CVE-2023-53756
In the Linux kernel, the following vulnerability has been resolved:
KVM: VMX: Fix crash due to uninitialized current_vmcs
KVM enables 'Enlightened VMCS' and 'Enlightened MSR Bitmap' when running as a nested hypervisor on top of Hyper-V. When MSR bitmap is updated, evmcs_touch_msr_bitmap function uses current_vmcs per-cpu variable to mark that the msr bitmap was changed.
vmx_vcpu_create() modifies the msr bitmap via vmx_disable_intercept_for_msr -> vmx_msr_bitmap_l01_changed which in the end calls this function.
Leer descripción completaMostrar menos
The function checks for current_vmcs if it is null but the check is insufficient because current_vmcs is not initialized. Because of this, the code might incorrectly write to the structure pointed by current_vmcs value left by another task. Preemption is not disabled, the current task can be preempted and moved to another CPU while current_vmcs is accessed multiple times from evmcs_touch_msr_bitmap() which leads to crash.
The manipulation of MSR bitmaps by callers happens only for vmcs01 so the solution is to use vmx->vmcs01.vmcs instead of current_vmcs.
Detalles técnicos trazas, registros y código del informe original
BUG: kernel NULL pointer dereference, address: 0000000000000338 PGD 4e1775067 P4D 0 Oops: 0002 [#1] PREEMPT SMP NOPTI ... RIP: 0010:vmx_msr_bitmap_l01_changed+0x39/0x50 [kvm_intel] ... Call Trace: vmx_disable_intercept_for_msr+0x36/0x260 [kvm_intel] vmx_vcpu_create+0xe6/0x540 [kvm_intel] kvm_arch_vcpu_create+0x1d1/0x2e0 [kvm] kvm_vm_ioctl_create_vcpu+0x178/0x430 [kvm] kvm_vm_ioctl+0x53f/0x790 [kvm] __x64_sys_ioctl+0x8a/0xc0 do_syscall_64+0x5c/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd
CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.19%
- Percentil entre todas las CVEs puntuadas: 8
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
- https://git.kernel.org/stable/c/3ba95cc671c025d0d2a1c7d5e2930f0ff0980cf4
- https://git.kernel.org/stable/c/6baebcecf09acd19e2bab1c2911dcdba5d48a1dc
- https://git.kernel.org/stable/c/6e7bc50f97c9855da83f1478f722590defd45ff2
- https://git.kernel.org/stable/c/93827a0a36396f2fd6368a54a020f420c8916e9b
- https://git.kernel.org/stable/c/b2de2b4d4e007f9add46ea8dc06f781835e3ea9f
JSON original (NVD)
Mostrar
{
"id": "CVE-2023-53756",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "ceef7d10dfb6284d512c499292e6daa35ea83f90",
"lessThan": "6baebcecf09acd19e2bab1c2911dcdba5d48a1dc",
"versionType": "git"
},
{
"status": "affected",
"version": "ceef7d10dfb6284d512c499292e6daa35ea83f90",
"lessThan": "6e7bc50f97c9855da83f1478f722590defd45ff2",
"versionType": "git"
},
{
"status": "affected",
"version": "ceef7d10dfb6284d512c499292e6daa35ea83f90",
"lessThan": "b2de2b4d4e007f9add46ea8dc06f781835e3ea9f",
"versionType": "git"
},
{
"status": "affected",
"version": "ceef7d10dfb6284d512c499292e6daa35ea83f90",
"lessThan": "3ba95cc671c025d0d2a1c7d5e2930f0ff0980cf4",
"versionType": "git"
},
{
"status": "affected",
"version": "ceef7d10dfb6284d512c499292e6daa35ea83f90",
"lessThan": "93827a0a36396f2fd6368a54a020f420c8916e9b",
"versionType": "git"
}
],
"programFiles": [
"arch/x86/kvm/vmx/hyperv.h",
"arch/x86/kvm/vmx/vmx.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.18"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.18",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.175",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.103",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.16",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.2.3",
"versionType": "semver",
"lessThanOrEqual": "6.2.*"
},
{
"status": "unaffected",
"version": "6.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"arch/x86/kvm/vmx/hyperv.h",
"arch/x86/kvm/vmx/vmx.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2025-12-08T02:15:51.243",
"references": [
{
"url": "https://git.kernel.org/stable/c/3ba95cc671c025d0d2a1c7d5e2930f0ff0980cf4",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/6baebcecf09acd19e2bab1c2911dcdba5d48a1dc",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/6e7bc50f97c9855da83f1478f722590defd45ff2",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/93827a0a36396f2fd6368a54a020f420c8916e9b",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/b2de2b4d4e007f9add46ea8dc06f781835e3ea9f",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Deferred",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: VMX: Fix crash due to uninitialized current_vmcs\n\nKVM enables 'Enlightened VMCS' and 'Enlightened MSR Bitmap' when running as\na nested hypervisor on top of Hyper-V. When MSR bitmap is updated,\nevmcs_touch_msr_bitmap function uses current_vmcs per-cpu variable to mark\nthat the msr bitmap was changed.\n\nvmx_vcpu_create() modifies the msr bitmap via vmx_disable_intercept_for_msr\n-> vmx_msr_bitmap_l01_changed which in the end calls this function. The\nfunction checks for current_vmcs if it is null but the check is\ninsufficient because current_vmcs is not initialized. Because of this, the\ncode might incorrectly write to the structure pointed by current_vmcs value\nleft by another task. Preemption is not disabled, the current task can be\npreempted and moved to another CPU while current_vmcs is accessed multiple\ntimes from evmcs_touch_msr_bitmap() which leads to crash.\n\nThe manipulation of MSR bitmaps by callers happens only for vmcs01 so the\nsolution is to use vmx->vmcs01.vmcs instead of current_vmcs.\n\n BUG: kernel NULL pointer dereference, address: 0000000000000338\n PGD 4e1775067 P4D 0\n Oops: 0002 [#1] PREEMPT SMP NOPTI\n ...\n RIP: 0010:vmx_msr_bitmap_l01_changed+0x39/0x50 [kvm_intel]\n ...\n Call Trace:\n vmx_disable_intercept_for_msr+0x36/0x260 [kvm_intel]\n vmx_vcpu_create+0xe6/0x540 [kvm_intel]\n kvm_arch_vcpu_create+0x1d1/0x2e0 [kvm]\n kvm_vm_ioctl_create_vcpu+0x178/0x430 [kvm]\n kvm_vm_ioctl+0x53f/0x790 [kvm]\n __x64_sys_ioctl+0x8a/0xc0\n do_syscall_64+0x5c/0x90\n entry_SYSCALL_64_after_hwframe+0x63/0xcd"
}
],
"lastModified": "2026-06-17T06:46:00.940",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}