{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-93196",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-09-17T16:02:15.092Z",
        "datePublished": "2026-09-17T16:12:19.125Z",
        "dateUpdated": "2026-10-21T12:52:16.262Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-10-21T12:52:16.262Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnvdimm: virtio_pmem: refcount requests for token lifetime\n\nKASAN reports slab-use-after-free in __wake_up_common():\nBUG: KASAN: slab-use-after-free in __wake_up_common+0x114/0x160\nRead of size 8 at addr ffff88810fdcb710 by task swapper/0/0\n\nCPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted\n6.19.0-next-20260220-00006-g1eae5f204ec3 #4 PREEMPT(full)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux\n1.17.0-2-2 04/01/2014\nCall Trace:\n <IRQ>\n dump_stack_lvl+0x6d/0xb0\n print_report+0x170/0x4e2\n ? __pfx__raw_spin_lock_irqsave+0x10/0x10\n ? __virt_addr_valid+0x1dc/0x380\n kasan_report+0xbc/0xf0\n ? __wake_up_common+0x114/0x160\n ? __wake_up_common+0x114/0x160\n __wake_up_common+0x114/0x160\n ? __pfx__raw_spin_lock_irqsave+0x10/0x10\n __wake_up+0x36/0x60\n virtio_pmem_host_ack+0x11d/0x3b0\n ? sched_balance_domains+0x29f/0xb00\n ? __pfx_virtio_pmem_host_ack+0x10/0x10\n ? _raw_spin_lock_irqsave+0x98/0x100\n ? __pfx__raw_spin_lock_irqsave+0x10/0x10\n vring_interrupt+0x1c9/0x5e0\n ? __pfx_vp_interrupt+0x10/0x10\n vp_vring_interrupt+0x87/0x100\n ? __pfx_vp_interrupt+0x10/0x10\n __handle_irq_event_percpu+0x17f/0x550\n ? __pfx__raw_spin_lock+0x10/0x10\n handle_irq_event+0xab/0x1c0\n handle_fasteoi_irq+0x276/0xae0\n __common_interrupt+0x65/0x130\n common_interrupt+0x78/0xa0\n </IRQ>\n\nvirtio_pmem_host_ack() wakes a request that has already been freed by the\nsubmitter.\n\nThis happens when the request token is still reachable via the virtqueue,\nbut virtio_pmem_flush() returns and frees it.\n\nFix the token lifetime by refcounting struct virtio_pmem_request.\nvirtio_pmem_flush() holds a submitter reference, and the virtqueue holds an\nextra reference once the request is queued. The completion path drops the\nvirtqueue reference, and the submitter drops its reference before\nreturning."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 8.4,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:L - virtio_pmem_host_ack() is the flush_queue callback registered in init_vq() and invoked from vring_interrupt() when the virtio-pmem backend completes a token; pmem_submit_bio() (REQ_PREFLUSH/REQ_FUA) and nd_pmem_remove() reach virtio_pmem_flush() only on that paravirtual device, not via a routable protocol message.\nAC:L - virtio_pmem_flush() kfree()s req_data after virtqueue_kick() fails while the token remains in req_vq, and on the success path kfree()s it while virtio_pmem_host_ack() still runs wake_up(&req_data->host_acked); a backend writing the used ring, or concurrent PREFLUSH/FUA bios (flush_lock only exists after a9ba6733), drives that lifetime hole.\nPR:N - virtio_pmem_host_ack() authenticates nothing and holds no guest credential. Host-initiated unplug runs virtio_pmem_remove()→nvdimm_bus_unregister()→nd_pmem_remove(), which calls nvdimm_flush(nd_region, NULL)→virtio_pmem_flush() with no capable() check before the token is queued on req_vq.\nUI:N - nd_pmem_remove()/nd_pmem_shutdown() submit virtio_pmem_flush() during teardown the backend/VMM initiates, and virtio_pmem_host_ack() then runs from vring_interrupt with no guest ioctl, mount, or file open; a local user of /dev/pmem likewise issues their own PREFLUSH/FUA bios.\nS:U - The freed object is a guest kmalloc struct virtio_pmem_request used only inside virtio_pmem_flush() and virtio_pmem_host_ack(); corruption stays in that guest kernel and is not a KVM/Xen guest-to-host escape or IOMMU/DMA bypass.\nC:H - virtio_pmem_host_ack() takes the freed token from virtqueue_get_buf() and writes req_data->done then wake_up(&req_data->host_acked) on the kfree'd slab; reuse of that virtio_pmem_request is a use-after-free read primitive once the object is sprayed.\nI:H - KASAN reports slab-use-after-free in __wake_up_common() from virtio_pmem_host_ack(): wake_up() walks the freed host_acked wait_queue_head, so a sprayed wait_queue_entry.func yields an indirect call and list-pointer write.\nA:H - KASAN reports slab-use-after-free in __wake_up_common() from virtio_pmem_host_ack() in vring_interrupt IRQ context on swapper/0, which oopses or panics the guest even when the UAF is not turned into a full exploit."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/nvdimm/nd_virtio.c",
                        "drivers/nvdimm/virtio_pmem.h"
                    ],
                    "versions": [
                        {
                            "version": "6e84200c0a2994b991259d19450eee561029bf70",
                            "lessThan": "41b2025709ec104a07d15540399809ae5851246e",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "6e84200c0a2994b991259d19450eee561029bf70",
                            "lessThan": "4691c137e9cbe76137d730a26d663d900ac7279b",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "6e84200c0a2994b991259d19450eee561029bf70",
                            "lessThan": "be072a5d5e35f4bdf2da22f600b5d6dc6c5ff491",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "6e84200c0a2994b991259d19450eee561029bf70",
                            "lessThan": "b1e740b9156621afd4c4aa66257f4dde8df1febe",
                            "status": "affected",
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                        },
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                            "version": "6e84200c0a2994b991259d19450eee561029bf70",
                            "lessThan": "e57140944b5a47a7fd5a142faab29a02af040bc8",
                            "status": "affected",
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                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/nvdimm/nd_virtio.c",
                        "drivers/nvdimm/virtio_pmem.h"
                    ],
                    "versions": [
                        {
                            "version": "5.3",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "5.3",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.160",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.112",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.52",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.6",
                            "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": "5.3",
                                    "versionEndExcluding": "6.6.160"
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                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.3",
                                    "versionEndExcluding": "6.12.112"
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                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.3",
                                    "versionEndExcluding": "6.18.52"
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                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.3",
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                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.3",
                                    "versionEndExcluding": "7.3"
                                }
                            ]
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                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/41b2025709ec104a07d15540399809ae5851246e"
                },
                {
                    "url": "https://git.kernel.org/stable/c/4691c137e9cbe76137d730a26d663d900ac7279b"
                },
                {
                    "url": "https://git.kernel.org/stable/c/be072a5d5e35f4bdf2da22f600b5d6dc6c5ff491"
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                    "url": "https://git.kernel.org/stable/c/b1e740b9156621afd4c4aa66257f4dde8df1febe"
                },
                {
                    "url": "https://git.kernel.org/stable/c/e57140944b5a47a7fd5a142faab29a02af040bc8"
                }
            ],
            "title": "nvdimm: virtio_pmem: refcount requests for token lifetime",
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}