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: ac27a0e ("[PATCH] ext4: initial copy of files from ext3") Signed-off-by: Kemeng Shi <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
projectceladon · Oct 29, 2024 · 9473f56 · 9473f56
1 parent acc8f5b
commit 9473f56
Showing 1 changed file with 2 additions and 0 deletions.
diff --git 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