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Description

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. ]

PUBLISHED Reserved 2025-04-16 | Published 2025-10-01 | Updated 2025-10-01 | Assigner Linux

Product status

Default status
unaffected

1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before db378e6f83ec705c6091c65d482d555edc2b0a72
affected

1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 2bfe45987eb346e299d9f763f9cd05f77011519f
affected

1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 15f519e9f883b316d86e2bb6b767a023aafd9d83
affected

Default status
affected

6.12.48
unaffected

6.16.8
unaffected

6.17
unaffected

References

git.kernel.org/...c/db378e6f83ec705c6091c65d482d555edc2b0a72

git.kernel.org/...c/2bfe45987eb346e299d9f763f9cd05f77011519f

git.kernel.org/...c/15f519e9f883b316d86e2bb6b767a023aafd9d83

cve.org (CVE-2025-39927)

nvd.nist.gov (CVE-2025-39927)

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