Re: [syzbot] BUG: sleeping function called from invalid context in __access_remote_vm

From: Tetsuo Handa
Date: Mon Aug 22 2022 - 06:04:45 EST


Caused by commit 38a12ad69d86f801 ("lib/dump_stack: add dump_stack_print_cmdline()
and wire up in dump_stack_print_info()"). You can't call get_task_cmdline_kernel()
from dump_stack() due to printk_cpu_sync_get_irqsave(flags) from dump_stack_lvl().

Andrew, please drop that patch.

On 2022/08/22 18:09, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 8755ae45a9e8 Add linux-next specific files for 20220819
> git tree: linux-next
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=14c3b6eb080000
> kernel config: https://syzkaller.appspot.com/x/.config?x=ead6107a3bbe3c62
> dashboard link: https://syzkaller.appspot.com/bug?extid=5fb61eb0bea5eab81137
> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=166bdb3d080000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16298e5b080000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+5fb61eb0bea5eab81137@xxxxxxxxxxxxxxxxxxxxxxxxx
>