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)); Patches currently in stable-queue which might be from eadavis@xxxxxx are queue-4.19/jfs-check-if-leafidx-greater-than-num-leaves-per-dma.patch queue-4.19/jfs-fix-uaf-in-dbfreebits.patch queue-4.19/ext4-no-need-to-continue-when-the-number-of-entries-is-1.patch