CVE-2025-39842: ocfs2: prevent release journal inode after journal shutdown

Severity: medium (CVSS 5.5 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: 2025-09-19 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: ocfs2: prevent release journal inode after journal shutdown Before calling ocfs2_delete_osb(), ocfs2_journal_shutdown() has already been executed in ocfs2_dismount_volume(), so osb->journal must be NULL. Therefore, the following calltrace will inevitably fail when it reaches jbd2_journal_release_jbd_inode(). ocfs2_dismount_volume()-> ocfs2_delete_osb()-> ocfs2_free_slot_info()-> __ocfs2_free_slot_info()-> evict()-> ocfs2_evict_inode()-> ocfs2_clear_inode()-> jbd2_journal_release_jbd_inode(osb->journal->j_journal, Adding osb->journal checks will prevent null-ptr-deref during the above execution path.

Affected products

Debian Linux: 11.0
Linux kernel: from 5.16 before 6.1.151; from 6.2 before 6.6.105; from 6.7 before 6.12.46; from 6.13 before 6.16.6; 6.17-rc1, 6.17-rc2, 6.17-rc3, 6.17-rc4 — fixed in 6.1.151, 6.12.46, 6.16.6, 6.6.105

How to fix

Upgrade to a fixed version: Linux kernel 6.1.151, 6.12.46, 6.16.6, 6.6.105. Check the vendor advisory for mitigations.

References

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