Re: KASAN: slab-out-of-bounds Write in default_read_copy_kernel

[syzbot]

syzbot has bisected this bug to:

commit 65766ee0bf7fe8b3be80e2e1c3ef54ad59b29476
Author: Takashi Iwai <tiwai@xxxxxxx>
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@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 65766ee0 ("ALSA: oss: Use kvzalloc() for local buffer allocations")