{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2025-37996",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2025-04-16T04:51:23.976Z",
        "datePublished": "2025-05-29T13:15:54.956Z",
        "dateUpdated": "2026-08-05T11:58:48.143Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T11:58:48.143Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Fix uninitialized memcache pointer in user_mem_abort()\n\nCommit fce886a60207 (\"KVM: arm64: Plumb the pKVM MMU in KVM\") made the\ninitialization of the local memcache variable in user_mem_abort()\nconditional, leaving a codepath where it is used uninitialized via\nkvm_pgtable_stage2_map().\n\nThis can fail on any path that requires a stage-2 allocation\nwithout transition via a permission fault or dirty logging.\n\nFix this by making sure that memcache is always valid."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
                        "baseScore": 8.8,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:L - The vulnerable code is the host kernel's stage-2 fault handler, reached through guest execution under KVM_RUN (or directly by a local user with /dev/kvm who builds their own VM); there is no network-facing path.\nAC:L - No race or unpredictable precondition is involved — an attacker controlling a guest can deterministically arrange a huge-block stage-2 mapping and then take a non-write permission fault (instruction fetch, or an NV shadow-S2 granule mismatch) so that `memcache` is consumed uninitialized on every attempt.\nPR:L - The attacker only needs code execution inside a guest VM, or unprivileged access to /dev/kvm on the host (commonly group- or world-accessible on Android, desktops and libvirt hosts); no host root is required.\nUI:N - The fault is raised by the guest's own memory access during normal vCPU execution, with no action needed from the host operator or any other user.\nS:C - The bug lets a guest corrupt host-kernel memory through the stage-2 page-table allocator, crossing from the VM's security authority into the hypervisor host — a guest-to-host boundary violation.\nC:H - `kvm_mmu_memory_cache_alloc()` performs `mc->objects[--mc->nobjs]` through the garbage pointer, an attacker-influenceable arbitrary read whose result is then mapped into the guest's stage-2 tables, exposing host memory contents to the guest.\nI:H - The uninitialized pointer yields wild writes (`--mc->nobjs`, and under pKVM `swap(mapping, cache->mapping)` followed by `mapping->gfn/pfn` stores) and causes arbitrary host memory to be installed as a guest stage-2 page table with matching `get_page`/`put_page` refcount manipulation — a host memory-corruption and control-flow-hijack primitive.\nA:H - In the ordinary case the wild dereference (or the `BUG_ON(!p)` in `kvm_mmu_memory_cache_alloc()`) oopses in the vCPU thread while holding the KVM fault lock, panicking the host kernel and taking down every VM on the machine."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "arch/arm64/kvm/mmu.c"
                    ],
                    "versions": [
                        {
                            "version": "fce886a6020734d6253c2c5a3bc285e385cc5496",
                            "lessThan": "a26d50f8a4a5049e956984797b5d0dedea4bbb18",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "fce886a6020734d6253c2c5a3bc285e385cc5496",
                            "lessThan": "157dbc4a321f5bb6f8b6c724d12ba720a90f1a7c",
                            "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/arm64/kvm/mmu.c"
                    ],
                    "versions": [
                        {
                            "version": "6.14",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.14",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.14.7",
                            "lessThanOrEqual": "6.14.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.15",
                            "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": "6.14",
                                    "versionEndExcluding": "6.14.7"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.14",
                                    "versionEndExcluding": "6.15"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/a26d50f8a4a5049e956984797b5d0dedea4bbb18"
                },
                {
                    "url": "https://git.kernel.org/stable/c/157dbc4a321f5bb6f8b6c724d12ba720a90f1a7c"
                }
            ],
            "title": "KVM: arm64: Fix uninitialized memcache pointer in user_mem_abort()",
            "x_generator": {
                "engine": "bippy-1.2.0"
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        }
    }
}