Re: INFO: task hung in tls_sw_release_resources_tx

[+Steffen, who is the maintainer of pcrypt]

On Fri, Aug 16, 2019 at 07:02:34PM -0700, Jakub Kicinski wrote:

On Thu, 15 Aug 2019 11:06:00 -0700, syzbot wrote:

quoted

syzbot has bisected this bug to:

commit 130b392c6cd6b2aed1b7eb32253d4920babb4891
Author: Dave Watson [off-list ref]
Date:   Wed Jan 30 21:58:31 2019 +0000

     net: tls: Add tls 1.3 support

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=118e8dee600000
start commit:   6d5afe20 sctp: fix memleak in sctp_send_reset_streams
git tree:       net
final crash:    https://syzkaller.appspot.com/x/report.txt?x=138e8dee600000
console output: https://syzkaller.appspot.com/x/log.txt?x=158e8dee600000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a4c9e9f08e9e8960
dashboard link: https://syzkaller.appspot.com/bug?extid=6a9ff159672dfbb41c95
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17cb0502600000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14d5dc22600000

Reported-by: syzbot+6a9ff159672dfbb41c95@syzkaller.appspotmail.com
Fixes: 130b392c6cd6 ("net: tls: Add tls 1.3 support")

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

CC Herbert, linux-crypto

This is got to be something in the crypto code :S 

The test case opens a ktls socket and back log writes to it.
Then it opens a AF_ALG socket, binds "pcrypt(gcm(aes))" and dies.

The ktls socket upon close waits for async crypto callbacks, but they
never come. If I unset CRYPTO_USER_API_AEAD or change the alg to bind
to "gcm(aes)" the bug does not trigger.

Any suggestions?

Seeing as pcrypt is involved and this is a "task hung" bug, this is probably
caused by the recursive pcrypt deadlock, which is yet to be fixed.

See the original thread for more info:

	https://groups.google.com/forum/#!msg/syzkaller-bugs/1_CXUd3gBcg/BvsRLH0lAgAJ

And the syzbot dashboard link:

	https://syzkaller.appspot.com/bug?id=178f2528d10720d563091fb51dceb4cb20f75525

Let's tell syzbot this is a duplicate:

#syz dup: INFO: task hung in aead_recvmsg


Steffen, do you have any plan to fix this?

- Eric