From cea8e2a46971146f5ab840ed48cf84acf892006c Mon Sep 17 00:00:00 2001
From: Kemeng Shi <shikemeng@huaweicloud.com>
Date: Tue, 20 Aug 2024 21:22:30 +0800
Subject: [PATCH] ext4: avoid negative min_clusters in find_group_orlov()
[ Upstream commit bb0a12c3439b10d88412fd3102df5b9a6e3cd6dc ]
min_clusters is signed integer and will be converted to unsigned
integer when compared with unsigned number stats.free_clusters.
If min_clusters is negative, it will be converted to a huge unsigned
value in which case all groups may not meet the actual desired free
clusters.
Set negative min_clusters to 0 to avoid unexpected behavior.
Fixes: ac27a0ec112a ("[PATCH] ext4: initial copy of files from ext3")
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://patch.msgid.link/20240820132234.2759926-4-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/ext4/ialloc.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 99e8852c4e1dd..8a8d802275608 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -514,6 +514,8 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent,
if (min_inodes < 1)
min_inodes = 1;
min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
+ if (min_clusters < 0)
+ min_clusters = 0;
/*
* Start looking in the flex group where we last allocated an
--
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