linux-kernel - Re: [syzbot] [input?] [usb?] [mm?] INFO: rcu detected stall in vma_link

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <a0f21b01-3937-41e5-846d-340df0239e87@I-love.SAKURA.ne.jp>
Date: Wed, 16 Oct 2024 17:30:39 +0900
From: Tetsuo Handa <penguin-kernel@...ove.SAKURA.ne.jp>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
Cc: syzbot <syzbot+ce483fd06e2061f44f5d@...kaller.appspotmail.com>,
        akpm@...ux-foundation.org, liam.howlett@...cle.com,
        linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-mm@...ck.org, linux-usb@...r.kernel.org,
        syzkaller-bugs@...glegroups.com, vbabka@...e.cz,
        Marcello Sylvester Bauer <sylv@...v.io>,
        Jiri Kosina <jikos@...nel.org>,
        Benjamin Tissoires <bentiss@...nel.org>
Subject: Re: [syzbot] [input?] [usb?] [mm?] INFO: rcu detected stall in
 vma_link_file

On 2024/10/16 16:14, Greg Kroah-Hartman wrote:
> On Wed, Oct 16, 2024 at 08:06:20AM +0100, Lorenzo Stoakes wrote:
>> + some people from USB/HID subsystem.
>>
>> This is really not looking mm-related, as for a second time we've asked
>> syzbot to re-run and for a second time it's not hit any mm-specific code -
>> I think this is misattributed - could somebody from the USB/HID side take a
>> look?
>>
>> It looks to be something that isn't reproduced by a specific C program but
>> by a syzkaller USB configuration [0]?
> 
> There's a lot of odd usb syzbot issues right now dealing with the dummy
> hcd controller, so maybe this is another one of them...

This is a printk() flooding stall triggered by SysRq-t.

 sched_show_task+0x3f0/0x5f0 kernel/sched/core.c:7557
 show_state_filter+0xee/0x320 kernel/sched/core.c:7627
 k_spec drivers/tty/vt/keyboard.c:667 [inline]
 k_spec+0xed/0x150 drivers/tty/vt/keyboard.c:656
 kbd_keycode drivers/tty/vt/keyboard.c:1522 [inline]
 kbd_event+0xcbd/0x17a0 drivers/tty/vt/keyboard.c:1541