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.
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+46c77dc7e98c732de...@syzkaller.appspotmail.com