CVE-2026-74269

A flaw was found in the bnxt driver, a component of the Linux kernel responsible for network card operations. This vulnerability involves a memory corruption issue that occurs during specific network data processing (XDP head-grow operations). An underflow in the driver's code can lead to incorrect management of memory, potentially resulting in a 'double free' error. If exploited, this could allow an attacker to cause a denial of service, making the system unavailable, or lead to other unpredictable system behavior.

This flaw is rated as Important severity because improper buffer pointer calculations can trigger kernel memory corruption and system crashes, carrying a higher blast radius than Moderate flaws. Exploitation requires the host to possess Broadcom NetXtreme network hardware and actively run attached eXpress Data Path (XDP) programs configured to expand packet headroom. Default installations that do not utilize this specific physical networking hardware or that do not attach XDP programs to bnxt interfaces are not affected.

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.

Prevent the Broadcom NetXtreme network driver from loading if the hardware is not required:

1. Add a configuration rule to disable module loading:

echo "install bnxt_en /bin/true" > /etc/modprobe.d/disable-bnxt_en.conf

2. If the module is currently loaded, unload it:

modprobe -r bnxt_en

Alternatively, ensure that attached eBPF/XDP programs do not perform packet head expansion operations.

Warning: Blacklisting the bnxt_en module will disable all network interfaces reliant on Broadcom NetXtreme devices. If the module is actively in use by network adapters, unloading it will disrupt connectivity, and a system restart will be required for the configuration change to take effect.