Re: KASAN: use-after-free Read in p9_fd_poll

syzbot suspects this bug was fixed by commit:

commit 430ac66eb4c5b5c4eb846b78ebf65747510b30f1
Author: Tomas Bortoli [off-list ref]
Date:   Fri Jul 20 09:27:30 2018 +0000

     net/9p/trans_fd.c: fix race-condition by flushing workqueue before the  
kfree()

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=1646690c600000
start commit:   d72e90f3 Linux 4.18-rc6
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=68af3495408deac5
dashboard link: https://syzkaller.appspot.com/bug?extid=0442e6e2f7e1e33b1037
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1569b51c400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16e7a978400000

If the result looks correct, please mark the bug fixed by replying with:

#syz fix: net/9p/trans_fd.c: fix race-condition by flushing workqueue  
before the kfree()

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