CVE-2026-64284

Name	CVE-2026-64284
Description	In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Ensure vendor's exit handler runs before fastpath userspace exits Move the handling of fastpath userspace exits into vendor code to ensure KVM runs vendor specific operations that need to run before userspace gains control of the vCPU. E.g. for VMX (and soon to be for SVM as well), KVM needs to flush the PML buffer prior to exiting to userspace, otherwise any memory written by the final KVM_RUN might never be flagged as dirty. Note, waiting to snapshot CR0 and CR3 until svm_handle_exit() is flawed in general, as that risks consuming stale state in a fastpath handler. That will be addressed in a future change.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DLA-4724-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	bullseye	5.10.223-1	fixed
	bullseye (security)	5.10.262-1	fixed
	bookworm	6.1.176-1	fixed
	bookworm (security)	6.1.180-1	fixed
	trixie	6.12.94-1	vulnerable
	trixie (security)	6.12.101-1	fixed
	forky	7.1.7-1	fixed
	sid	7.1.8-1	fixed
linux-6.12 (PTS)	bookworm (security)	6.12.100-1~deb12u1	fixed

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

Package	Type	Release	Fixed Version	Origin
linux	source	bullseye	(not affected)
linux	source	bookworm	(not affected)
linux	source	trixie	6.12.96-1
linux	source	(unstable)	7.1.4-1
linux-6.12	source	bookworm	6.12.100-1~deb12u1	DLA-4724-1

Notes

[bookworm] - linux <not-affected> (Vulnerable code not present)
[bullseye] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/0ffedf43910e44b76c2c1db4e9fbf12b268190c1 (7.2-rc1)