Re: INFO: task hung in __flush_work

syzbot has bisected this bug to:

commit a42055e8d2c30d4decfc13ce943d09c7b9dad221
Author: Vakul Garg [off-list ref]
Date:   Fri Sep 21 04:16:13 2018 +0000

     net/tls: Add support for async encryption of records for performance

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=11bf7ecae00000
start commit:   90cadbbf Merge git://git.kernel.org/pub/scm/linux/kernel/g..
git tree:       net-next
final crash:    https://syzkaller.appspot.com/x/report.txt?x=13bf7ecae00000
console output: https://syzkaller.appspot.com/x/log.txt?x=15bf7ecae00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9d41c8529d7e7362
dashboard link: https://syzkaller.appspot.com/bug?extid=aa0b64a57e300a1c6bcc
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12a6629b400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1222d29b400000

Reported-by: syzbot+aa0b64a57e300a1c6bcc@syzkaller.appspotmail.com
Fixes: a42055e8d2c3 ("net/tls: Add support for async encryption of records  
for performance")

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