diff options
| author | Andy Isaacson <adi@hexapodia.org> | 2007-03-26 23:42:40 +0200 |
|---|---|---|
| committer | Adrian Bunk <bunk@stusta.de> | 2007-03-26 23:42:40 +0200 |
| commit | 36c8a3d3ac8b0157ea4ebc54926d40309787a865 (patch) | |
| tree | 63032fe4124bc951f8ba92b1c55c54c9ccdbf152 /drivers | |
| parent | 6b9720b5aca01aba1fb9403f1b75bb26689223a1 (diff) | |
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
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Diffstat (limited to 'drivers')
| -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 777585458c8..0fa9e685578 100644 --- a/drivers/md/linear.c +++ b/drivers/md/linear.c @@ -174,7 +174,7 @@ static int linear_run (mddev_t *mddev) 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; |