CVE-2026-31661

A flaw was found in the Linux kernel's brcmsmac Wi-Fi driver. This vulnerability arises from an incorrect size used during memory deallocation (dma_free_coherent) that does not match the size allocated (dma_alloc_consistent), which may be adjusted for alignment. An attacker could potentially exploit this memory mismatch, leading to memory corruption. This could result in a denial of service or other unpredictable system behavior.

A Moderate impact flaw was found in the Linux kernel's brcmsmac Wi-Fi driver. This memory corruption vulnerability occurs due to an incorrect size being used during memory deallocation, which does not match the original allocation size. Exploitation could lead to a denial of service or other system instability on systems utilizing affected Broadcom wireless hardware.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, prevent the brcmsmac kernel module from loading if it is not required for your system's operation. This can be achieved by blacklisting the module.

To blacklist the brcmsmac module:

1. Create a new file /etc/modprobe.d/blacklist-brcmsmac.conf with the following content:

   blacklist brcmsmac
   

2. Regenerate the initramfs to ensure the blacklist is applied during boot: For RHEL 7:

   dracut -f -v
   

   For RHEL 8 and 9:

   dracut -f --regenerate-all
   

3. Reboot the system for the changes to take effect.

This mitigation may impact systems relying on Broadcom wireless hardware that uses the brcmsmac driver, as wireless functionality will be disabled. A system reboot is required for the changes to be applied.