg KH]

2.6.32-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Nikanth Karthikesan <knikanth@xxxxxxx>

commit 781248c1b50c776a9ef4be1130f84ced1cba42fe upstream.

If a table containing zero as stripe count is passed into stripe_ctr
the code attempts to divide by zero.

This patch changes DM_TABLE_LOAD to return -EINVAL if the stripe count
is zero.

We now get the following error messages:
  device-mapper: table: 253:0: striped: Invalid stripe count
  device-mapper: ioctl: error adding target to table

Signed-off-by: Nikanth Karthikesan <knikanth@xxxxxxx>
Signed-off-by: Alasdair G Kergon <agk@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 drivers/md/dm-stripe.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -110,7 +110,7 @@ static int stripe_ctr(struct dm_target *
 	}
 
 	stripes = simple_strtoul(argv[0], &end, 10);
-	if (*end) {
+	if (!stripes || *end) {
 		ti->error = "Invalid stripe count";
 		return -EINVAL;
 	}


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