CVE-2026-43015
Use-After-Free in Linux Kernel macb Driver
Publication date: 2026-05-01
Last updated on: 2026-05-01
Assigner: kernel.org
Description
Description
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux_kernel | linux_kernel | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in the Linux kernel's macb network driver related to improper handling of clock (clk) resources during the removal of PCI glue drivers. Specifically, when a platform device is unregistered, the runtime resume callback may still attempt to use clock pointers that have already been freed, leading to a use-after-free bug.
The issue arises because pointers to clocks are not saved locally before the platform device is unregistered, causing the runtime resume function to access invalid memory. This bug was previously addressed in a different part of the code but was moved rather than fully fixed. The fix involves saving the clock pointers into local variables for safe reuse after the device is unregistered.
How can this vulnerability impact me? :
This vulnerability can lead to a use-after-free condition in the Linux kernel, which may cause system instability, crashes, or potential kernel memory corruption. Such issues can result in denial of service or unpredictable behavior of the affected system.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability is related to a use-after-free bug in the Linux kernel's macb network driver during PCI glue driver removal, which may cause kernel crashes or memory corruption.
Detection would typically involve monitoring kernel logs for KASAN (Kernel Address Sanitizer) reports indicating use-after-free errors related to clk_prepare or macb_runtime_resume functions.
You can check your kernel logs for such errors using commands like:
- dmesg | grep -i kasan
- journalctl -k | grep -i kasan
- grep -i 'use-after-free' /var/log/kern.log
Additionally, checking for the presence of the affected macb driver and kernel version may help identify if the system is vulnerable.
What immediate steps should I take to mitigate this vulnerability?
The primary mitigation is to update the Linux kernel to a version where this vulnerability has been fixed.
Since the issue is fixed by saving pointers to clocks into local variables before platform device unregistration, applying the patch or upgrading to kernel version 6.1.164+ or later that includes this fix is recommended.
Until the update can be applied, avoid removing or unloading the macb PCI driver module to prevent triggering the use-after-free condition.
Monitoring system stability and kernel logs for related errors can also help in early detection of exploitation attempts.