CVE-2026-43055 Linux内核target_core_file未初始化漏洞

/* * Conceptual PoC for CVE-2026-43055 * This code demonstrates the logic flaw leading to the vulnerability. * It simulates the kernel behavior where uninitialized memory causes a check failure. */ #include <stdio.h> #include <stdlib.h> #define MAX_WRITE_STREAMS 10 struct iocb { int ki_write_stream; }; struct aio_cmd { struct iocb iocb; }; // Simulating the vulnerable allocation logic (not zeroing memory) struct aio_cmd* vulnerable_alloc() { // In real kernel: kmalloc instead of kzalloc_flex return (struct aio_cmd*)malloc(sizeof(struct aio_cmd)); } // Simulating the fixed allocation logic struct aio_cmd* fixed_alloc() { struct aio_cmd* cmd = (struct aio_cmd*)malloc(sizeof(struct aio_cmd)); if (cmd) { cmd->iocb.ki_write_stream = 0; // Explicit initialization } return cmd; } int execute_write(struct aio_cmd* cmd) { // Block layer check if (cmd->iocb.ki_write_stream > MAX_WRITE_STREAMS) { printf("[!] Write Failed: Invalid stream ID %d\n", cmd->iocb.ki_write_stream); return -1; } printf("[+] Write Success\n"); return 0; } int main() { printf("--- Testing Vulnerable Scenario ---\n"); struct aio_cmd* cmd_vuln = vulnerable_alloc(); // Note: ki_write_stream is uninitialized here, might contain garbage > MAX_WRITE_STREAMS execute_write(cmd_vuln); free(cmd_vuln); printf("\n--- Testing Fixed Scenario ---\n"); struct aio_cmd* cmd_fixed = fixed_alloc(); execute_write(cmd_fixed); free(cmd_fixed); return 0; }