CVE-2024-56571 in Linux
摘要
由 VulDB • 2026-06-16
Based on the kernel log snippet provided, here is an analysis of the crash and potential causes.
### **Summary** The system experienced a **kernel panic/oops** in the **USB Video Class (UVC)** driver (`uvcvideo`) during device probing. The crash occurred in `media_create_pad_link`, which is part of the V4L2 (Video for Linux 2) media controller subsystem.
### **Key Details from the Log** 1. **Crash Location**: * `media_create_pad_link+0x2c4/0x2e0` * Called from `uvc_mc_register_entities` → `uvc_register_chains` → `uvc_probe`. * This indicates the crash happens when the UVC driver tries to set up media links between entities (e.g., between the USB interface and the video node).
2. **Exception Type**: * `exc_invalid_op` / `asm_exc_invalid_op`: This usually means an **invalid opcode** was executed. In the context of kernel oops, this often points to: * Corrupted function pointers. * Memory corruption (use-after-free, buffer overflow). * A bug in the kernel code itself (e.g., calling a function with wrong arguments or in an invalid state).
3. **Call Trace**: ``` ? media_create_pad_link+0x2c4/0x2e0 ? __v4l2_device_register_subdev+0x202/0x210 uvc_mc_register_entities+0x358/0x400 uvc_register_chains+0x1fd/0x290 uvc_probe+0x380e/0x3dc0 ``` The driver is trying to register sub-devices and create media links for a USB webcam or similar device.
4. **Registers**: * `CR2: 0000592cc27635b0`: This is the faulting address if it were a page fault. However, since it's an `invalid_op`, this might not be directly relevant, but it shows the CPU state at the time of the crash. * `R11: 0001888004313290`: Likely a pointer or argument passed to the function.
### **Possible Causes** 1. **Kernel Bug in UVC/Media Controller**: * There may be a bug in the `media_create_pad_link` function or how the UVC driver calls it. This could be triggered by a specific USB device descriptor or configuration. * Check if your kernel version is up-to-date. This might be a known bug fixed in newer kernels.
2. **Hardware/Device-Specific Issue**: * The crash might be triggered by a specific USB webcam or device with non-standard descriptors. Try unplugging other USB devices to isolate the culprit. * If you recently plugged in a new USB camera, try using a different one or a different USB port.
3. **Memory Corruption**: * If the system has been running for a long time or under heavy load, memory corruption could cause invalid function calls. Rebooting the system might temporarily resolve it.
4. **Driver Conflict**: * Another driver might be interfering with the UVC driver. Check `dmesg` for other errors around the same time.
### **Troubleshooting Steps** 1. **Update Kernel**: * Ensure you are running the latest stable kernel for your distribution. Bugs in `uvcvideo` and `media` subsystems are occasionally fixed in newer versions.
2. **Identify the Device**: * Run `lsusb` before and after plugging in the device to identify which USB device is causing the issue. * Check `dmesg` for the USB device enumeration messages just before the crash.
3. **Test with a Different Device**: * Try using a different USB webcam or device to see if the crash persists. If it only happens with one device, it’s likely a device-specific bug or descriptor issue.
4. **Check for Known Bugs**: * Search for the bug report using keywords like `uvcvideo media_create_pad_link invalid_op` or `uvc_mc_register_entities crash` on your distribution’s bug tracker or Linux kernel mailing lists.
5. **Disable Media Controller (Workaround)**: * If you don’t need advanced media controller features, you might try disabling the media controller for the UVC driver. This can
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