ksmbd: detach blocked lock requests before freeing
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
- —
- Confidentiality · integrity · availability
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- Fix status
- Fixed
No CVSS vector from any source. Fix status from CNA.
Summary
In the Linux kernel, the following vulnerability has been resolved: ksmbd: detach blocked lock requests before freeing A file_lock retained by ksmbd for byte-range lock bookkeeping can still be part of the VFS blocked-request graph. In particular, the VFS can chain a new waiter below an already blocked request through flc_blocked_requests. The ksmbd_file reference count does not cover that graph. Both __ksmbd_close_fd() and the cross-request unlock path free these retained file_lock objects directly. If a dependent waiter is still attached, locks_release_private() hits BUG_ON(!list_empty(&flc->flc_blocked_requests)). The same lifetime mismatch can leave a freed ksmbd_lock reachable through its request-local llist. Detach the file_lock from the blocked-request graph before freeing it in the close, cross-request unlock, and rollback paths. locks_delete_block() also wakes requests chained below the object. Remove llist when a completed lock is published so a globally visible ksmbd_lock no longer points into the submitting worker's stack.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.1.191, 6.6.160, 6.12.114, 6.18.57, 7.2.6, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 7 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-10-02 Threatist record created from CVE-2026-90155
- 2026-10-03 Alias added: GHSA-52g3-8w7f-v5w2
- 2026-10-13 Affected versions changed · Red Hat
- 2026-10-13 CVSS score added · Red Hat
- 2026-10-16 Fix available: Linux/[email protected], Linux/Linux@f77d2accafca529e0ea3f979eb6e6cf1dac05c90 · CNA
- 2026-10-16 1 new reference · CNA
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-21 Fix available: Linux/[email protected], Linux/[email protected], Linux/Linux@d20d3f6ad8b0b6f4e1bb32cdf7eca251962e8f04 +1 · CNA
- 2026-10-21 2 new references · CNA
- 2026-10-30 Fix available: Linux/Linux@4e8b69c06bd6583ec11abef4fae50c2c8d5f3679, Linux/[email protected] · CNA
- 2026-10-30 1 new reference · CNA
- 2026-11-06 Affected versions changed · Red Hat
References
Other 6
- https://git.kernel.org/stable/c/4e8b69c06bd6583ec11abef4fae50c2c8d5f3679
- https://git.kernel.org/stable/c/d20d3f6ad8b0b6f4e1bb32cdf7eca251962e8f04
- https://git.kernel.org/stable/c/d31db79cfaa9fce6649772ad279779473ba8aef9
- https://git.kernel.org/stable/c/f77d2accafca529e0ea3f979eb6e6cf1dac05c90
- https://git.kernel.org/stable/c/514a0b2bc949963497e66cacd433f65dc768a71d
- https://git.kernel.org/stable/c/215e8816b1ac25176d911abb8704390413ccee4b
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Sources
- CVE-2026-90155 · CVE Program
- CVE-2026-90155 · NVD
- FIRST EPSS
- GHSA-52g3-8w7f-v5w2 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-90155 · Red Hat security data · CC BY 4.0
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