md/raid5: don't index beyond end of array in need_this_block().
When need_this_block probably shouldn't be called when there
are more than 2 failed devices, we really don't want it to try
indexing beyond the end of the failed_num[] of fdev[] arrays.
So limit the loops to at most 2 iterations.
Reported-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 2105e5f..d66ff723 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3304,7 +3304,7 @@
*/
return 0;
- for (i = 0; i < s->failed; i++) {
+ for (i = 0; i < s->failed && i < 2; i++) {
if (fdev[i]->towrite &&
!test_bit(R5_UPTODATE, &fdev[i]->flags) &&
!test_bit(R5_OVERWRITE, &fdev[i]->flags))
@@ -3328,7 +3328,7 @@
sh->sector < sh->raid_conf->mddev->recovery_cp)
/* reconstruct-write isn't being forced */
return 0;
- for (i = 0; i < s->failed; i++) {
+ for (i = 0; i < s->failed && i < 2; i++) {
if (s->failed_num[i] != sh->pd_idx &&
s->failed_num[i] != sh->qd_idx &&
!test_bit(R5_UPTODATE, &fdev[i]->flags) &&