Re: INFO: task hung in request_key_tag

On 2020/07/01 21:20, Luis Chamberlain wrote:

On Wed, Jul 01, 2020 at 07:04:15PM +0900, Tetsuo Handa wrote:

quoted

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,

Reproducer is not available yet.
But at least this patch is changing the behavior of

  call_usermodehelper_keys() == 0 && (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags) || key_validate(key) < 0)

case from key_negate_and_link() to key_revoke() in complete_request_key().
Since test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags) might be called from
key_reject_and_link() from key_negate_and_link(), this change might be the cause of
this hung task report.