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authorAndy Isaacson <adi@hexapodia.org>2007-03-16 13:38:04 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-03-16 19:25:03 -0700
commitbed31ed9e1cd71d98ff0bc9212100adee523a10a (patch)
treebbba995c877dfc161d0ad5e789be684084e1dfe0 /drivers/md/linear.c
parent48670a1e018a9c0b83dc78e3b71ffb26391ee4b6 (diff)
[PATCH] fix read past end of array in md/linear.c
When iterating through an array, one must be careful to test one's index variable rather than another similarly-named variable. The loop will read off the end of conf->disks[] in the following (pathological) case: % dd bs=1 seek=840716287 if=/dev/zero of=d1 count=1 % for i in 2 3 4; do dd if=/dev/zero of=d$i bs=1k count=$(($i+150)); done % ./vmlinux ubd0=root ubd1=d1 ubd2=d2 ubd3=d3 ubd4=d4 # mdadm -C /dev/md0 --level=linear --raid-devices=4 /dev/ubd[1234] adding some printks, I saw this: [42949374.960000] hash_spacing = 821120 [42949374.960000] cnt = 4 [42949374.960000] min_spacing = 801 [42949374.960000] j=0 size=820928 sz=820928 [42949374.960000] i=0 sz=820928 hash_spacing=820928 [42949374.960000] j=1 size=64 sz=64 [42949374.960000] j=2 size=64 sz=128 [42949374.960000] j=3 size=64 sz=192 [42949374.960000] j=4 size=1515870810 sz=1515871002 Cc: Gautham R Shenoy <ego@in.ibm.com> Acked-by: Neil Brown <neilb@cse.unsw.edu.au> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/md/linear.c')
-rw-r--r--drivers/md/linear.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index c625ddb8833..d5ecd2d5304 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -188,7 +188,7 @@ static linear_conf_t *linear_conf(mddev_t *mddev, int raid_disks)
for (i=0; i < cnt-1 ; i++) {
sector_t sz = 0;
int j;
- for (j=i; i<cnt-1 && sz < min_spacing ; j++)
+ for (j = i; j < cnt - 1 && sz < min_spacing; j++)
sz += conf->disks[j].size;
if (sz >= min_spacing && sz < conf->hash_spacing)
conf->hash_spacing = sz;