CVE-2023-53565: 
Linux Kernel vulnerability analysis and mitigation

A vulnerability in the Linux kernel's brcmfmac WiFi driver has been identified and tracked as CVE-2023-53565. The issue involves a NULL pointer dereference in the probe() function when handling id arguments, discovered on October 4, 2025. This vulnerability affects the brcmfmac driver's handling of device probing during system resume and manual driver binding operations (NVD, RedHat).

The vulnerability occurs in two specific scenarios: 1) when brcmfpciepmleaveD3() calls brcmfpcieprobe() to reprobe the device, and 2) when a user attempts to manually bind the driver from sysfs, causing the sdio/pcie/usb probe() function to be called with a NULL id argument. The issue has been assigned a CVSS v3.1 score of 5.3, indicating moderate severity, with attack vector metrics of AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H (RedHat).

When exploited, this vulnerability causes a kernel NULL pointer dereference at address 0x18, leading to system instability and WiFi functionality failure. The issue manifests as a kernel oops on system resume, effectively disrupting wireless connectivity on affected systems (NVD).

The fix involves implementing a check for NULL id arguments in the probe function. For PCI and USB cases, a manual lookup of the id is implemented to ensure proper functionality during sysfs binding and resume operations. For SDIO cases, the system is configured to error out when encountering a NULL id, as no manual sdiodeviceid lookup helper is available (NVD).