CVE-2026-53115: 
Linux Kernel vulnerability analysis and mitigation

CVE-2026-53115 is a use-after-free (UAF) vulnerability in the Linux kernel's fsl-mc (Freescale Management Complex) bus driver, caused by improper resource locking during driver probing. When a driver is probed via __driver_attach(), the bus match() callback is invoked without the device lock held, allowing unsynchronized access to the driver_override field and creating a UAF condition. The vulnerability affects Linux kernel versions from 5.10 up to (but not including) the patched releases: 6.12.91, 6.18.33, 7.0.10, and 7.1. It was published on June 24, 2026, with a CVSS v3.1 base score of 5.5 (Medium) (GitHub Advisory, Red Hat Bugzilla).

The root cause is classified as CWE-413 (Improper Resource Locking). In the fsl-mc bus driver, the match() callback is called from __driver_attach() without holding the device lock — a design choice that is intentional in the driver core — but the fsl-mc implementation directly accesses the driver_override field during this unlocked window, creating a race condition that can result in a use-after-free. The fix migrates the driver to use the generic driver-core driver_override infrastructure, which handles proper locking internally, eliminating the unsynchronized access. The attack vector is local, requiring low privileges, and no user interaction (GitHub Advisory, Red Hat Bugzilla).

A local user with the ability to trigger driver probing on the fsl-mc bus can exploit the UAF condition to potentially execute arbitrary code with kernel privileges, leading to full system compromise. The primary impact is on availability (rated High), with no direct confidentiality or integrity impact per the CVSS scoring, though kernel-level code execution in practice could enable privilege escalation and broader system control. The scope is limited to the affected host; lateral movement would require additional exploitation steps (GitHub Advisory, Red Hat Bugzilla).

Apply the upstream kernel patches that migrate the fsl-mc bus driver to use the generic driver-core driver_override infrastructure. Fixed versions include Linux kernel 6.12.91, 6.18.33, 7.0.10, and 7.1. The relevant upstream commits are 4911b836f35c, 8139ce66b52a, 60bfb563a399, and 6c8dfb036273. Organizations running affected kernels on NXP/Freescale SoC-based hardware should prioritize upgrading to a patched kernel version; no configuration-based workaround is documented (GitHub Advisory, Red Hat Bugzilla).