Re: INFO: task hung in fb_open

From: Daniel Vetter
Date: Thu Dec 05 2019 - 09:05:10 EST


On Thu, Dec 5, 2019 at 2:38 PM syzbot
<syzbot+a4ae1442ccc637162dc1@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> syzbot has bisected this bug to:
>
> commit 979c11ef39cee79d6f556091a357890962be2580
> Author: Ayan Kumar Halder <ayan.halder@xxxxxxx>
> Date: Tue Jul 17 17:13:46 2018 +0000
>
> drm/sun4i: Substitute sun4i_backend_format_is_yuv() with format->is_yuv

Pretty sure your GCD machine is not using the sun4i driver. It's also
very far away from the code that's blowing up. bisect gone wrong?
-Daniel

>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=15d2f97ee00000
> start commit: 596cf45c Merge branch 'akpm' (patches from Andrew)
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=13d2f97ee00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=7d8ab2e0e09c2a82
> dashboard link: https://syzkaller.appspot.com/bug?extid=a4ae1442ccc637162dc1
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14273edae00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15e7677ae00000
>
> Reported-by: syzbot+a4ae1442ccc637162dc1@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: 979c11ef39ce ("drm/sun4i: Substitute sun4i_backend_format_is_yuv()
> with format->is_yuv")
>
> 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