CVE-2025-37896
📋 TL;DR
A divide-by-zero vulnerability in the Linux kernel's SPI memory subsystem can cause kernel panics when handling certain SPI flash memory operations with zero dummy bytes. This affects systems using SPI flash memory devices like Winbond SPINAND flash. The vulnerability leads to denial of service but does not allow arbitrary code execution.
💻 Affected Systems
- Linux kernel
📦 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 →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, requiring physical or remote reboot.
Likely Case
System crash when specific SPI flash operations are performed, causing temporary unavailability.
If Mitigated
No impact if patched or if affected SPI operations are not used.
🎯 Exploit Status
Exploitation requires access to SPI flash subsystem, typically through hardware interaction or privileged software.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits 1915dbd67dadc0bb35670c8e28229baa29368d17 and 8e4d3d8a5e51e07bd0d6cdd81b5e4af79f796927
Vendor Advisory: https://git.kernel.org/stable/c/1915dbd67dadc0bb35670c8e28229baa29368d17
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix. 2. Check with your distribution for security updates. 3. Reboot system after kernel update.
🔧 Temporary Workarounds
Avoid affected SPI flash operations
linuxPrevent use of SPI flash operations with zero dummy bytes if possible.
🧯 If You Can't Patch
- Restrict access to SPI flash hardware interfaces.
- Monitor system logs for kernel panic events related to SPI operations.
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if SPI flash devices are in use. Look for kernel panic logs mentioning spi_mem_calc_op_duration.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes the fix commits or is newer than patched versions.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages with 'divide error' in spi_mem_calc_op_duration function
- System crash logs related to SPI operations
SIEM Query:
event_type:kernel_panic AND message:"spi_mem_calc_op_duration"