VulnerabilityPublished 17 Sep 2026Updated 21 Oct 2026

CVE-2026-90155: Linux kernel · ksmbd: detach blocked lock requests before freeing

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in f77d2accafca529e0ea3f979eb6e6cf1dac05c90 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 17:30 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in f77d2accafca529e0ea3f979eb6e6cf1dac05c90, d31db79cfaa9fce6649772ad279779473ba8aef9, d20d3f6ad8b0b6f4e1bb32cdf7eca251962e8f04 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 17 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ d63528eb0d43c4796c42aad56889dec12cf4e122, < f77d2accafca529e0ea3f979eb6e6cf1dac05c90	Fixed in f77d2accafca529e0ea3f979eb6e6cf1dac05c90
LinuxLinux	Affected ≥ d63528eb0d43c4796c42aad56889dec12cf4e122, < d31db79cfaa9fce6649772ad279779473ba8aef9	Fixed in d31db79cfaa9fce6649772ad279779473ba8aef9
LinuxLinux	Affected ≥ d63528eb0d43c4796c42aad56889dec12cf4e122, < d20d3f6ad8b0b6f4e1bb32cdf7eca251962e8f04	Fixed in d20d3f6ad8b0b6f4e1bb32cdf7eca251962e8f04
LinuxLinux	Affected ≥ d63528eb0d43c4796c42aad56889dec12cf4e122, < 514a0b2bc949963497e66cacd433f65dc768a71d	Fixed in 514a0b2bc949963497e66cacd433f65dc768a71d
LinuxLinux	Affected ≥ d63528eb0d43c4796c42aad56889dec12cf4e122, < 215e8816b1ac25176d911abb8704390413ccee4b	Fixed in 215e8816b1ac25176d911abb8704390413ccee4b
LinuxLinux	Affected =5.15	Fixed in–

Description

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.

References

Community reviews

Loading reviews…