Re: [syzbot] BUG: unable to handle kernel NULL pointer dereference in __tcp_transmit_skb

[syzbot]

syzbot has bisected this issue to:

commit f2f2325ec79970807012dfc9e716cdbb02d9b574
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date:   Fri Feb 4 20:15:46 2022 +0000

    ip6mr: ip6mr_sk_done() can exit early in common cases

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=16299d7b700000
start commit:   36c2e31ad25b net: geneve: add missing netlink policy and s..
git tree:       net-next
final oops:     https://syzkaller.appspot.com/x/report.txt?x=15299d7b700000
console output: https://syzkaller.appspot.com/x/log.txt?x=11299d7b700000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4a15e2288cf165c9
dashboard link: https://syzkaller.appspot.com/bug?extid=090d23ddbd5cd185c2e0
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=171eadbd700000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12cacda3700000

Reported-by: syzbot+090d23ddbd5cd185c2e0@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: f2f2325ec799 ("ip6mr: ip6mr_sk_done() can exit early in common cases")

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