CVE-2023-53651 Linux内核exc3000驱动定时器未停止导致UAF漏洞

/* * CVE-2023-53651 - Linux Kernel exc3000 UAF via timer not stopped on shutdown * * This PoC demonstrates the vulnerability by simulating the race condition * between driver unbind and timer firing. * * Note: This is a conceptual PoC. Actual exploitation requires kernel module * loading privileges and a real or emulated exc3000 touchscreen device. */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/timer.h> #include <linux/input.h> #include <linux/slab.h> /* Simulated exc3000 private data structure */ struct exc3000_data { struct input_dev *input; struct timer_list timer; char data_buffer[64]; int state; }; static struct exc3000_data *exc_data; /* Timer callback - simulates the vulnerable timer handler */ static void exc3000_timer_handler(struct timer_list *t) { struct exc3000_data *data = from_timer(data, t, timer); /* VULNERABILITY: data may have been freed if timer was not stopped */ pr_info("Timer fired, accessing data->state: %d\n", data->state); pr_info("Timer fired, data buffer: %s\n", data->data_buffer); /* Re-arm timer */ mod_timer(&data->timer, jiffies + msecs_to_jiffies(100)); } /* Simulated probe function - registers and starts timer */ static int __init exc3000_vuln_init(void) { exc_data = kzalloc(sizeof(struct exc3000_data), GFP_KERNEL); if (!exc_data) return -ENOMEM; /* Setup and start timer */ timer_setup(&exc_data->timer, exc3000_timer_handler, 0); mod_timer(&exc_data->timer, jiffies + msecs_to_jiffies(100)); pr_info("exc3000: Timer started, data allocated at %p\n", exc_data); return 0; } /* Simulated remove function - VULNERABLE: does NOT stop timer */ static void __exit exc3000_vuln_exit(void) { /* VULNERABILITY: Missing timer_shutdown_sync(&exc_data->timer) */ /* This causes UAF when timer fires after kfree */ pr_info("exc3000: Freeing data without stopping timer at %p\n", exc_data); kfree(exc_data); exc_data = NULL; /* Timer still active - will fire and access freed memory -> UAF/Oops */ } module_init(exc3000_vuln_init); module_exit(exc3000_vuln_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Security Research"); MODULE_DESCRIPTION("CVE-2023-53651 PoC - exc3000 timer UAF"); /* * Trigger steps: * 1. Load the vulnerable module: insmod exc3000_vuln.ko * 2. Wait for timer to be active * 3. Unload the module: rmmod exc3000_vuln * 4. Timer fires after kfree -> Use-After-Free -> kernel Oops/panic * * Fix: Add timer_shutdown_sync(&exc_data->timer) before kfree() in exit path. */