[PATCH] ext4: No need to continue when the number of entries is 1

[Edward Adam Davis <eadavis@qq.com>]

When the number of entries mapped is 1, there is no need to split it.

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>
---
 fs/ext4/namei.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index a630b27a4cc6..0a111274dc4a 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2043,7 +2043,7 @@ 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));
-- 
2.43.0