Re: KASAN: use-after-free Read in btrfs_scan_one_device

From: David Sterba
Date: Wed Sep 30 2020 - 12:59:19 EST


On Sun, Sep 20, 2020 at 07:12:14AM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: eb5f95f1 Merge tag 's390-5.9-6' of git://git.kernel.org/pu..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=10a0a8bb900000
> kernel config: https://syzkaller.appspot.com/x/.config?x=ffe85b197a57c180
> dashboard link: https://syzkaller.appspot.com/bug?extid=582e66e5edf36a22c7b0
> compiler: gcc (GCC) 10.1.0-syz 20200507
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+582e66e5edf36a22c7b0@xxxxxxxxxxxxxxxxxxxxxxxxx

#syz fix: btrfs: fix overflow when copying corrupt csums for a message