Critical PTM Cycle Trigger Logic Vulnerability in Linux Kernel
Summary
CVE-2025-37875: In the Linux kernel, the following vulnerability has been resolved: igc: fix PTM cycle trigger logic Writing to clear the PTM status 'valid' bit while the PTM cycle is triggered results in unreliable PTM operation. Affects linux versions < 6.1.135-1. Fixed in 6.1.135-1. How to fix ↓
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Background
The Linux kernel is the core component of many operating systems, providing essential services for hardware and software interaction. It is known for its stability, performance, and security features. However, it is also susceptible to vulnerabilities that can impact system reliability and security. This specific vulnerability affects the igc driver, which is responsible for Intel Ethernet controllers, particularly in handling Precision Time Protocol (PTP) transactions.
Vulnerability Detail
In the Linux kernel, a vulnerability has been identified in the igc driver related to the Precision Time Measurement (PTM) cycle trigger logic. Writing to clear the PTM status 'valid' bit while the PTM cycle is triggered can lead to unreliable PTM operations. This issue can cause the PHC2SYS tool to fail with a timeout error, disrupting time synchronization processes. Additionally, it can lead to a hang in the igc_probe() function when loading the igc driver in a kdump kernel, potentially breaking the kdump process during system crashes.
How To Fix
Minimum fixed version
6.1.135-1
This is the first release that contains the fix.
sudo apt-get install --only-upgrade linuxTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, avoid triggering PTM cycles while the system is under heavy load or during critical operations. Additionally, you can reproduce the issue using the following command, but be cautious as it may lead to system instability:
$ sudo phc2sys -R 1000 -O 0 -i tsn0 -m
Conclusion
The vulnerability in the igc driver of the Linux kernel poses significant risks to system stability and reliability, particularly in environments relying on precise time synchronization. It is crucial to apply the recommended updates to mitigate these risks effectively.
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FAQ
The vulnerability can lead to unreliable PTM operations and may cause system hangs during driver probing, affecting system stability.
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Precision Time Measurement (PTM) is crucial for time-sensitive applications, ensuring accurate synchronization across networked systems.
If an immediate update is not possible, consider implementing the suggested workaround to minimize the risk of encountering the vulnerability.
Detailed information about this vulnerability can be found in the official CVE database or through the Linux kernel mailing lists.
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