CVE-2026-80920

NameCVE-2026-80920
DescriptionIn the Linux kernel, the following vulnerability has been resolved: io_uring: defer eventfd signaling when queued from a wakeup handler io_req_local_work_add() signals the CQ ring eventfd inline when it is the one to push the first entry onto ->work_list. For DEFER_TASKRUN rings that add is frequently done from a waitqueue wakeup handler, where an arbitrary waitqueue lock is held. eventfd_signal_mask() only refuses to recurse when current->in_eventfd is set, but that bit is set by eventfd_signal_mask() itself. If the wake chain starts somewhere else, signal goes out inline and can feed back into epoll. Add IOU_F_TWQ_IN_WAKE, set it on the task_work add done from the three waitqueue callbacks, and use it to force io_eventfd_signal() down the existing call_rcu_hurry() deferral instead of signaling inline.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
linux (PTS)bookworm6.1.176-1vulnerable
bookworm (security)6.1.187-1vulnerable
trixie6.12.107-1vulnerable
trixie (security)6.12.111-1vulnerable
forky7.2.6-1fixed
sid7.2.8-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
linuxsource(unstable)7.1.12-1

Notes

https://git.kernel.org/linus/cd305ee3633a45fcf5f3a5d83f99f3cb77d87b6e (7.3-rc1)

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