Re: KASAN: unknown-crash Read in do_exit

From: Dmitry Vyukov
Date: Tue Oct 20 2020 - 02:11:51 EST


On Mon, Oct 19, 2020 at 11:38 PM syzbot
<syzbot+d9ae84069cff753e94bf@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> syzbot suspects this issue was fixed by commit:
>
> commit a49145acfb975d921464b84fe00279f99827d816
> Author: George Kennedy <george.kennedy@xxxxxxxxxx>
> Date: Tue Jul 7 19:26:03 2020 +0000
>
> fbmem: add margin check to fb_check_caps()
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=17ce19c8500000
> start commit: 729e3d09 Merge tag 'ceph-for-5.9-rc5' of git://github.com/..
> git tree: upstream
> kernel config: https://syzkaller.appspot.com/x/.config?x=c61610091f4ca8c4
> dashboard link: https://syzkaller.appspot.com/bug?extid=d9ae84069cff753e94bf
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10642545900000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=141f2bed900000
>
> If the result looks correct, please mark the issue as fixed by replying with:
>
> #syz fix: fbmem: add margin check to fb_check_caps()
>
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Based on the reproducer it looks reasonable:

#syz fix: fbmem: add margin check to fb_check_caps()