From 36707bb2e7c6730d79d6cdc6d1475d3d7e94c518 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 24 Sep 2015 15:25:36 +1000 Subject: [PATCH] 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 Signed-off-by: NeilBrown --- drivers/md/raid5.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 2105e5f1fd31..d66ff723df45 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -3304,7 +3304,7 @@ static int need_this_block(struct stripe_head *sh, struct stripe_head_state *s, */ 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 @@ static int need_this_block(struct stripe_head *sh, struct stripe_head_state *s, 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) && -- 2.11.0