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Message-ID: <4c9a5640-9ebf-db87-fcb0-b076b615e4e4@linuxfoundation.org>
Date:   Thu, 12 Jan 2023 08:13:52 -0700
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Subject: =?UTF-8?Q?Re=3a_kernel_BUG=c2=a0at_mm/usercopy=2ec_when_using_usbip?=
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To:     =?UTF-8?B?U29zdGjDqG5lIEd1w6lkb24=?= <sosthene@nitrokey.com>,
        Valentina Manea <valentina.manea.m@gmail.com>,
        Shuah Khan <shuah@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Robin Krahl <robin@nitrokey.com>,
        Shuah Khan <skhan@linuxfoundation.org>
References: <aa686f98-c9a3-6225-18e8-7ca57678ce4a@nitrokey.com>
From:   Shuah Khan <skhan@linuxfoundation.org>
In-Reply-To: <aa686f98-c9a3-6225-18e8-7ca57678ce4a@nitrokey.com>
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On 1/12/23 01:40, Sosthène Guédon wrote:
> Hi!
> 
> I have stumbled upon a bug that is triggered reliably by using usbip.
> 
> We are using usbip to test our firmware. usbip attach works, but once `opgpcard-tools` interacts with the firmware through pcscd, a kernel bug happens.
> Then usbip stops working, and `lsusb` as well as other tools interacting with usb devices hang.
> The symptoms are similar to https://bugzilla.kernel.org/show_bug.cgi?id=215487 but the kernel bug is not the same (see attached dmesg logs).
> 
> The bug can be reproduced on arch (Linux archlinux 6.1.4-arch1-1 #1 SMP PREEMPT_DYNAMIC Sat, 07 Jan 2023 15:10:07 +0000 x86_64 GNU/Linux
> ) and debian (Linux nitropc 5.10.0-19-amd64 #1 SMP Debian 5.10.149-2 (2022-10-21) x86_64 GNU/Linux), though the reproduction is not minimal.
> 
> To reproduce the bug on Arch Linux, with the packages rust, pcsclite, and openpgp-card-tools installed:
> 
> - Compile and run the usbip runner from this PR: https://github.com/Nitrokey/nitrokey-3-firmware/pull/149 (`cd nitrokey-3-firmware/runners/usbip && cargo run --features alpha`)
> - Run `usbip attach -r localhost -b 1-1`
> - Run `pcscd`
> - Run `opgpcard status`
> 
> The bug should happen.
> 

Thank you for reporting the problem. I will take a look and
get back to you with possible fix. Will you be able to test
fixes?

thanks,
-- Shuah