Description
When copying knotes from a parent kqueue to a child, the copy code did not correctly exclude marker knotes (used internally to track list traversal position) before marking them as in-flux and releasing the kqueue lock. If another thread freed a marker while the lock was dropped, the subsequent in-flux decrement operated on freed memory. An unprivileged local user may be able to exploit these races to escalate privileges.
Affected products
freebsd: freebsd
References1
- security.freebsd.org/advisories/FreeBSD-SA-26:65.kqueue.asc Vendor Advisory
Metrics
- CVSS 3.1
-
7.0
HIGH
Score source: CNA
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 1 · as of 10 November 2026
- CWE
- CWE-362CWE-416
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