{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-99256",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-09-25T10:25:14.404Z",
        "datePublished": "2026-11-03T11:25:14.077Z",
        "dateUpdated": "2026-11-03T11:40:45.109Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-11-03T11:40:45.109Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm cache: fix issue with background work locking\n\ndm cache used a rw_semaphore for background_work_lock. Write locks on\nrw_semaphores have strict owner semantics, but there was no guarantee\nthat the process that locked background_work_lock was the same process\nthat unlocked it. This can be easily seen using a kernel compiled with\nCONFIG_DEBUG_RWSEMS. Given a dm cache device <cache>, run: 'dmsetup\nsuspend <cache> && dmsetup resume <cache>'. This will trigger a kernel\nwarning:\n\nDEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE))\n\ntriggered by cache_resume(). To fix this, switch from a rw_semaphore to\na spinlock and a wait queue. dm cache already has a wait queue and\nassociated counter, migration_wait and nr_allocated_migrations, that was\ngetting woken up when background work was getting completed, but wasn't\nactually used by anything. This is replaced by the background_work queue\nand counter."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/md/dm-cache-target.c"
                    ],
                    "versions": [
                        {
                            "version": "b29d4986d0da1a27cd35917cdb433672f5c95d7f",
                            "lessThan": "0c7a8cad7c96012a9157a189649e569d0390f384",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "b29d4986d0da1a27cd35917cdb433672f5c95d7f",
                            "lessThan": "f5db935d257023c3ef410bd39163b949b0e5a55d",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "b29d4986d0da1a27cd35917cdb433672f5c95d7f",
                            "lessThan": "6290507ecc0dd6dd40759729cbbbd49b1d2a63c4",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "b29d4986d0da1a27cd35917cdb433672f5c95d7f",
                            "lessThan": "8433fd005c25fd127021f67c9144a879fb585572",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "b29d4986d0da1a27cd35917cdb433672f5c95d7f",
                            "lessThan": "2f2cfa16dd0f4179bb988139dd37d00a42324f6c",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "b29d4986d0da1a27cd35917cdb433672f5c95d7f",
                            "lessThan": "73df2ff409f3db95029982fe3656329568e3715d",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "b29d4986d0da1a27cd35917cdb433672f5c95d7f",
                            "lessThan": "104f09e02038b0fc6bbb718b3976af029e15c1d0",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "b29d4986d0da1a27cd35917cdb433672f5c95d7f",
                            "lessThan": "bc9781c0247de107876f32929f1637db93a42b34",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/md/dm-cache-target.c"
                    ],
                    "versions": [
                        {
                            "version": "4.12",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "4.12",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.10.273",
                            "lessThanOrEqual": "5.10.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.15.224",
                            "lessThanOrEqual": "5.15.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.191",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.161",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.115",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.59",
                            "lessThanOrEqual": "6.18.*",
                            "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": "4.12",
                                    "versionEndExcluding": "5.10.273"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.12",
                                    "versionEndExcluding": "5.15.224"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.12",
                                    "versionEndExcluding": "6.1.191"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.12",
                                    "versionEndExcluding": "6.6.161"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.12",
                                    "versionEndExcluding": "6.12.115"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.12",
                                    "versionEndExcluding": "6.18.59"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.12",
                                    "versionEndExcluding": "7.2.13"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.12",
                                    "versionEndExcluding": "7.3"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/0c7a8cad7c96012a9157a189649e569d0390f384"
                },
                {
                    "url": "https://git.kernel.org/stable/c/f5db935d257023c3ef410bd39163b949b0e5a55d"
                },
                {
                    "url": "https://git.kernel.org/stable/c/6290507ecc0dd6dd40759729cbbbd49b1d2a63c4"
                },
                {
                    "url": "https://git.kernel.org/stable/c/8433fd005c25fd127021f67c9144a879fb585572"
                },
                {
                    "url": "https://git.kernel.org/stable/c/2f2cfa16dd0f4179bb988139dd37d00a42324f6c"
                },
                {
                    "url": "https://git.kernel.org/stable/c/73df2ff409f3db95029982fe3656329568e3715d"
                },
                {
                    "url": "https://git.kernel.org/stable/c/104f09e02038b0fc6bbb718b3976af029e15c1d0"
                },
                {
                    "url": "https://git.kernel.org/stable/c/bc9781c0247de107876f32929f1637db93a42b34"
                }
            ],
            "title": "dm cache: fix issue with background work locking",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}