CVE-2025-68168: jfs: fix uninitialized waitqueue in transaction manager

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-12-16 · updated 2026-10-14

Description

In the Linux kernel, the following vulnerability has been resolved: jfs: fix uninitialized waitqueue in transaction manager The transaction manager initialization in txInit() was not properly initializing TxBlock[0].waitor waitqueue, causing a crash when txEnd(0) is called on read-only filesystems. When a filesystem is mounted read-only, txBegin() returns tid=0 to indicate no transaction. However, txEnd(0) still gets called and tries to access TxBlock[0].waitor via tid_to_tblock(0), but this waitqueue was never initialized because the initialization loop started at index 1 instead of 0. This causes a 'non-static key' lockdep warning and system crash: INFO: trying to register non-static key in txEnd Fix by ensuring all transaction blocks including TxBlock[0] have their waitqueues properly initialized during txInit().

Affected products

Linux kernel: from 5.4.255 before 5.4.302; from 5.10.192 before 5.10.247; from 5.15.123 before 5.15.197; from 6.1.42 before 6.1.159; from 4.14.324 before 4.15; from 4.19.293 before 4.20 — fixed in 4.15, 4.20, 5.10.247, 5.15.197, 5.4.302, 6.1.159

How to fix

Upgrade to a fixed version: Linux kernel 4.15, 4.20, 5.10.247, 5.15.197. Check the vendor advisory for mitigations.

References

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