Re: KASAN: use-after-free Read in ethnl_update_bitset32

[syzbot]

syzbot has bisected this bug to:

commit bfbcfe2032e70bd8598d680d39ac177d507e39ac
Author: Michal Kubecek <mkubecek@xxxxxxx>
Date:   Fri Dec 27 14:56:13 2019 +0000

    ethtool: set link modes related data with LINKMODES_SET request

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=16d59109e00000
start commit:   0c0ddd6a Merge tag 'linux-watchdog-5.6-rc3' of git://www.l..
git tree:       net
final crash:    https://syzkaller.appspot.com/x/report.txt?x=15d59109e00000
console output: https://syzkaller.appspot.com/x/log.txt?x=11d59109e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=3b8906eb6a7d6028
dashboard link: https://syzkaller.appspot.com/bug?extid=709b7a64d57978247e44
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13885de9e00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1518127ee00000

Reported-by: syzbot+709b7a64d57978247e44@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: bfbcfe2032e7 ("ethtool: set link modes related data with LINKMODES_SET request")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection