Skip to main content
cve.nowby Sazabi
← All vulnerabilities
CVE-2025-21779

KVM: x86: Reject Hyper-V's SEND_IPI hypercalls if local APIC isn't in-kernel

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.10.236, 5.15.179, 6.1.129, 6.6.79, 6.12.16, and 1 more
None on Exploit-DB, Metasploit or GitHub

Summary

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Reject Hyper-V's SEND_IPI hypercalls if local APIC isn't in-kernel Advertise support for Hyper-V's SEND_IPI and SEND_IPI_EX hypercalls if and only if the local API is emulated/virtualized by KVM, and explicitly reject said hypercalls if the local APIC is emulated in userspace, i.e. don't rely on userspace to opt-in to KVM_CAP_HYPERV_ENFORCE_CPUID. Rejecting SEND_IPI and SEND_IPI_EX fixes a NULL-pointer dereference if Hyper-V enlightenments are exposed to the guest without an in-kernel local APIC: dump_stack+0xbe/0xfd __kasan_report.cold+0x34/0x84 kasan_report+0x3a/0x50 __apic_accept_irq+0x3a/0x5c0 kvm_hv_send_ipi.isra.0+0x34e/0x820 kvm_hv_hypercall+0x8d9/0x9d0 kvm_emulate_hypercall+0x506/0x7e0 __vmx_handle_exit+0x283/0xb60 vmx_handle_exit+0x1d/0xd0 vcpu_enter_guest+0x16b0/0x24c0 vcpu_run+0xc0/0x550 kvm_arch_vcpu_ioctl_run+0x170/0x6d0 kvm_vcpu_ioctl+0x413/0xb20 __se_sys_ioctl+0x111/0x160 do_syscal1_64+0x30/0x40 entry_SYSCALL_64_after_hwframe+0x67/0xd1 Note, checking the sending vCPU is sufficient, as the per-VM irqchip_mode can't be modified after vCPUs are created, i.e. if one vCPU has an in-kernel local APIC, then all vCPUs have an in-kernel local APIC.

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • Linux Linux

    From 214ff83d4473a7757fa18a64dc7efe3b0e158486 · fixed in 61224533f2b61e252b03e214195d27d64b22989a; From 214ff83d4473a7757fa18a64dc7efe3b0e158486 · fixed in 45fa526b0f5a34492ed0536c3cdf88b78380e4de; From 214ff83d4473a7757fa18a64dc7efe3b0e158486 · fixed in 5393cf22312418262679eaadb130d608c75fe690; From 214ff83d4473a7757fa18a64dc7efe3b0e158486 · fixed in 874ff13c73c45ecb38cb82191e8c1d523f0dc81b; From 214ff83d4473a7757fa18a64dc7efe3b0e158486 · fixed in aca8be4403fb90db7adaf63830e27ebe787a76e8; From 214ff83d4473a7757fa18a64dc7efe3b0e158486 · fixed in ca29f58ca374c40a0e69c5306fc5c940a0069074; From 214ff83d4473a7757fa18a64dc7efe3b0e158486 · fixed in a8de7f100bb5989d9c3627d3a223ee1c863f3b69

  • Linux Linux

    4.20

  • KernelLinux

    From 4.20.0 · fixed in 5.10.236; From 5.11.0 · fixed in 5.15.179; From 5.16.0 · fixed in 6.1.129; From 6.2.0 · fixed in 6.6.79; From 6.7.0 · fixed in 6.12.16; From 6.13.0 · fixed in 6.13.4

References 7

git.kernel.org