CVE-2026-43336 Linux内核信息泄露漏洞

/* * Conceptual PoC for CVE-2026-43336 * This code demonstrates the nature of the vulnerability: sensitive data * remaining in stack memory after the cryptographic operation. * * Exploitation requires a separate memory read primitive. */ #include <stdio.h> #include <string.h> #include <stdlib.h> #define STATE_SIZE 16 // Mocking the vulnerable function logic void vulnerable_chacha_permutation(unsigned int *state, unsigned int *out_state) { unsigned int permuted_state[STATE_SIZE]; // 1. Copy state to local stack variable memcpy(permuted_state, state, STATE_SIZE * sizeof(unsigned int)); // 2. Perform ChaCha permutation (Invertible operation) // In a real scenario, this is the complex quarter-round logic for (int i = 0; i < STATE_SIZE; i++) { permuted_state[i] = permuted_state[i] ^ 0xDEADBEEF; // Simulated permutation } // 3. Output result memcpy(out_state, permuted_state, STATE_SIZE * sizeof(unsigned int)); // VULNERABILITY: 'permuted_state' is NOT zeroized here. // The data (key material) remains on the stack until overwritten. } // Simulating an attacker reading stack memory after the function returns void simulate_stack_leak() { unsigned int fake_key[STATE_SIZE]; // Initialize with some 'secret' data for(int i=0; i<STATE_SIZE; i++) fake_key[i] = 0xAAAAAAAA + i; unsigned int output[STATE_SIZE]; printf("[*] Calling vulnerable function...\n"); vulnerable_chacha_permutation(fake_key, output); // In a real exploit, the attacker would scan the stack address space // looking for the pattern of 'permuted_state'. printf("[!] Vulnerability: 'permuted_state' may still reside in stack memory.\n"); printf("[!] If an attacker reads this stack frame, they can reverse the permutation.\n"); } int main() { simulate_stack_leak(); return 0; }