CVE-2026-98115: ksmbd: safely drain sessions during logoff

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-25 · updated 2026-10-19
Weakness: CWE-362

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: safely drain sessions during logoff SMB3 multichannel allows requests for one session to run on multiple connections. Wait for all channels bound to a session before freeing shared session objects. A deferred byte-range lock remains counted as a running request and only wakes when its file closes. Wake blocked locks during the drain without unpublishing or modifying their file objects. Synchronous CANCEL requests must invoke their cancellation callback to wake pending operations, while CHANGE_NOTIFY completion remains specific to the asynchronous path. Serialize session teardown with channel registration and previous-session cleanup, and use atomic work-state transitions so LOGOFF, CANCEL, and connection teardown invoke cancellation callbacks only once.

Affected products

Linux kernel: from 6.6.48 before 6.7; from 6.10.7 before 6.11; from 6.11.1 before 7.2.7; 6.11, 6.11-rc5, 6.11-rc6, 6.11-rc7, 7.3-rc1 — fixed in 6.11, 6.7, 7.2.7

How to fix

Upgrade to a fixed version: Linux kernel 6.11, 6.7, 7.2.7. Check the vendor advisory for mitigations.

References

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