WARNING in drm_mode_createblob_ioctl

[Daniel Vetter]

On Wed, Nov 6, 2019 at 4:20 PM syzbot
<syzbot+fb77e97ebf0612ee6914 at syzkaller.appspotmail.com> wrote:
>
> syzbot has bisected this bug to:
>
> commit 9e5a64c71b2f70ba530f8156046dd7dfb8a7a0ba
> Author: Kees Cook <keescook at chromium.org>
> Date:   Mon Nov 4 22:57:23 2019 +0000
>
>      uaccess: disallow > INT_MAX copy sizes

Ah cool, this explains it.

fwiw I never managed to get the WARNING in the backtrace to lign up
with any code. No idea what's been going on.

I'll type a patch to paper over this.
-Daniel

>
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=125fe6dce00000
> start commit:   51309b9d Add linux-next specific files for 20191105
> git tree:       linux-next
> final crash:    https://syzkaller.appspot.com/x/report.txt?x=115fe6dce00000
> console output: https://syzkaller.appspot.com/x/log.txt?x=165fe6dce00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=a9b1a641c1f1fc52
> dashboard link: https://syzkaller.appspot.com/bug?extid=fb77e97ebf0612ee6914
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1212dc3ae00000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=145f604ae00000
>
> Reported-by: syzbot+fb77e97ebf0612ee6914 at syzkaller.appspotmail.com
> Fixes: 9e5a64c71b2f ("uaccess: disallow > INT_MAX copy sizes")
>
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection



-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch