CVE-2026-43063

/* * PoC Concept for CVE-2026-43063 * This demonstrates the logic flaw where irele is called on a failed iget. * Triggering this requires a crafted XFS filesystem image that forces * xlog_recovery_iget to fail during recovery. */ #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> // Mocking the kernel structure logic for demonstration struct inode { int i_count; }; int xlog_recovery_iget_fail(struct inode **ipp) { // Simulate failure: do not set *ipp to NULL return -1; // Return error } void irele(struct inode *ip) { if (ip) { ip->i_count--; printf("Releasing inode\n"); } else { printf("Inode is NULL, safe to release\n"); } } void vulnerable_function() { struct inode *ip; // ip is uninitialized (dangling pointer) // Step 1: Attempt to get inode, which fails if (xlog_recovery_iget_fail(&ip)) { printf("iget failed, but ip was not NULL-ed.\n"); // Vulnerability: Original code did not check error or NULL ip before irele // irele(ip); // This would cause the crash in the kernel } // Exploit trigger path would look like this in the kernel: // irele(ip); } int main() { printf("Simulating CVE-2026-43063 trigger logic...\n"); vulnerable_function(); return 0; }

{"cve": {"id": "CVE-2026-43063", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-05T16:16:15.467", "lastModified": "2026-05-08T13:16:37.457", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfs: don't irele after failing to iget in xfs_attri_recover_work\n\nxlog_recovery_iget* never set @ip to a valid pointer if they return\nan error, so this irele will walk off a dangling pointer. Fix that."}], "metrics": {"cvssMetricV31": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "references": [{"url": "https://git.kernel.org/stable/c/40082d08b638485cbaa543dc8087a3d1844d6f08", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/70685c291ef82269180758130394ecdc4496b52c", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/a1a5df1038f0b3c560d204270373621a4e622808", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b5c5a50c2f513d4a13a6763564a07b470e69cc5a", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}]}}