CVEvulnerability
CVE-2026-98713
- Status
- Received
- Published
- 2026-10-18
- Last modified
- 2026-10-19
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Description
In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Apply the fine-grained UNDEFs without FEAT_FGT
FGUs don't actually require hardware support, so don't gate fgt trap
config insertion on FGT. This is the only action required to allow FGUs
always, as kvm_calculate_traps() already computes the FGU bits with or
without FEAT_FGT.
This also fixes a spurious WARN when a TLBI OS is run on a guest in vEL1
without FEAT_TLBIOS on non FEAT_FGT hardware. In this configuration the
course-grained HCR_EL2.TTLBOS trap reaches the handler handle_tlbi_el1(),
which expects an EL1 TLBI only from vEL2. With FGUs enabled the UNDEF
will be injected without needing the specific handler.
[oliver: Take Wei-Lin's suggested changelog]
References
- https://git.kernel.org/stable/c/1113374a17d7f7d16b02ee0bbd9b1e7a60cbb087 git.kernel.org
- https://git.kernel.org/stable/c/2f4a15c52a552c5244ec27f4ca8bda855594f918 git.kernel.org
- https://git.kernel.org/stable/c/4bdd2b3a708c1feb701cb8b62feb8ad2fd77bb07 git.kernel.org
- https://git.kernel.org/stable/c/af3300b3a6bace925a496f3520e171c07b999c72 git.kernel.org