{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-74481",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-08-15T05:44:03.904Z",
        "datePublished": "2026-08-15T12:27:14.441Z",
        "dateUpdated": "2026-10-16T19:05:48.983Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-19T16:37:36.090Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/page_reporting: use system_freezable_wq to fix UAF during suspend\n\nDuring PM freeze (e.g.  S3 suspend or S4 hibernation), device drivers like\nvirtio_balloon reset their underlying virtio devices and delete their\nvirtqueues via vdev->config->del_vqs().\n\nHowever, page reporting work (page_reporting_process) was scheduled on the\nglobal system_wq.  Because system_wq lacks the WQ_FREEZABLE flag, the PM\nfreezer skips it, leaving page_reporting_process active during suspend.\n\nIf pages are freed into the buddy allocator while suspending (for example,\nwhen core MM invokes the balloon shrinker during S4 hibernation image\nsaving), page reporting triggers virtballoon_free_page_report() on deleted\nvirtqueues, resulting in a Use-After-Free / General Protection Fault:\n\n    [  196.795226] general protection fault, probably for non-canonical address 0xaa1436fe70dae6df: 0000 [#1] SMP NOPTI\n    [  196.825967] Workqueue: events page_reporting_process\n    [  196.831038] RIP: 0010:virtqueue_add_split+0x233/0x4c0 [virtio_ring]\n    [  196.927073] virtballoon_free_page_report+0x3a/0xe0 [virtio_balloon]\n    [  196.946943] page_reporting_process+0x370/0x4f0\n\nFix this by switching page reporting work to system_freezable_wq.  This\nensures that the PM freezer pauses page_reporting_process before device\ndrivers destroy their reporting virtqueues.  Because the reporting worker\nis frozen, memory reclamation/freeing (e.g.  via shrinker execution) can\nsafely return pages to MM during freeze without triggering unfrozen\nreporting work on deleted virtqueues.\n\nThis aligns with the driver's existing design. The comment in\nvirtballoon_freeze() states:\n    /*\n     * The workqueue is already frozen by the PM core before this\n     * function is called.\n     */\n\nTesting:\nI have verified these fixes using Google’s virtualization infrastructure\nby running continuous suspend/resume iterations (40+ cycles) while\nchurning memory using stress-ng (`stress-ng --vm 4 --vm-bytes 60%\n--timeout 1`) to constantly create free pages for the buddy allocator.  We\nalso set the `page_reporting_order` parameter to 0 to make the page\nreporting worker highly sensitive, forcing it to pick up any 4K free\npages.  This confirmed that the UAF crashes are no longer reproducible."
                }
            ],
            "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 - The UAF is reached only through local PM suspend/hibernation and guest memory-free paths (__free_one_page -> page_reporting_notify_free -> page_reporting_process -> virtballoon_free_page_report); it is not reachable via network protocols or remote packet handling.\nAC:L - An attacker with local access can reliably drive the race by churning memory (e.g. stress-ng) to flood page-reporting work while triggering or awaiting S3/S4 suspend, as demonstrated in the fix commit's reproduction on virtio-balloon VMs.\nPR:L - No real-root capability is required to exercise the memory-free entry path (normal unprivileged mmap/malloc/free syscalls), and many desktop deployments allow session users to initiate suspend via logind/polkit without full init-namespace root.\nUI:N - Exploitation does not require a separate victim action beyond the attacker (or system policy) initiating suspend/hibernation; automated cloud/VM suspend-resume cycles and scripted PM transitions suffice without interactive victim cooperation.\nS:U - Impact is confined to guest kernel memory corruption and crash inside the virtio-balloon/page-reporting subsystem; it does not cross a VM/host, IOMMU, or sandbox security boundary to affect resources outside the kernel's own authority.\nC:H - This is a kernel heap use-after-free on freed virtqueue metadata accessed through virtqueue_add_split; UAF of kernel objects can be leveraged for arbitrary kernel memory read/info disclosure beyond the observed GPF crash.\nI:H - UAF on virtqueue/vring kernel structures during virtqueue_add_split provides a memory-corruption primitive that can be developed into controlled kernel writes or code execution, not merely a benign crash.\nA:H - The bug provably causes a kernel general protection fault/oops in page_reporting_process during suspend (Workqueue: events), crashing or destabilizing the system and denying availability on every affected suspend/hibernation cycle."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "mm/page_reporting.c"
                    ],
                    "versions": [
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                            "version": "36e66c554b5c6a9d17a229faca7a61693527b0bd",
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                            "status": "affected",
                            "versionType": "git"
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                            "lessThan": "992f270fd808338fbae1f498a5e325e7e2e20368",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "36e66c554b5c6a9d17a229faca7a61693527b0bd",
                            "lessThan": "f978048326570047e8216e81a67f9c71ef2bb1b1",
                            "status": "affected",
                            "versionType": "git"
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                            "status": "affected",
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                            "status": "affected",
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                            "version": "36e66c554b5c6a9d17a229faca7a61693527b0bd",
                            "lessThan": "0b45f6927a14914ff685fe0e6f9d11232a1e03df",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "mm/page_reporting.c"
                    ],
                    "versions": [
                        {
                            "version": "5.7",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "5.7",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.10.265",
                            "lessThanOrEqual": "5.10.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.15.216",
                            "lessThanOrEqual": "5.15.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.183",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.151",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.103",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.44",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1.8",
                            "lessThanOrEqual": "7.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
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                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.7",
                                    "versionEndExcluding": "5.10.265"
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            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/a4c60046052777ca1dcc83fe3ece2a5136b301f1"
                },
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                    "url": "https://git.kernel.org/stable/c/b2c094e98f8bb823b3ae475f7169fe2091c40c6d"
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                },
                {
                    "url": "https://git.kernel.org/stable/c/0b45f6927a14914ff685fe0e6f9d11232a1e03df"
                }
            ],
            "title": "mm/page_reporting: use system_freezable_wq to fix UAF during suspend",
            "x_generator": {
                "engine": "bippy-1.2.0"
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        "adp": [
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                "metrics": [
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                            "type": "ssvc",
                            "content": {
                                "id": "CVE-2026-74481",
                                "role": "CISA Coordinator",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
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                                    },
                                    {
                                        "Technical Impact": "total"
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                                "version": "2.0.3",
                                "timestamp": "2026-10-16T18:57:45.101951Z"
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}