4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Edward Adam Davis <eadavis@xxxxxx>
commit 1a00a393d6a7fb1e745a41edd09019bd6a0ad64c upstream.
Fixes: ac27a0ec112a ("[PATCH] ext4: initial copy of files from ext3")
Reported-by: syzbot+ae688d469e36fb5138d0@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=ae688d469e36fb5138d0
Signed-off-by: Edward Adam Davis <eadavis@xxxxxx>
Reported-and-tested-by: syzbot+ae688d469e36fb5138d0@xxxxxxxxxxxxxxxxxxxxxxxxx
Link: https://patch.msgid.link/tencent_BE7AEE6C7C2D216CB8949CE8E6EE7ECC2C0A@xxxxxx
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Cc: stable@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ext4/namei.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1832,7 +1832,7 @@ static struct ext4_dir_entry_2 *do_split
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));
