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CVE-2025-39927

ceph: fix race condition validating r_parent before applying state PUBLISHED

Description (CNA)

In the Linux kernel, the following vulnerability has been resolved: ceph: fix race condition validating r_parent before applying state Add validation to ensure the cached parent directory inode matches the directory info in MDS replies. This prevents client-side race conditions where concurrent operations (e.g. rename) cause r_parent to become stale between request initiation and reply processing, which could lead to applying state changes to incorrect directory inodes. [ idryomov: folded a kerneldoc fixup and a follow-up fix from Alex to move CEPH_CAP_PIN reference when r_parent is updated: When the parent directory lock is not held, req->r_parent can become stale and is updated to point to the correct inode. However, the associated CEPH_CAP_PIN reference was not being adjusted. The CEPH_CAP_PIN is a reference on an inode that is tracked for accounting purposes. Moving this pin is important to keep the accounting balanced. When the pin was not moved from the old parent to the new one, it created two problems: The reference on the old, stale parent was never released, causing a reference leak. A reference for the new parent was never acquired, creating the risk of a reference underflow later in ceph_mdsc_release_request(). This patch corrects the logic by releasing the pin from the old parent and acquiring it for the new parent when r_parent is switched. This ensures reference accounting stays balanced. ]

Affected (CNA)

Vendor / productVersions
Linux / Linuxaffected 9030aaf9bf0a1eee47a154c316c789e959638b0f before dc5aad078abc416dd3d555c50f5308c16ba918a7; affected 9030aaf9bf0a1eee47a154c316c789e959638b0f before db378e6f83ec705c6091c65d482d555edc2b0a72; affected 9030aaf9bf0a1eee47a154c316c789e959638b0f before 2bfe45987eb346e299d9f763f9cd05f77011519f; affected 9030aaf9bf0a1eee47a154c316c789e959638b0f before 15f519e9f883b316d86e2bb6b767a023aafd9d83
Linux / Linuxaffected 2.6.34; unaffected 0 before 2.6.34; unaffected 6.6.160 through 6.6.*; unaffected 6.12.48 through 6.12.*; unaffected 6.16.8 through 6.16.*; unaffected 6.17 through *

CWE

No CWE identifiers supplied.

References

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.