From: Jan Kara Date: Thu, 22 Sep 2022 09:09:29 +0000 (+0200) Subject: ext4: fixup possible uninitialized variable access in ext4_mb_choose_next_group_cr1() X-Git-Tag: v5.19.12~2 X-Git-Url: http://git.itanic.dy.fi/?p=linux-stable;a=commitdiff_plain;h=cdefe8dd61c9030f74e5f6b549af9ca81ddf561d ext4: fixup possible uninitialized variable access in ext4_mb_choose_next_group_cr1() commit a078dff870136090b5779ca2831870a6c5539d36 upstream. Variable 'grp' may be left uninitialized if there's no group with suitable average fragment size (or larger). Fix the problem by initializing it earlier. Link: https://lore.kernel.org/r/20220922091542.pkhedytey7wzp5fi@quack3 Fixes: 83e80a6e3543 ("ext4: use buckets for cr 1 block scan instead of rbtree") Cc: stable@kernel.org Reported-by: Dan Carpenter Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index bf4ec1c06572..fd29e15d1c3b 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -910,7 +910,7 @@ static void ext4_mb_choose_next_group_cr1(struct ext4_allocation_context *ac, int *new_cr, ext4_group_t *group, ext4_group_t ngroups) { struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); - struct ext4_group_info *grp, *iter; + struct ext4_group_info *grp = NULL, *iter; int i; if (unlikely(ac->ac_flags & EXT4_MB_CR1_OPTIMIZED)) { @@ -927,7 +927,6 @@ static void ext4_mb_choose_next_group_cr1(struct ext4_allocation_context *ac, read_unlock(&sbi->s_mb_avg_fragment_size_locks[i]); continue; } - grp = NULL; list_for_each_entry(iter, &sbi->s_mb_avg_fragment_size[i], bb_avg_fragment_size_node) { if (sbi->s_mb_stats)