Re: general protection fault in syscall_return_slowpath

[Andy Lutomirski]

On Sat, Mar 7, 2020 at 11:45 PM syzbot
<syzbot+cd66e43794b178bb5cd6@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit:    63623fd4 Merge tag 'for-linus' of git://git.kernel.org/pub..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=16cfeac3e00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=5d2e033af114153f
> dashboard link: https://syzkaller.appspot.com/bug?extid=cd66e43794b178bb5cd6
> compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12a42329e00000
>

I bet this is due to entirely missing input validation in
con_font_copy() and/or fbcon_copy_font().