CVE-2026-31395: Linux内核bnxt_en驱动越界访问漏洞

/* * PoC Concept for CVE-2026-31395 * This code simulates the vulnerable logic in the kernel driver. * In a real scenario, the 'type' value comes from a malicious NIC. */ #include <stdio.h> #include <stdint.h> #define BNXT_TRACE_MAX 13 // 0x0 to 0xc (Fixed size) // Simulating the structure in kernel memory struct bnxt_bs_trace { uint32_t magic_byte; uint32_t last_offset; uint32_t wrapped; }; // Simulated vulnerable function logic void vulnerable_handler(uint16_t type, struct bnxt_bs_trace *bp_bs_trace) { printf("[VULNERABLE] Received event with type: %d\n", type); // VULNERABILITY: No bounds check on 'type' before using it as an index // If type is 0xFFFF, this accesses memory way outside the array bounds struct bnxt_bs_trace *bs_trace = &bp_bs_trace[type]; // This leads to out-of-bounds write/corruption bs_trace->last_offset = 0xDEADBEEF; bs_trace->wrapped = 1; printf("[CRASH] Writing to address %p (Out of Bounds!)\n", bs_trace); } int main() { // Allocate a small buffer to simulate bp->bs_trace[] struct bnxt_bs_trace *trace_buffer = (struct bnxt_bs_trace*)malloc(sizeof(struct bnxt_bs_trace) * BNXT_TRACE_MAX); // Simulate a malicious NIC sending a large 'type' value (e.g., 65535) uint16_t malicious_type = 65535; // Trigger the vulnerability vulnerable_handler(malicious_type, trace_buffer); free(trace_buffer); return 0; }