Re: [syzbot] [bpf?] possible deadlock in trie_delete_elem

[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=1626def1180000
start commit:   f6e922365faf xsk: Don't assume metadata is always requeste..
git tree:       bpf
final oops:     https://syzkaller.appspot.com/x/report.txt?x=1526def1180000
console output: https://syzkaller.appspot.com/x/log.txt?x=1126def1180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=6fb1be60a193d440
dashboard link: https://syzkaller.appspot.com/bug?extid=9d95beb2a3c260622518
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14115c6e180000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=124fd231180000

Reported-by: syzbot+9d95beb2a3c260622518@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: a3c06ae158dd ("vdpa_sim_net: Add support for user supported devices")

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