CVE-2026-43214

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

KVM: x86: Add SRCU protection for reading PDPTRs in __get_sregs2()

Add SRCU read-side protection when reading PDPTR registers in

__get_sregs2().

Reading PDPTRs may trigger access to guest memory:

kvm_pdptr_read() -> svm_cache_reg() -> load_pdptrs() ->

kvm_vcpu_read_guest_page() -> kvm_vcpu_gfn_to_memslot()

kvm_vcpu_gfn_to_memslot() dereferences memslots via __kvm_memslots(),

which uses srcu_dereference_check() and requires either kvm->srcu or

kvm->slots_lock to be held. Currently only vcpu->mutex is held,

triggering lockdep warning:

=============================

WARNING: suspicious RCU usage in kvm_vcpu_gfn_to_memslot

6.12.59+ #3 Not tainted

include/linux/kvm_host.h:1062 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1

1 lock held by syz.5.1717/15100:

#0: ff1100002f4b00b0 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0x1d5/0x1590

Ca

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References