CVE-2026-43214 (GCVE-0-2026-43214)
Vulnerability from cvelistv5
Published
2026-05-06 11:28
Modified
2026-08-05 12:26
Severity ?
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Add SRCU protection for reading PDPTRs in __get_sregs2() Add SRCU read-side protection when reading PDPTR registers in __get_sregs2(). Reading PDPTRs may trigger access to guest memory: kvm_pdptr_read() -> svm_cache_reg() -> load_pdptrs() -> kvm_vcpu_read_guest_page() -> kvm_vcpu_gfn_to_memslot() kvm_vcpu_gfn_to_memslot() dereferences memslots via __kvm_memslots(), which uses srcu_dereference_check() and requires either kvm->srcu or kvm->slots_lock to be held. Currently only vcpu->mutex is held, triggering lockdep warning: ============================= WARNING: suspicious RCU usage in kvm_vcpu_gfn_to_memslot 6.12.59+ #3 Not tainted include/linux/kvm_host.h:1062 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by syz.5.1717/15100: #0: ff1100002f4b00b0 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0x1d5/0x1590 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xf0/0x120 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x1e3/0x270 kernel/locking/lockdep.c:6824 __kvm_memslots include/linux/kvm_host.h:1062 [inline] __kvm_memslots include/linux/kvm_host.h:1059 [inline] kvm_vcpu_memslots include/linux/kvm_host.h:1076 [inline] kvm_vcpu_gfn_to_memslot+0x518/0x5e0 virt/kvm/kvm_main.c:2617 kvm_vcpu_read_guest_page+0x27/0x50 virt/kvm/kvm_main.c:3302 load_pdptrs+0xff/0x4b0 arch/x86/kvm/x86.c:1065 svm_cache_reg+0x1c9/0x230 arch/x86/kvm/svm/svm.c:1688 kvm_pdptr_read arch/x86/kvm/kvm_cache_regs.h:141 [inline] __get_sregs2 arch/x86/kvm/x86.c:11784 [inline] kvm_arch_vcpu_ioctl+0x3e20/0x4aa0 arch/x86/kvm/x86.c:6279 kvm_vcpu_ioctl+0x856/0x1590 virt/kvm/kvm_main.c:4663 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xbd/0x1d0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
References
Impacted products
Vendor Product Version
Linux Linux Version: 6dba940352038b56db9b591b172fb2ec76a5fd5e
Version: 6dba940352038b56db9b591b172fb2ec76a5fd5e
Version: 6dba940352038b56db9b591b172fb2ec76a5fd5e
Version: 6dba940352038b56db9b591b172fb2ec76a5fd5e
Version: 6dba940352038b56db9b591b172fb2ec76a5fd5e
Version: 6dba940352038b56db9b591b172fb2ec76a5fd5e
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/x86.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "f621ca24f9f489e226e22560761b04884984133b",
              "status": "affected",
              "version": "6dba940352038b56db9b591b172fb2ec76a5fd5e",
              "versionType": "git"
            },
            {
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              "versionType": "git"
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            {
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              "status": "affected",
              "version": "6dba940352038b56db9b591b172fb2ec76a5fd5e",
              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "6dba940352038b56db9b591b172fb2ec76a5fd5e",
              "versionType": "git"
            },
            {
              "lessThan": "b33f8d816950b10e7879cd8ffd7ae4b649ada4db",
              "status": "affected",
              "version": "6dba940352038b56db9b591b172fb2ec76a5fd5e",
              "versionType": "git"
            },
            {
              "lessThan": "95d848dc7e639988dbb385a8cba9b484607cf98c",
              "status": "affected",
              "version": "6dba940352038b56db9b591b172fb2ec76a5fd5e",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/x86.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.14"
            },
            {
              "lessThan": "5.14",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.165",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.128",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.75",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.16",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.165",
                  "versionStartIncluding": "5.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.128",
                  "versionStartIncluding": "5.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.75",
                  "versionStartIncluding": "5.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.16",
                  "versionStartIncluding": "5.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.6",
                  "versionStartIncluding": "5.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "5.14",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: Add SRCU protection for reading PDPTRs in __get_sregs2()\n\nAdd SRCU read-side protection when reading PDPTR registers in\n__get_sregs2().\n\nReading PDPTRs may trigger access to guest memory:\nkvm_pdptr_read() -\u003e svm_cache_reg() -\u003e load_pdptrs() -\u003e\nkvm_vcpu_read_guest_page() -\u003e kvm_vcpu_gfn_to_memslot()\n\nkvm_vcpu_gfn_to_memslot() dereferences memslots via __kvm_memslots(),\nwhich uses srcu_dereference_check() and requires either kvm-\u003esrcu or\nkvm-\u003eslots_lock to be held. Currently only vcpu-\u003emutex is held,\ntriggering lockdep warning:\n\n=============================\nWARNING: suspicious RCU usage in kvm_vcpu_gfn_to_memslot\n6.12.59+ #3 Not tainted\n\ninclude/linux/kvm_host.h:1062 suspicious rcu_dereference_check() usage!\n\nother info that might help us debug this:\n\nrcu_scheduler_active = 2, debug_locks = 1\n1 lock held by syz.5.1717/15100:\n #0: ff1100002f4b00b0 (\u0026vcpu-\u003emutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0x1d5/0x1590\n\nCall Trace:\n \u003cTASK\u003e\n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0xf0/0x120 lib/dump_stack.c:120\n lockdep_rcu_suspicious+0x1e3/0x270 kernel/locking/lockdep.c:6824\n __kvm_memslots include/linux/kvm_host.h:1062 [inline]\n __kvm_memslots include/linux/kvm_host.h:1059 [inline]\n kvm_vcpu_memslots include/linux/kvm_host.h:1076 [inline]\n kvm_vcpu_gfn_to_memslot+0x518/0x5e0 virt/kvm/kvm_main.c:2617\n kvm_vcpu_read_guest_page+0x27/0x50 virt/kvm/kvm_main.c:3302\n load_pdptrs+0xff/0x4b0 arch/x86/kvm/x86.c:1065\n svm_cache_reg+0x1c9/0x230 arch/x86/kvm/svm/svm.c:1688\n kvm_pdptr_read arch/x86/kvm/kvm_cache_regs.h:141 [inline]\n __get_sregs2 arch/x86/kvm/x86.c:11784 [inline]\n kvm_arch_vcpu_ioctl+0x3e20/0x4aa0 arch/x86/kvm/x86.c:6279\n kvm_vcpu_ioctl+0x856/0x1590 virt/kvm/kvm_main.c:4663\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:907 [inline]\n __se_sys_ioctl fs/ioctl.c:893 [inline]\n __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:893\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xbd/0x1d0 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nFound by Linux Verification Center (linuxtesting.org) with Syzkaller."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The vulnerable path is reached through local KVM ioctls on `/dev/kvm`, specifically creating a VM/vCPU and issuing `KVM_GET_SREGS2` on the vCPU fd. It is not reachable directly from network, adjacent, or physical input.\nAC:L - The attacker can control both sides of the race by issuing `KVM_GET_SREGS2` concurrently with memslot updates such as `KVM_SET_USER_MEMORY_REGION`. The needed PAE/SVM/NPT state is attacker-configurable in a reasonable KVM deployment.\nPR:L - Exploitation requires local access to KVM device fds, but the kernel path has no CAP_SYS_ADMIN-style check once `/dev/kvm` is accessible. This is low privilege rather than high privilege.\nUI:N - No victim action is required after the attacker has local KVM access. The attacker can create the VM, configure vCPU state, and trigger the racing ioctls directly.\nS:U - This is a host userspace-to-host kernel KVM ioctl vulnerability, not a guest-to-host escape path. The impacted kernel resources are within the same security scope.\nC:H - The missing SRCU protection can allow memslot metadata to be accessed after concurrent replacement or freeing. As a KVM memslot use-after-free condition, the higher defensible confidentiality impact is high.\nI:H - The same UAF-style race can allow attacker-shaped heap reuse of KVM metadata and corruption of KVM/kernel execution state. Following the required higher-severity rule for UAF memory corruption, integrity impact is high.\nA:H - At minimum, racing an unprotected memslot dereference can trigger kernel warnings, invalid pointer dereferences, or crashes. Kernel crash or oops impact is high availability."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:26:39.670Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/f621ca24f9f489e226e22560761b04884984133b"
        },
        {
          "url": "https://git.kernel.org/stable/c/708e20c66b2761d878a2bc3c7534e7f814e4dec5"
        },
        {
          "url": "https://git.kernel.org/stable/c/9f2bfea51151dfbb24b52f452eb3d5f5fe0e506e"
        },
        {
          "url": "https://git.kernel.org/stable/c/57536ff0a6bd69a5808d682925202babdb5ddc13"
        },
        {
          "url": "https://git.kernel.org/stable/c/b33f8d816950b10e7879cd8ffd7ae4b649ada4db"
        },
        {
          "url": "https://git.kernel.org/stable/c/95d848dc7e639988dbb385a8cba9b484607cf98c"
        }
      ],
      "title": "KVM: x86: Add SRCU protection for reading PDPTRs in __get_sregs2()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-43214",
    "datePublished": "2026-05-06T11:28:16.766Z",
    "dateReserved": "2026-05-01T14:12:55.993Z",
    "dateUpdated": "2026-08-05T12:26:39.670Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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