fkie_cve-2024-53196
Vulnerability from fkie_nvd
Published
2024-12-27 14:15
Modified
2024-12-27 14:15
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Don't retire aborted MMIO instruction Returning an abort to the guest for an unsupported MMIO access is a documented feature of the KVM UAPI. Nevertheless, it's clear that this plumbing has seen limited testing, since userspace can trivially cause a WARN in the MMIO return: WARNING: CPU: 0 PID: 30558 at arch/arm64/include/asm/kvm_emulate.h:536 kvm_handle_mmio_return+0x46c/0x5c4 arch/arm64/include/asm/kvm_emulate.h:536 Call trace: kvm_handle_mmio_return+0x46c/0x5c4 arch/arm64/include/asm/kvm_emulate.h:536 kvm_arch_vcpu_ioctl_run+0x98/0x15b4 arch/arm64/kvm/arm.c:1133 kvm_vcpu_ioctl+0x75c/0xa78 virt/kvm/kvm_main.c:4487 __do_sys_ioctl fs/ioctl.c:51 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:893 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x1e0/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x38/0x68 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x90/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 The splat is complaining that KVM is advancing PC while an exception is pending, i.e. that KVM is retiring the MMIO instruction despite a pending synchronous external abort. Womp womp. Fix the glaring UAPI bug by skipping over all the MMIO emulation in case there is a pending synchronous exception. Note that while userspace is capable of pending an asynchronous exception (SError, IRQ, or FIQ), it is still safe to retire the MMIO instruction in this case as (1) they are by definition asynchronous, and (2) KVM relies on hardware support for pending/delivering these exceptions instead of the software state machine for advancing PC.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1e46460efe1ef9a31748de7675ff8fe0d8601af2
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6af853cf5f897d55f42e9166f4db50e84e404fb3
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d0571c3add987bcb69c2ffd7a70c998bf8ce60fb
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e735a5da64420a86be370b216c269b5dd8e830e2
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ea6b5d98fea4ee8cb443ea98fda520909e90d30e
Impacted products
Vendor Product Version


To clipboard 

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Don\u0027t retire aborted MMIO instruction\n\nReturning an abort to the guest for an unsupported MMIO access is a\ndocumented feature of the KVM UAPI. Nevertheless, it\u0027s clear that this\nplumbing has seen limited testing, since userspace can trivially cause a\nWARN in the MMIO return:\n\n  WARNING: CPU: 0 PID: 30558 at arch/arm64/include/asm/kvm_emulate.h:536 kvm_handle_mmio_return+0x46c/0x5c4 arch/arm64/include/asm/kvm_emulate.h:536\n  Call trace:\n   kvm_handle_mmio_return+0x46c/0x5c4 arch/arm64/include/asm/kvm_emulate.h:536\n   kvm_arch_vcpu_ioctl_run+0x98/0x15b4 arch/arm64/kvm/arm.c:1133\n   kvm_vcpu_ioctl+0x75c/0xa78 virt/kvm/kvm_main.c:4487\n   __do_sys_ioctl fs/ioctl.c:51 [inline]\n   __se_sys_ioctl fs/ioctl.c:893 [inline]\n   __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:893\n   __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]\n   invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49\n   el0_svc_common+0x1e0/0x23c arch/arm64/kernel/syscall.c:132\n   do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151\n   el0_svc+0x38/0x68 arch/arm64/kernel/entry-common.c:712\n   el0t_64_sync_handler+0x90/0xfc arch/arm64/kernel/entry-common.c:730\n   el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598\n\nThe splat is complaining that KVM is advancing PC while an exception is\npending, i.e. that KVM is retiring the MMIO instruction despite a\npending synchronous external abort. Womp womp.\n\nFix the glaring UAPI bug by skipping over all the MMIO emulation in\ncase there is a pending synchronous exception. Note that while userspace\nis capable of pending an asynchronous exception (SError, IRQ, or FIQ),\nit is still safe to retire the MMIO instruction in this case as (1) they\nare by definition asynchronous, and (2) KVM relies on hardware support\nfor pending/delivering these exceptions instead of the software state\nmachine for advancing PC."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: KVM: arm64: No retire la instrucci\u00f3n MMIO abortada Devolver una interrupci\u00f3n al invitado para un acceso MMIO no compatible es una caracter\u00edstica documentada de KVM UAPI. Sin embargo, est\u00e1 claro que esta instalaci\u00f3n ha sido sometida a pruebas limitadas, ya que el espacio de usuario puede causar trivialmente una ADVERTENCIA en el retorno de MMIO: ADVERTENCIA: CPU: 0 PID: 30558 en arch/arm64/include/asm/kvm_emulate.h:536 kvm_handle_mmio_return+0x46c/0x5c4 arch/arm64/include/asm/kvm_emulate.h:536 Rastreo de llamadas: kvm_handle_mmio_return+0x46c/0x5c4 arch/arm64/include/asm/kvm_emulate.h:536 kvm_arch_vcpu_ioctl_run+0x98/0x15b4 arch/arm64/kvm/arm.c:1133 kvm_vcpu_ioctl+0x75c/0xa78 virt/kvm/kvm_main.c:4487 __do_sys_ioctl fs/ioctl.c:51 [en l\u00ednea] __se_sys_ioctl fs/ioctl.c:893 [en l\u00ednea] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:893 __invoke_syscall arch/arm64/kernel/syscall.c:35 [en l\u00ednea] anybody_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 nobody_svc_common+0x1e0/0x23c hate_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x38/0x68 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x90/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 El splat se queja de que KVM est\u00e1 avanzando la PC mientras hay una excepci\u00f3n pendiente, es decir, que KVM est\u00e1 retirando la instrucci\u00f3n MMIO a pesar de una interrupci\u00f3n externa sincr\u00f3nica pendiente. Womp womp. Corrija el evidente error de UAPI omitiendo toda la emulaci\u00f3n MMIO en caso de que haya una excepci\u00f3n sincr\u00f3nica pendiente. Tenga en cuenta que si bien el espacio de usuario puede dejar pendiente una excepci\u00f3n asincr\u00f3nica (SError, IRQ o FIQ), a\u00fan es seguro retirar la instrucci\u00f3n MMIO en este caso ya que (1) son asincr\u00f3nicas por definici\u00f3n y (2) KVM depende del soporte de hardware para dejar pendiente/entregar estas excepciones en lugar de la m\u00e1quina de estado del software para el avance de la PC."
    }
  ],
  "id": "CVE-2024-53196",
  "lastModified": "2024-12-27T14:15:27.267",
  "metrics": {},
  "published": "2024-12-27T14:15:27.267",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1e46460efe1ef9a31748de7675ff8fe0d8601af2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6af853cf5f897d55f42e9166f4db50e84e404fb3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d0571c3add987bcb69c2ffd7a70c998bf8ce60fb"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e735a5da64420a86be370b216c269b5dd8e830e2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ea6b5d98fea4ee8cb443ea98fda520909e90d30e"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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