| Kura | RT-Thread 5.1.0 Insufficient Control Flow Management |
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| Gaskiya | # Control Flow Hijacking Vulnerability in sys_device_read Syscall in RT-Thread
## Summary
I have identified a critical vulnerability in the `sys_device_read` system call in RT-Thread. This vulnerability stems from insufficient pointer validation and could allow an attacker to achieve arbitrary code execution through control flow hijacking. The issue is particularly severe as it could be exploited by a compromised user thread to gain elevated privileges.
## Vulnerable Code Location
The vulnerability is present in the following files:
1. `components/drivers/core/device.c`: Contains the vulnerable macro definition and implementation
2. `components/lwp/lwp_syscall.c`: Contains the system call implementation
## Vulnerability Description
The vulnerability exists in the `device_read` macro and its usage:
```c
#define device_read (dev->ops ? dev->ops->read : RT_NULL)
```
In `lwp_syscall.c`:
```c
rt_ssize_t sys_device_read(rt_device_t dev, rt_off_t pos, void *buffer, rt_size_t size)
{
return rt_device_read(dev, pos, buffer, size);
}
```
In `rt_device_read`:
```c
rt_ssize_t rt_device_read(rt_device_t dev,
rt_off_t pos,
void *buffer,
rt_size_t size)
{
/* parameter check */
RT_ASSERT(dev != RT_NULL);
RT_ASSERT(rt_object_get_type(&dev->parent) == RT_Object_Class_Device);
if (dev->ref_count == 0)
{
rt_set_errno(-RT_ERROR);
return 0;
}
/* call device_read interface */
if (device_read != RT_NULL)
{
return device_read(dev, pos, buffer, size); //Vulnerability here
}
/* set error code */
rt_set_errno(-RT_ENOSYS);
return 0;
}
```
The code only performs a NULL check on the function pointer but fails to verify whether the pointer points to valid memory or a valid function. This oversight can lead to control flow hijacking when the function pointer is called.
## Impact
This vulnerability has severe security implications:
1. **Arbitrary Code Execution**: An attacker could potentially corrupt the `dev->ops->read` function pointer to point to arbitrary memory locations, leading to arbitrary code execution.
2. **Privilege Escalation**: Since this vulnerability exists in the kernel space, successful exploitation could lead to privilege escalation.
3. **System Compromise**: The ability to execute arbitrary code in kernel space could lead to complete system compromise, including:
- Bypassing security mechanisms
- Accessing sensitive data
- Installing persistent malware
- Disabling security features
## Mitigation
1. Implement proper validation of function pointers before calling them
2. Add additional checks to verify the integrity of the device structure
3. Consider implementing Control Flow Integrity (CFI) mechanisms
4. Add bounds checking for pointer dereferencing
## References
1. RT-Thread source code: `components/drivers/core/device.c`
2. RT-Thread source code: `components/lwp/lwp_syscall.c`
3. https://github.com/RT-Thread/rt-thread |
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| Màdùmga | Zephyr Saxon (UID 80853) |
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| Furta | 06/12/2025 05:55 (8 Wurɗi 전) |
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| Gargajiya | 06/26/2025 09:11 (14 days later) |
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| Halitta | Dublikat |
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| VulDB gite | 313959 [RT-Thread har 5.1.0 device.c Pufferüberlauf] |
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| Nganji | 0 |
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