From: Andre Noll <maan@systemlinux.org>
Date: Mon, 21 Jul 2008 04:42:07 +0000 (+1000)
Subject: md: Fix check for overlapping devices.
X-Git-Tag: v2.6.27-rc1~957^2~5
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d07bd3bcc456228b56a790897162a634691fed9b;p=linux-2.6

md: Fix check for overlapping devices.

The checks in overlaps() expect all parameters either in block-based
or sector-based quantities. However, its single caller passes two
rdev->data_offset arguments as well as two rdev->size arguments, the
former being sector counts while the latter are measured in 1K blocks.

This could cause rdev_size_store() to accept an invalid size from user
space. Fix it by passing only sector-based quantities to overlaps().

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
---

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 95466bb089..a2813fa06b 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2143,8 +2143,9 @@ rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
 				if (test_bit(AllReserved, &rdev2->flags) ||
 				    (rdev->bdev == rdev2->bdev &&
 				     rdev != rdev2 &&
-				     overlaps(rdev->data_offset, rdev->size,
-					    rdev2->data_offset, rdev2->size))) {
+				     overlaps(rdev->data_offset, rdev->size * 2,
+					      rdev2->data_offset,
+					      rdev2->size * 2))) {
 					overlap = 1;
 					break;
 				}