[alsa-devel] KASAN: slab-out-of-bounds Write in default_read_copy_kernel

[Takashi Iwai]

On Sat, 16 Mar 2019 15:49:02 +0100,
syzbot wrote:
> 
> syzbot has bisected this bug to:
> 
> commit 65766ee0bf7fe8b3be80e2e1c3ef54ad59b29476
> Author: Takashi Iwai <tiwai at suse.de>
> Date:   Fri Nov 9 10:59:45 2018 +0000
> 
>     ALSA: oss: Use kvzalloc() for local buffer allocations
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=13ae57db200000
> start commit:   65766ee0 ALSA: oss: Use kvzalloc() for local buffer alloca..
> git tree:       upstream
> final crash:    https://syzkaller.appspot.com/x/report.txt?x=106e57db200000
> console output: https://syzkaller.appspot.com/x/log.txt?x=17ae57db200000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=b9cc5a440391cbfd
> dashboard link: https://syzkaller.appspot.com/bug?extid=12f17c177de05efea72d
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16c27125400000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=152a2a43400000
> 
> Reported-by: syzbot+12f17c177de05efea72d at syzkaller.appspotmail.com
> Fixes: 65766ee0 ("ALSA: oss: Use kvzalloc() for local buffer allocations")

This commit itself is no cause, but it's merely a change allowing
finer memory tracking.


thanks,

Takashi