Junglewise Threat Intelligence

CVE-2025-68168: Linux Kernel JFS denial of service via uninitialized waitqueue

CVE-2025-68168 · Severity: high · CVSS 7.8 · Published 2025-12-16

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A vulnerability in the Linux kernel's JFS filesystem component can cause a system crash. When the filesystem is used in read-only mode, certain internal management tasks are not properly set up, leading to a critical error when the system tries to close a file transaction. This could allow a local user to cause a denial-of-service by crashing the operating system.

Technical details

A flaw exists in the JFS (Journaled File System) transaction manager within the Linux kernel. During initialization in `txInit()`, the waitqueue for the first transaction block (`TxBlock[0]`) is skipped because the initialization loop incorrectly starts at index 1. On read-only filesystems, `txBegin()` returns a transaction ID (tid) of 0; subsequent calls to `txEnd(0)` attempt to access the uninitialized waitqueue in `TxBlock[0]`. This results in a 'non-static key' lockdep warning and a kernel panic (system crash). The issue is resolved by ensuring the initialization loop in `txInit()` starts at index 0.

Affected products

  • Linux Linux Kernel 5.4.255 to 5.4.302, 5.10.192 to 5.10.247, 5.15.123 to 5.15.197, 6.1.42 to 6.1.159

Timeline

  • 2025-12-16: advisory: CVE-2025-68168 published by NVD/kernel.org

References