CVE-2022-50138: 
Linux Kernel vulnerability analysis and mitigation

CVE-2022-50138 is a memory leak vulnerability in the Linux kernel's RDMA/qedr module, specifically in the __qedr_alloc_mr() function. When rdma_alloc_tid() or rdma_register_tid() fail, the memory allocated for mr->info.pbl_table via init_mr_info() is not released before the mr structure is freed, resulting in a kernel memory leak. The vulnerability affects Linux kernel versions 4.9 through 5.10.136, 5.11 through 5.15.60, 5.16 through 5.18.17, and 5.19 through 5.19.1. It was published on June 18, 2025, and carries a CVSS v3.1 base score of 5.5 (Medium) (Feedly, Kernel Patches).

The root cause is classified as CWE-401 (Missing Release of Memory after Effective Lifetime). In __qedr_alloc_mr(), the function calls init_mr_info() to allocate a page block list (PBL) table for mr->info.pbl_table. If subsequent calls to rdma_alloc_tid() or rdma_register_tid() fail and the error path frees the mr structure, the PBL table memory is not released via qedr_free_pbl(), leaving it orphaned in kernel memory. Exploitation requires local, low-privileged access and low attack complexity, with no user interaction needed (Feedly).

The primary impact is on system availability. A local attacker with low privileges could repeatedly trigger the error path in __qedr_alloc_mr() to accumulate unreleased kernel memory, leading to resource exhaustion, system performance degradation, and potential denial of service. There is no confidentiality or integrity impact associated with this vulnerability (Feedly).

There is no public proof-of-concept exploit and no evidence of in-the-wild exploitation at this time. The EPSS score is approximately 0.018%, indicating a very low probability of exploitation in the near term. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog (Feedly).

Patches are available for all affected kernel branches. Users should upgrade to Linux kernel versions 5.10.137 or later, 5.15.61 or later, 5.18.18 or later, or 5.19.2 or later, depending on their branch. The fix adds a call to qedr_free_pbl() in the error handling path of __qedr_alloc_mr() to properly release mr->info.pbl_table. For systems that cannot be patched immediately, limiting local user access and monitoring kernel memory usage for unexpected growth are recommended interim measures. Kernel live patching solutions may also be applicable where supported (Feedly, Kernel Patches).

SUSE issued a security advisory (SUSE-2025-02308-1) addressing this and other Linux kernel vulnerabilities, rated as Important (Linux Security). No notable researcher commentary or significant social media discussion has been identified for this vulnerability.