CVE-2022-50267: 
Linux Kernel vulnerability analysis and mitigation

CVE-2022-50267 is a memory management vulnerability in the Linux kernel's MMC (MultiMediaCard) driver for Realtek PCI devices (mmc: rtsx_pci). The flaw arises from the driver failing to check the return value of mmc_add_host(), which can result in memory leaks and kernel crashes when the device is removed. It affects Linux kernel versions from 3.8 up to (but not including) 5.15.86, 5.16 through 6.0.15, and 6.1 through 6.1.1. Disclosed on September 15, 2025, it carries a CVSS v3.1 base score of 5.5 (Medium) (Red Hat Advisory, Red Hat Bugzilla).

The root cause is classified as CWE-476 (NULL Pointer Dereference), stemming from improper error handling in the rtsx_pci_sdmmc driver. When mmc_add_host() returns an error, the memory allocated by mmc_alloc_host() is not freed, creating a memory leak. Subsequently, when the device is removed, the kernel attempts to delete a device that was never successfully added, triggering a kernel crash. The fix involves checking the return value of mmc_add_host(), calling mmc_free_host() in the error path, and disabling runtime power management (PM) appropriately (Red Hat Bugzilla, Red Hat Advisory).

Successful exploitation can cause a denial of service through kernel crashes or system instability due to memory leaks in the MMC subsystem. The impact is limited to availability — there is no confidentiality or integrity impact. An attacker with local access to a system using a Realtek PCI MMC device could trigger this condition, potentially causing system downtime (Red Hat Advisory, Red Hat Bugzilla).

There is no known public proof-of-concept exploit and no evidence of in-the-wild exploitation at this time. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. The EPSS score is approximately 0.018%, reflecting a very low probability of exploitation in the near term. Exploitation requires local access and low privileges (Red Hat Advisory).

Patches have been released for multiple Linux kernel stable branches: versions 5.15.86, 6.0.16, 6.1.2, and 6.2 include the fix. Administrators should update to the latest patched kernel version for their distribution. SUSE Linux has issued kernel security advisories (SUSE-2025-03615-1, SUSE-2025-03628-1, SUSE-2025-3716-1) addressing this CVE. No configuration-based workaround is available; upgrading the kernel is the recommended remediation (Red Hat Advisory, SUSE Advisory).