Re: [syzbot] [bpf?] [trace?] possible deadlock in task_fork_fair

[syzbot]

syzbot has bisected this issue to:

commit a3c06ae158dd6fa8336157c31d9234689d068d02
Author: Parav Pandit <parav@xxxxxxxxxx>
Date:   Tue Jan 5 10:32:03 2021 +0000

    vdpa_sim_net: Add support for user supported devices

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=14c0b21ee80000
start commit:   2ebe81c81435 net, xdp: Allow metadata > 32
git tree:       bpf-next
final oops:     https://syzkaller.appspot.com/x/report.txt?x=16c0b21ee80000
console output: https://syzkaller.appspot.com/x/log.txt?x=12c0b21ee80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f8715b6ede5c4b90
dashboard link: https://syzkaller.appspot.com/bug?extid=1a93ee5d329e97cfbaff
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=148b2632e80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11aae88ee80000

Reported-by: syzbot+1a93ee5d329e97cfbaff@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: a3c06ae158dd ("vdpa_sim_net: Add support for user supported devices")

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