{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2023-53756", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-12-08T01:18:04.280Z", "datePublished": "2025-12-08T01:19:17.081Z", "dateUpdated": "2026-05-11T19:51:04.572Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T19:51:04.572Z"}, "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"}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/kvm/vmx/hyperv.h", "arch/x86/kvm/vmx/vmx.c"], "versions": [{"version": "ceef7d10dfb6284d512c499292e6daa35ea83f90", "lessThan": "6baebcecf09acd19e2bab1c2911dcdba5d48a1dc", "status": "affected", "versionType": "git"}, {"version": "ceef7d10dfb6284d512c499292e6daa35ea83f90", "lessThan": "6e7bc50f97c9855da83f1478f722590defd45ff2", "status": "affected", "versionType": "git"}, {"version": "ceef7d10dfb6284d512c499292e6daa35ea83f90", "lessThan": "b2de2b4d4e007f9add46ea8dc06f781835e3ea9f", "status": "affected", "versionType": "git"}, {"version": "ceef7d10dfb6284d512c499292e6daa35ea83f90", "lessThan": "3ba95cc671c025d0d2a1c7d5e2930f0ff0980cf4", "status": "affected", "versionType": "git"}, {"version": "ceef7d10dfb6284d512c499292e6daa35ea83f90", "lessThan": "93827a0a36396f2fd6368a54a020f420c8916e9b", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/kvm/vmx/hyperv.h", "arch/x86/kvm/vmx/vmx.c"], "versions": [{"version": "4.18", "status": "affected"}, {"version": "0", "lessThan": "4.18", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.175", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.103", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.16", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.2.3", "lessThanOrEqual": "6.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.18", "versionEndExcluding": "5.10.175"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.18", "versionEndExcluding": "5.15.103"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.18", "versionEndExcluding": "6.1.16"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.18", "versionEndExcluding": "6.2.3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.18", "versionEndExcluding": "6.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/6baebcecf09acd19e2bab1c2911dcdba5d48a1dc"}, {"url": "https://git.kernel.org/stable/c/6e7bc50f97c9855da83f1478f722590defd45ff2"}, {"url": "https://git.kernel.org/stable/c/b2de2b4d4e007f9add46ea8dc06f781835e3ea9f"}, {"url": "https://git.kernel.org/stable/c/3ba95cc671c025d0d2a1c7d5e2930f0ff0980cf4"}, {"url": "https://git.kernel.org/stable/c/93827a0a36396f2fd6368a54a020f420c8916e9b"}], "title": "KVM: VMX: Fix crash due to uninitialized current_vmcs", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "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"}], "id": "CVE-2023-53756", "lastModified": "2026-04-15T00:35:42.020", "metrics": {}, "published": "2025-12-08T02:15:51.243", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "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"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Deferred"}

{"bugzilla": {"description": "kernel: KVM: VMX: Fix crash due to uninitialized current_vmcs", "id": "2419865", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2419865"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "details": ["In the Linux kernel, the following vulnerability has been resolved:\nKVM: VMX: Fix crash due to uninitialized current_vmcs\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.\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.\nThe manipulation of MSR bitmaps by callers happens only for vmcs01 so the\nsolution is to use vmx->vmcs01.vmcs instead of current_vmcs.\nBUG: kernel NULL pointer dereference, address: 0000000000000338\nPGD 4e1775067 P4D 0\nOops: 0002 [#1] PREEMPT SMP NOPTI\n...\nRIP: 0010:vmx_msr_bitmap_l01_changed+0x39/0x50 [kvm_intel]\n...\nCall Trace:\nvmx_disable_intercept_for_msr+0x36/0x260 [kvm_intel]\nvmx_vcpu_create+0xe6/0x540 [kvm_intel]\nkvm_arch_vcpu_create+0x1d1/0x2e0 [kvm]\nkvm_vm_ioctl_create_vcpu+0x178/0x430 [kvm]\nkvm_vm_ioctl+0x53f/0x790 [kvm]\n__x64_sys_ioctl+0x8a/0xc0\ndo_syscall_64+0x5c/0x90\nentry_SYSCALL_64_after_hwframe+0x63/0xcd"], "name": "CVE-2023-53756", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2025-12-08T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2023-53756\nhttps://nvd.nist.gov/vuln/detail/CVE-2023-53756\nhttps://lore.kernel.org/linux-cve-announce/2025120843-CVE-2023-53756-f234@gregkh/T"], "threat_severity": "Low"}

{}