CVE-2026-98638

Name	CVE-2026-98638
Description	In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Validate the SVE vector length in pkvm_vcpu_init_sve() pkvm_vcpu_init_sve() clamps only the upper bound of the host-provided sve_max_vl, so an invalid vector length reaches sve_state_size_from_vl() and the WARN_ON() there, which is fatal at EL2. The existing !sve_state_size test rejects such a length, but only after the macro has run. Check sve_vl_valid() before deriving the state size. A valid length cannot yield a zero size, so the !sve_state_size test goes with it.
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)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	bookworm	6.1.176-1	fixed
	bookworm (security)	6.1.190-1	fixed
	trixie	6.12.107-1	fixed
	trixie (security)	6.12.115-2	fixed
	forky	7.2.15-1	fixed
	sid	7.3.3-1	fixed

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

Package	Type	Release	Fixed Version
linux	source	bookworm	(not affected)
linux	source	trixie	(not affected)
linux	source	(unstable)	7.2.9-1

Notes

[trixie] - linux <not-affected> (Vulnerable code not present)
[bookworm] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/2a2eb10795a1e495aebc7f829ccecb72c05b4fd9 (7.3-rc5)