logo_clicknbuy.png

CVE-2024-55881 – “KVM AMD x86 Hypercall Detection Vulnerability”

The following table lists the changes that have been made to the
CVE-2024-55881 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution
of a vulnerability, and for identifying the most recent changes that may
impact the vulnerability’s severity, exploitability, or other characteristics.

  • New CVE Received
    by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Jan. 11, 2025

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved:

    KVM: x86: Play nice with protected guests in complete_hypercall_exit()

    Use is_64_bit_hypercall() instead of is_64_bit_mode() to detect a 64-bit
    hypercall when completing said hypercall. For guests with protected state,
    e.g. SEV-ES and SEV-SNP, KVM must assume the hypercall was made in 64-bit
    mode as the vCPU state needed to detect 64-bit mode is unavailable.

    Hacking the sev_smoke_test selftest to generate a KVM_HC_MAP_GPA_RANGE
    hypercall via VMGEXIT trips the WARN:

    ————[ cut here ]————
    WARNING: CPU: 273 PID: 326626 at arch/x86/kvm/x86.h:180 complete_hypercall_exit+0x44/0xe0 [kvm]
    Modules linked in: kvm_amd kvm … [last unloaded: kvm]
    CPU: 273 UID: 0 PID: 326626 Comm: sev_smoke_test Not tainted 6.12.0-smp–392e932fa0f3-feat #470
    Hardware name: Google Astoria/astoria, BIOS 0.20240617.0-0 06/17/2024
    RIP: 0010:complete_hypercall_exit+0x44/0xe0 [kvm]
    Call Trace:

    kvm_arch_vcpu_ioctl_run+0x2400/0x2720 [kvm]
    kvm_vcpu_ioctl+0x54f/0x630 [kvm]
    __se_sys_ioctl+0x6b/0xc0
    do_syscall_64+0x83/0x160
    entry_SYSCALL_64_after_hwframe+0x76/0x7e

    —[ end trace 0000000000000000 ]—
    Added Reference https://git.kernel.org/stable/c/0840d360a8909c722fb62459f42836afe32ededb
    Added Reference https://git.kernel.org/stable/c/22b5c2acd65dbe949032f619d4758a35a82fffc3
    Added Reference https://git.kernel.org/stable/c/3d2634ec0d1dbe8f4b511cf5261f327c6a76f4b6
    Added Reference https://git.kernel.org/stable/c/7ed4db315094963de0678a8adfd43c46471b9349
    Added Reference https://git.kernel.org/stable/c/9b42d1e8e4fe9dc631162c04caa69b0d1860b0f0
Share the Post:

Related Posts