CVE-2026-31436

/* * Conceptual Proof of Concept for CVE-2026-31436 * This snippet demonstrates the logic error in llist_abort_desc(). * Triggering this requires access to the IDXD device interface. */ #include <linux/module.h> #include <linux/kernel.h> // Mock structures to represent the kernel code context struct desc { struct list_head node; int status; }; void complete_desc(struct desc *d) { // Function to complete a descriptor if (!d) { printk(KERN_ALERT "Triggering NULL pointer dereference!\n"); // panic("PoC Trigger"); } } // Vulnerable function logic reconstruction void llist_abort_desc_vulnerable(struct list_head *flist, struct desc *found) { struct desc *d, *tmp; // Simulate list traversal list_for_each_entry_safe(d, tmp, flist, node) { // ... logic processing ... /* * VULNERABILITY: The code completes 'found' instead of 'd'. * If 'found' is NULL (common in some error paths), this crashes the kernel. */ complete_desc(found); // Bug: Should be complete_desc(d); } } // Module initialization (for demonstration) int init_module(void) { printk(KERN_INFO "CVE-2026-31436 PoC Loaded\n"); return 0; } void cleanup_module(void) { printk(KERN_INFO "CVE-2026-31436 PoC Unloaded\n"); } MODULE_LICENSE("GPL");

{"cve": {"id": "CVE-2026-31436", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-22T14:16:36.843", "lastModified": "2026-05-19T22:10:37.267", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndmaengine: idxd: fix possible wrong descriptor completion in llist_abort_desc()\n\nAt the end of this function, d is the traversal cursor of flist, but the\ncode completes found instead. This can lead to issues such as NULL pointer\ndereferences, double completion, or descriptor leaks.\n\nFix this by completing d instead of found in the final\nlist_for_each_entry_safe() loop."}], "metrics": {"cvssMetricV31": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "6.12.80", "matchCriteriaId": "F1E59CA7-28C1-4587-BC4E-7056631D9864"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.21", "matchCriteriaId": "ED39847A-3B46-4729-B7CA-B2C30B9FA8FE"}, {"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"}, {"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/0e4f43779d550e559be13a5cdb763bad92c4cc99", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/82656e8daf8de00935ae91b91bed43f4d6e0d644", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/e1c9866173c5f8521f2d0768547a01508cb9ff27", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/e21da2ad8844585040fe4b82be1ad2fe99d40074", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}