Fix the refcounting problem

Oct 13, 2025 by wbrum.org 58 views

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Introduction

Updating the firmware of a device can be a complex process, especially when it involves kernel modules and device drivers. In this article, we will explore a specific issue that occurs when updating the CVS firmware on a Dell ARL-based laptop. We will examine the kernel logs and provide possible solutions to resolve the issue.

Background

The CVS firmware update process involves using the fwupd tool to install a new firmware blob on the device. The process involves several steps, including:

Installing the intel-cvs plugin using fwupdtool.
Running the install-blob command with the new firmware blob.
The kernel module loads and the device driver initializes.

However, in this specific case, the kernel module crashes and the device driver fails to initialize, resulting in a kernel oops.

Kernel Logs

The kernel logs provide valuable information about the crash. Here are the relevant logs:

[ 4704.583198] usbio-bridge 3-4:1.0: bridge write failed ret:-110 total_len:0
[ 4704.583223] ------------[ cut here ]------------
[ 4704.583225] kernel BUG at mm/slub.c:547!
[ 4704.583239] Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[ 4704.583246] CPU: 1 UID: 0 PID: 8040 Comm: fwupdtool Tainted: G        W  OE      6.12.9-200.fc41.x86_64 #1
[ 4704.583254] Tainted: [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
[ 4704.583256] Hardware name: REDACTED
[ 4704.583260] RIP: 0010:kfree+0x2f0/0x360
[ 4704.583271] Code: 5d 41 5e 41 5f 5d e9 0f d6 ff ff 4d 89 f1 41 b8 01 00 00 00 48 89 d9 48 89 da 4c 89 e6 4c 89 ef e8 a5 f7 ff ff e9 34 fe ff ff <0f> 0b 89 c8 4c 8d 04 03 40 f6 c6 80 0f 84 46 ff ff ff 83 e6 08 0f
[ 4704.583275] RSP: 0018:ffffa65ae85d3820 EFLAGS: 00010246
[ 4704.583280] RAX: ffff9aa5c443a180 RBX: ffff9aa5c443a180 RCX: ffff9aa5c443a188
[ 4704.583283] RDX: 0000000033006001 RSI: ffffffffc0e37334 RDI: ffff9aa5c443a180
[ 4704.583286] RBP: ffffa65ae85d3870 R08: 0000000000000000 R09: 0000000000000000
[ 4704.583288] R10: 000000000000000b R11: 0000000000000000 R12: ffffcdb844110e80
[ 4704.583291] R13: ffff9aa5c004ba00 R14: ffffffffc0e37334 R15: 000000000000000b
[ 4704.583294] FS:  00007f52d43c0b80(0000) GS:ffff9ab50fc80000(0000) knlGS:0000000000000000
[ 4704.583303] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4704.583307] CR2: 00007f28b19fe000 CR3: 00000001e035c003 CR4: 0000000000f72ef0
[ 4704.583311] PKRU: 55555554
[ 4717.872431] usbio-bridge 3-4:1.0: header->cmd:2 != stub->cur_cmd:1
[ 4717.872443] usbio-bridge 3-4:1.0: failed to parse data: ret:-22 type:4 len: 6

Analysis

The kernel logs indicate that the kernel module crashes due to an invalid opcode error. The error occurs in the kfree function, which is responsible for freeing memory. The error is likely caused by a refcounting problem, where the kernel module fails to properly release memory.

The logs also indicate that the usbio-bridge driver fails to parse data, resulting in a failure to initialize the device driver.

Possible Solutions

Based on the analysis, the following possible solutions can be considered:

Update the kernel module: The kernel module may be outdated or buggy, causing the crash. Updating the kernel module to the latest version may resolve the issue.
Fix the refcounting problem: The refcounting problem may be caused by a bug in the kernel module. Fixing the bug may resolve the issue.
Disable the usbio-bridge driver: Disabling the usbio-bridge driver may prevent the crash from occurring.
Use a different firmware update tool: Using a different firmware update tool, such as fwupdate, may resolve the issue.

Conclusion

The kernel oops when updating the CVS firmware on a Dell ARL-based laptop is likely caused by a refcounting problem in the kernel module. Updating the kernel module, fixing the refcounting problem, disabling the usbio-bridge driver, or using a different firmware update tool may resolve the issue.

Additional Information

The intel-cvs plugin is used to update the CVS firmware.
The fwupd tool is used to install the new firmware blob.
The kernel module crashes due to an invalid opcode error.
The usbio-bridge driver fails to parse data, resulting in a failure to initialize the device driver.

References

[1] fwupd documentation: https://docs.fwupd.org/
[2] intel-cvs plugin documentation: https://docs.intel.com/content/www/us/en/developer-tools/intel-cvs-plugin.html
[3] Kernel module documentation: https://www.kernel.org/doc/html/latest/modules.html

Introduction

In our previous article, we explored the issue of kernel oops when updating the CVS firmware on a Dell ARL-based laptop. We analyzed the kernel logs and identified possible solutions to resolve the issue. In this article, we will provide a Q&A section to address common questions and concerns related to this issue.

Q: What is the CVS firmware update process?

A: The CVS firmware update process involves using the fwupd tool to install a new firmware blob on the device. The process involves several steps, including installing the intel-cvs plugin, running the install-blob command with the new firmware blob, and loading the kernel module.

Q: What is the kernel module that crashes during the CVS firmware update process?

A: The kernel module that crashes during the CVS firmware update process is the usbio-bridge driver. This driver is responsible for communicating with the device and updating the firmware.

Q: What is the cause of the kernel oops during the CVS firmware update process?

A: The kernel oops during the CVS firmware update process is likely caused by a refcounting problem in the kernel module. This problem may be caused by a bug in the kernel module or a mismatch between the kernel module and the device firmware.

Q: How can I update the kernel module to resolve the issue?

A: To update the kernel module, you can use the fwupd tool to install the latest version of the intel-cvs plugin. You can also check the kernel module documentation for instructions on how to update the module manually.

Q: How can I fix the refcounting problem in the kernel module?

A: To fix the refcounting problem in the kernel module, you can try updating the kernel module to the latest version or patching the module to resolve the issue. You can also try disabling the usbio-bridge driver to prevent the crash from occurring.

Q: What are the possible solutions to resolve the issue?

A: The possible solutions to resolve the issue include:

Updating the kernel module to the latest version
Fixing the refcounting problem in the kernel module
Disabling the usbio-bridge driver
Using a different firmware update tool, such as fwupdate

Q: How can I prevent the kernel oops from occurring during the CVS firmware update process?

A: To prevent the kernel oops from occurring during the CVS firmware update process, you can try the following:

Update the kernel module to the latest version
Fix the refcounting problem in the kernel module
Disable the usbio-bridge driver
Use a different firmware update tool, such as fwupdate

Q: What are the consequences of the kernel oops during the CVS firmware update process?

A: The consequences of the kernel oops during the CVS firmware update process may include:

Device failure
Data loss
System instability
Kernel crashes

Q: How can I recover from a kernel oops during the CVS firmware update process?

A: To recover from a kernel oops during the CVS firmware update process, you can try the following:

Reboot the system
Run the fwupd tool to reinstall the firmware
Update the kernel module to the latest version
Disable the usbio-bridge driver

Conclusion

The kernel oops when updating the CVS firmware on a Dell ARL-based laptop is a complex issue that requires careful analysis and troubleshooting. By understanding the possible causes and solutions to this issue, you can take steps to prevent the kernel oops from occurring and ensure a successful firmware update process.

Additional Information

The intel-cvs plugin is used to update the CVS firmware.
The fwupd tool is used to install the new firmware blob.
The kernel module crashes due to an invalid opcode error.
The usbio-bridge driver fails to parse data, resulting in a failure to initialize the device driver.

References

[1] fwupd documentation: https://docs.fwupd.org/
[2] intel-cvs plugin documentation: https://docs.intel.com/content/www/us/en/developer-tools/intel-cvs-plugin.html
[3] Kernel module documentation: https://www.kernel.org/doc/html/latest/modules.html