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| author | Andy Isaacson <adi@hexapodia.org> | 2007-03-16 22:38:04 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-03-17 03:25:03 +0100 |
| commit | bed31ed9e1cd71d98ff0bc9212100adee523a10a (patch) | |
| tree | bbba995c877dfc161d0ad5e789be684084e1dfe0 | |
| parent | [PATCH] reduce pnp syslog spam (diff) | |
| download | linux-bed31ed9e1cd71d98ff0bc9212100adee523a10a.tar.xz linux-bed31ed9e1cd71d98ff0bc9212100adee523a10a.zip | |
[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>
| -rw-r--r-- | drivers/md/linear.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/md/linear.c b/drivers/md/linear.c index c625ddb8833d..d5ecd2d53046 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; |