CVE-2023-53274: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-53274 is an out-of-bounds write vulnerability in the Linux kernel's MediaTek MT8183 clock driver (clk: mediatek: mt8183). The flaw was introduced when SSPM (System Security Power Manager) related clocks were removed from the driver, creating holes in the device tree (DT) binding that cause out-of-bounds writes when the driver uses the simple-probe mechanism. It affects Linux kernel versions 6.4 through 6.4.9 and release candidates 6.5-rc1 through 6.5-rc4. The vulnerability was published on September 16, 2025, and carries a CVSS v3.1 base score of 7.8 (High) (Red Hat Advisory, Red Hat Bugzilla).

The root cause is an out-of-bounds write (CWE-787) in the MT8183 clock driver. When commit 860690a93ef23b567f781c1b631623e27190f101 removed SSPM-related clocks, it created index gaps (holes) between the clock driver definitions and the DT binding. The simple-probe mechanism allocates memory based on the number of clocks defined in the driver rather than the highest DT binding index, so when the kernel writes clock data using DT indices, it writes beyond the allocated buffer boundaries. These out-of-bounds writes can silently corrupt adjacent kernel memory, causing crashes in unrelated subsystems or going entirely undetected without KASAN instrumentation. The fix reverts the offending commit and re-adds the SSPM clocks, marking them as always-on since they serve the power management co-processor (Red Hat Bugzilla, Red Hat Advisory).

Successful exploitation by a local low-privileged attacker can result in kernel memory corruption, leading to system crashes, data integrity violations, or potential unauthorized access to sensitive kernel memory regions. The vulnerability has high confidentiality, integrity, and availability impacts, as corrupted kernel memory can affect arbitrary subsystems beyond the clock driver itself. The scope is limited to systems running MediaTek MT8183 hardware with affected kernel versions (Red Hat Advisory, Red Hat Bugzilla).

There is no public proof-of-concept exploit and no evidence of in-the-wild exploitation at this time. The vulnerability requires local low-privileged access to the affected system and is hardware-specific to MediaTek MT8183 platforms. The EPSS score is approximately 0.018% (0.000180), indicating a very low probability of exploitation in the near term. The CVE is not listed in the CISA Known Exploited Vulnerabilities catalog (Red Hat Advisory).

The fix is available in Linux kernel version 6.4.10 and the 6.5 stable release, which re-add the SSPM-related clocks to the MT8183 clock driver. Administrators should update to kernel 6.4.10 or later, or apply the upstream patches available at the kernel stable tree (commits 1eb8d61ac5c9c7ec56bb96d433532807509b9288 and 45d69917a4af6c869193f95932dc6d6f15d5ef86). SUSE has also issued kernel advisories addressing this CVE. As a detection measure, enabling KASAN (Kernel Address Sanitizer) on affected systems can help identify out-of-bounds write attempts. Restricting local user access on MT8183-based systems reduces exposure until patching is complete (Red Hat Bugzilla, SUSE Advisory).