CVE-2025-38648
📋 TL;DR
A NULL pointer dereference vulnerability in the STM32 SPI driver of the Linux kernel could cause a kernel panic or system crash when accessing uninitialized configuration data. This affects systems using STM32-based SPI hardware with vulnerable kernel versions. The vulnerability requires local access to trigger.
💻 Affected Systems
- Linux kernel with STM32 SPI driver
📦 What is this software?
Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash and denial of service, potentially requiring physical reboot.
Likely Case
System crash or instability when initializing SPI devices on affected STM32 hardware.
If Mitigated
Minor system instability during driver initialization, likely caught during boot or device probing.
🎯 Exploit Status
Exploitation requires local access and ability to trigger SPI device initialization. Not trivial but possible for local users.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patched in stable kernel versions via provided git commits
Vendor Advisory: https://git.kernel.org/stable/c/21f1c800f6620e43f31dfd76709dbac8ebaa5a16
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version containing the fix. 2. Reboot system to load new kernel. 3. Verify driver loads without errors.
🔧 Temporary Workarounds
Disable STM32 SPI driver
LinuxPrevent loading of vulnerable driver module
echo 'blacklist spi-stm32' >> /etc/modprobe.d/blacklist.conf
rmmod spi-stm32
🧯 If You Can't Patch
- Restrict local user access to prevent malicious triggering of SPI initialization
- Monitor system logs for kernel panic events related to SPI driver
🔍 How to Verify
Check if Vulnerable:
Check if STM32 SPI driver is loaded: lsmod | grep spi-stm32 and check kernel version against patched releasesCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes patch commit: uname -r and check for patch in changelog📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- NULL pointer dereference errors in dmesg
- SPI driver initialization failures
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("NULL pointer dereference" OR "kernel panic" OR "spi-stm32")🔗 References
- https://git.kernel.org/stable/c/21f1c800f6620e43f31dfd76709dbac8ebaa5a16
- https://git.kernel.org/stable/c/3a571a8d52272cc26858ab1bc83d0f66e5dee938
- https://git.kernel.org/stable/c/6031a54f4eac921efe6122a561d44df89b37f2d4
- https://git.kernel.org/stable/c/a7645815edf4478f3258bb0db95a08986a77f5c0
- https://git.kernel.org/stable/c/cc063d23ad80ef7d201c41b2716b1bae7c662cf9
