{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2022-49562",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2025-02-26T02:08:31.591Z",
        "datePublished": "2025-02-26T02:14:06.515Z",
        "dateUpdated": "2026-08-05T08:55:46.165Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T08:55:46.165Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: Use __try_cmpxchg_user() to update guest PTE A/D bits\n\nUse the recently introduced __try_cmpxchg_user() to update guest PTE A/D\nbits instead of mapping the PTE into kernel address space.  The VM_PFNMAP\npath is broken as it assumes that vm_pgoff is the base pfn of the mapped\nVMA range, which is conceptually wrong as vm_pgoff is the offset relative\nto the file and has nothing to do with the pfn.  The horrific hack worked\nfor the original use case (backing guest memory with /dev/mem), but leads\nto accessing \"random\" pfns for pretty much any other VM_PFNMAP case."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 7.8,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:L - Exploitation requires local access to /dev/kvm and KVM ioctls (KVM_CREATE_VM/VCPU, KVM_SET_USER_MEMORY_REGION, KVM_TRANSLATE or guest page walks); it is not reachable via network packets.\nAC:L - The attacker fully controls the VM_PFNMAP backing (e.g. io_uring SQE mmap), guest page-table contents, and the ioctl/page-walk trigger, and public reproducers reliably hit the bad memremap/CMPXCHG path.\nPR:L - /dev/kvm is usable by unprivileged local users (kvm group or equivalent); no root or init-namespace admin capability is required, as confirmed by the CVE-2022-1158 disclosure.\nUI:N - The attacker triggers the bug entirely from their own process via KVM and mmap syscalls; no victim action is required.\nS:U - A host userspace KVM client corrupts the host kernel in the same privilege domain; this is local privilege escalation, not a guest-to-host escape across a VM boundary.\nC:H - The bug writes to attacker-influenced wrong physical pages (demonstrated UAF/kernel corruption), which can be leveraged for privilege escalation and thus full confidentiality compromise.\nI:H - cmpxchg_gpte() performs an out-of-bounds CMPXCHG write into incorrectly computed physical memory, enabling arbitrary kernel memory corruption and potential control-flow hijacking.\nA:H - The erroneous physical write reliably causes kernel faults/UAF crashes (as shown by KASAN in the public reproducer), yielding high availability impact."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "arch/x86/kvm/mmu/paging_tmpl.h"
                    ],
                    "versions": [
                        {
                            "version": "bd53cb35a3e9adb73a834a36586e9ad80e877767",
                            "lessThan": "38b888911e8dc89b89d8147cfb1d2dbe6373bf78",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "bd53cb35a3e9adb73a834a36586e9ad80e877767",
                            "lessThan": "8089e5e1d18402fb8152d6b6815450a36fffa9b0",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "bd53cb35a3e9adb73a834a36586e9ad80e877767",
                            "lessThan": "f122dfe4476890d60b8c679128cd2259ec96a24c",
                            "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/mmu/paging_tmpl.h"
                    ],
                    "versions": [
                        {
                            "version": "5.2",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "5.2",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.17.13",
                            "lessThanOrEqual": "5.17.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.18.2",
                            "lessThanOrEqual": "5.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.19",
                            "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": "5.2",
                                    "versionEndExcluding": "5.17.13"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.2",
                                    "versionEndExcluding": "5.18.2"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.2",
                                    "versionEndExcluding": "5.19"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/38b888911e8dc89b89d8147cfb1d2dbe6373bf78"
                },
                {
                    "url": "https://git.kernel.org/stable/c/8089e5e1d18402fb8152d6b6815450a36fffa9b0"
                },
                {
                    "url": "https://git.kernel.org/stable/c/f122dfe4476890d60b8c679128cd2259ec96a24c"
                }
            ],
            "title": "KVM: x86: Use __try_cmpxchg_user() to update guest PTE A/D bits",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}