From: Edward Adam Davis <eadavis@qq.com>
Date: Mon, 1 Jul 2024 14:25:03 +0000 (+0800)
Subject: ext4: no need to continue when the number of entries is 1
X-Git-Tag: v6.12-rc1~117^2~85
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1a00a393d6a7fb1e745a41edd09019bd6a0ad64c;p=thirdparty%2Fkernel%2Flinux.git

ext4: no need to continue when the number of entries is 1

Fixes: ac27a0ec112a ("[PATCH] ext4: initial copy of files from ext3")
Reported-by: syzbot+ae688d469e36fb5138d0@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=ae688d469e36fb5138d0
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Reported-and-tested-by: syzbot+ae688d469e36fb5138d0@syzkaller.appspotmail.com
Link: https://patch.msgid.link/tencent_BE7AEE6C7C2D216CB8949CE8E6EE7ECC2C0A@qq.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
---

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 6a95713f9193b..1de1c1b460a76 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1999,7 +1999,7 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 		split = count/2;
 
 	hash2 = map[split].hash;
-	continued = hash2 == map[split - 1].hash;
+	continued = split > 0 ? hash2 == map[split - 1].hash : 0;
 	dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
 			(unsigned long)dx_get_block(frame->at),
 					hash2, split, count-split));