{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-99177",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-09-25T10:25:14.399Z",
        "datePublished": "2026-10-28T10:35:31.315Z",
        "dateUpdated": "2026-10-31T12:44:45.294Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-10-31T12:44:45.294Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SEV: Fix page dirtying in sev_gmem_post_populate()\n\nset_page_dirty() requires that the caller holds some kind of lock to\nensure that the page's mapping does not concurrently go away.\nThat is not the case for a random page we got from get_user_pages_fast(),\nso use set_page_dirty_lock().\n\n[sean: tag for stable]"
                }
            ],
            "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 - Local ioctl(KVM_MEMORY_ENCRYPT_OP) follows kvm_vm_ioctl() → sev_mem_enc_ioctl() → snp_launch_update() → kvm_gmem_populate() → patched sev_gmem_post_populate(); the triggering CPUID page comes from the ioctl's userspace uaddr, not a network peer or guest.\nAC:L - The caller can supply a CPUID page that makes SEV_CMD_SNP_LAUNCH_UPDATE return SEV_RET_INVALID_PARAM and concurrently tear down its file-backed source mapping; the same attacker controls both sides of the set_page_dirty() race.\nPR:L - kvm_vm_ioctl() requires a same-mm VM fd and __sev_issue_cmd() requires a valid /dev/sev fd, but sev_mem_enc_ioctl() and snp_launch_update() perform no capability check; an unprivileged VMM account granted those device fds suffices.\nUI:N - The attacker creates and initializes the SNP VM, submits the rejected CPUID page, and races teardown of that page's mapping without any action by another user.\nS:U - The UAF occurs in the host kernel while servicing the host VMM's launch ioctl; it is not a guest-to-host escape because the guest has not begun executing on this pre-launch failure path.\nC:H - folio_mark_dirty() can invoke mapping->a_ops->dirty_folio through a freed inode-embedded address_space; grooming the stale object and exploiting the resulting kernel control-flow or mapping-state corruption can provide arbitrary host-kernel memory access.\nI:H - For buffer-backed pages, the stale callback can enter block_dirty_folio(), modify freed mapping locks and buffer state, then call __folio_mark_dirty() and __mark_inode_dirty() through reused objects, providing exploitable UAF writes and potential kernel code execution.\nA:H - The stale dirty_folio callback can dereference freed or poisoned a_ops, spinlocks, buffer heads, or host-inode state, causing a host kernel oops or panic."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "arch/x86/kvm/svm/sev.c"
                    ],
                    "versions": [
                        {
                            "version": "97cd21d57e9bd2da79845178d9250cfd19289cd4",
                            "lessThan": "184382f9852d433af21de96c334ecf43b8414ed8",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "97cd21d57e9bd2da79845178d9250cfd19289cd4",
                            "lessThan": "97818b2fa7082e940ddd36dab12a68615300e798",
                            "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/svm/sev.c"
                    ],
                    "versions": [
                        {
                            "version": "7.2",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "7.2",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.13",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "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": "7.2",
                                    "versionEndExcluding": "7.2.13"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "7.2",
                                    "versionEndExcluding": "7.3"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/184382f9852d433af21de96c334ecf43b8414ed8"
                },
                {
                    "url": "https://git.kernel.org/stable/c/97818b2fa7082e940ddd36dab12a68615300e798"
                }
            ],
            "title": "KVM: SEV: Fix page dirtying in sev_gmem_post_populate()",
            "x_generator": {
                "engine": "bippy-1.2.0"
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    }
}