Re: UBSAN: shift-out-of-bounds in ext4_fill_super

[Theodore Y. Ts'o]

On Tue, Dec 08, 2020 at 11:33:11PM -0800, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    15ac8fdb Add linux-next specific files for 20201207
> git tree:       linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=1125c923500000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=3696b8138207d24d
> dashboard link: https://syzkaller.appspot.com/bug?extid=345b75652b1d24227443
> compiler:       gcc (GCC) 10.1.0-syz 20200507
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=151bf86b500000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=139212cb500000

#syz test git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git e360ba58d067a30a4e3e7d55ebdd919885a058d6