Re: INFO: task hung in request_key_tag

From: Luis Chamberlain
Date: Wed Jul 01 2020 - 08:20:35 EST


On Wed, Jul 01, 2020 at 07:04:15PM +0900, Tetsuo Handa wrote:
> I suspect commit 9e9b47d6bbe9df65 ("umh: fix processed error when UMH_WAIT_PROC is used").
> Maybe the change in kernel/umh.c and/or security/keys/request_key.c made by that commit is
> affecting call_usermodehelper_keys() == 0 case when complete_request_key() is called.

That patch has been dropped for now due to another reported issue
bisected to it and even though we have not root caused that issue [0].

It would be good to have a reproducer for this reported issue as well,
but I should also point out a regression which Naresh reported is fixed
recently by a posted patch [1] by Herbert Xu. It would be good if you
can test with that patch posted by Herbert.

[0] https://lkml.kernel.org/r/20200623141157.5409-1-borntraeger@xxxxxxxxxx
[1] https://lkml.kernel.org/r/20200626062948.GA25285@xxxxxxxxxxxxxxxxxxx

Luis

>
> On 2020/07/01 16:53, syzbot wrote:
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit: c28e58ee Add linux-next specific files for 20200629
> > git tree: linux-next
> > console output: https://syzkaller.appspot.com/x/log.txt?x=17925a9d100000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=dcd26bbca17dd1db
> > dashboard link: https://syzkaller.appspot.com/bug?extid=46c77dc7e98c732de754
> > compiler: gcc (GCC) 10.1.0-syz 20200507
> >
> > Unfortunately, I don't have any reproducer for this crash yet.
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+46c77dc7e98c732de754@xxxxxxxxxxxxxxxxxxxxxxxxx