CVE-2026-43063 Linux内核XFS释放后重用漏洞

/* * 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; }