From 8885b11fb253e08ecfa90a28beffb01719af84f5 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Thu, 22 Sep 2022 11:09:29 +0200
Subject: [PATCH] ext4: Fixup possible uninitialized variable access in
 ext4_mb_choose_next_group_cr1()

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.

Fixes: 83e80a6e3543 ("ext4: use buckets for cr 1 block scan instead of rbtree")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/mballoc.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 71f5b67d7f28..9dad93059945 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)
-- 
2.35.3

