From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
To: qiang.zhang@windriver.com, gregkh@linuxfoundation.org,
oneukum@suse.com, lee.jones@linaro.org
Cc: linux-usb@vger.kernel.org
Subject: Re: [PATCH] USB: cdc-wdm: Fix ODEBUG bug in wdm_disconnect
Date: Tue, 11 May 2021 14:48:06 +0900 [thread overview]
Message-ID: <0e4131c7-0372-53cb-74a3-13d3a58ba25c@i-love.sakura.ne.jp> (raw)
In-Reply-To: <20210511033140.29658-1-qiang.zhang@windriver.com>
On 2021/05/11 12:31, qiang.zhang@windriver.com wrote:
> This warning is generated because when kfree wdm_device,
> it is found that there is still an active work in workqueue,
> This phenomenon may be due to the following reasons.
> when the devices disconnect, although the work was cancelled,
> but the schedule_work still may be called, therefore, before
> scheduling work, we need to detect the status of the device.
>
> Reported-by: syzbot <syzbot+7da71853830ac3289474@syzkaller.appspotmail.com>
> Signed-off-by: Zqiang <qiang.zhang@windriver.com>
> ---
> drivers/usb/class/cdc-wdm.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
>
Oliver Neukum is aware of this problem, and is considering poisoning approach than
checking WDM_SUSPENDING/WDM_RESETTING/WDM_DISCONNECTING approach. I guess we could
replace three test_bit() tests into OR'ed-bits test (something like test_bits()) ?
https://lkml.kernel.org/r/2db36d52015b644cc1891fcffc87ef09c2b728b7.camel@suse.com
Oliver, how do we want to fix this problem?
next prev parent reply other threads:[~2021-05-11 5:48 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-11 3:31 [PATCH] USB: cdc-wdm: Fix ODEBUG bug in wdm_disconnect qiang.zhang
2021-05-11 5:48 ` Tetsuo Handa [this message]
2021-05-11 8:11 ` Oliver Neukum
2021-05-11 8:50 ` Greg KH
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