From b4f724c8a90987d4785fd1accfe69c125567be39 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Thu, 24 Jul 2014 22:19:27 -0400 Subject: [PATCH] e2fsck: fix off-by-one bounds check on group number Since fs->group_desc_count is the number of block groups, the number of the last group is always one less than this count. Fix the bounds check to reflect that. This flaw shouldn't have any user-visible side effects, since the block bitmap test based on last_grp later on can handle overbig block numbers. Signed-off-by: Darrick J. Wong Signed-off-by: Theodore Ts'o --- e2fsck/pass1.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c index 7a887de..cf36a08 100644 --- a/e2fsck/pass1.c +++ b/e2fsck/pass1.c @@ -2653,8 +2653,8 @@ static void new_table_block(e2fsck_t ctx, blk64_t first_block, dgrp_t group, first_block = ext2fs_group_first_block2(fs, flexbg_size * flexbg); last_grp = group | (flexbg_size - 1); - if (last_grp > fs->group_desc_count) - last_grp = fs->group_desc_count; + if (last_grp >= fs->group_desc_count) + last_grp = fs->group_desc_count - 1; last_block = ext2fs_group_last_block2(fs, last_grp); } else last_block = ext2fs_group_last_block2(fs, group); -- 1.8.3.1