CVE-2026-23106
Unknown Unknown - Not Provided
Race Condition in Linux Kernel Timekeeping Causes Incorrect Updates

Publication date: 2026-02-04

Last updated on: 2026-03-19

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: timekeeping: Adjust the leap state for the correct auxiliary timekeeper When __do_ajdtimex() was introduced to handle adjtimex for any timekeeper, this reference to tk_core was not updated. When called on an auxiliary timekeeper, the core timekeeper would be updated incorrectly. This gets caught by the lock debugging diagnostics because the timekeepers sequence lock gets written to without holding its associated spinlock: WARNING: include/linux/seqlock.h:226 at __do_adjtimex+0x394/0x3b0, CPU#2: test/125 aux_clock_adj (kernel/time/timekeeping.c:2979) __do_sys_clock_adjtime (kernel/time/posix-timers.c:1161 kernel/time/posix-timers.c:1173) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:131) Update the correct auxiliary timekeeper.
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Meta Information
Published
2026-02-04
Last Modified
2026-03-19
Generated
2026-05-07
AI Q&A
2026-02-04
EPSS Evaluated
2026-05-05
NVD
CVE-2026-23106
EUVD
EUVD-2026-5435
Affected Vendors & Products
Showing 7 associated CPEs
Vendor Product Version / Range
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel From 6.17 (inc) to 6.18.8 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability exists in the Linux kernel's timekeeping subsystem. Specifically, when the function __do_adjtimex() was introduced to handle adjtimex calls for any timekeeper, it failed to update the correct reference for auxiliary timekeepers. Instead, it incorrectly updated the core timekeeper. This caused the timekeepers sequence lock to be written to without holding its associated spinlock, which is a synchronization error detected by lock debugging diagnostics.


How can this vulnerability impact me? :

The vulnerability can lead to incorrect updates in the timekeeping subsystem of the Linux kernel, potentially causing synchronization issues or race conditions. This may result in system instability or unexpected behavior related to time adjustments. Additionally, the lock debugging diagnostics warning indicates a concurrency control problem that could affect system reliability.


How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:

I don't know


How can this vulnerability be detected on my network or system? Can you suggest some commands?

This vulnerability can be detected by monitoring kernel lock debugging diagnostics for warnings related to timekeeper sequence locks being written without holding the associated spinlock.

Specifically, look for kernel warnings similar to: "WARNING: include/linux/seqlock.h:226 at __do_adjtimex+0x394/0x3b0" indicating improper updates to the auxiliary timekeeper.

You can check the kernel logs using commands such as:

  • dmesg | grep -i seqlock
  • journalctl -k | grep -i seqlock
  • journalctl -k | grep -i adjtimex

What immediate steps should I take to mitigate this vulnerability?

The immediate mitigation is to update the Linux kernel to a version where this vulnerability has been fixed.

The fix involves correcting the reference to the auxiliary timekeeper in the __do_ajdtimex() function to ensure proper locking and timekeeper updates.

Until the kernel is updated, monitoring for the described kernel warnings can help detect exploitation attempts.


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