{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-31458",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-03-09T15:48:24.092Z",
        "datePublished": "2026-04-22T13:53:50.883Z",
        "dateUpdated": "2026-05-11T22:09:07.003Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-05-11T22:09:07.003Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/sysfs: check contexts->nr before accessing contexts_arr[0]\n\nMultiple sysfs command paths dereference contexts_arr[0] without first\nverifying that kdamond->contexts->nr == 1.  A user can set nr_contexts to\n0 via sysfs while DAMON is running, causing NULL pointer dereferences.\n\nIn more detail, the issue can be triggered by privileged users like\nbelow.\n\nFirst, start DAMON and make contexts directory empty\n(kdamond->contexts->nr == 0).\n\n    # damo start\n    # cd /sys/kernel/mm/damon/admin/kdamonds/0\n    # echo 0 > contexts/nr_contexts\n\nThen, each of below commands will cause the NULL pointer dereference.\n\n    # echo update_schemes_stats > state\n    # echo update_schemes_tried_regions > state\n    # echo update_schemes_tried_bytes > state\n    # echo update_schemes_effective_quotas > state\n    # echo update_tuned_intervals > state\n\nGuard all commands (except OFF) at the entry point of\ndamon_sysfs_handle_cmd()."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "mm/damon/sysfs.c"
                    ],
                    "versions": [
                        {
                            "version": "0ac32b8affb5a384253dbb8339bd2d0e91add0b7",
                            "lessThan": "aba546061341b56e9ffb37e1eb661a3628b6ec12",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0ac32b8affb5a384253dbb8339bd2d0e91add0b7",
                            "lessThan": "1e8da792672481d603fa7cd0d815577220a3ee27",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0ac32b8affb5a384253dbb8339bd2d0e91add0b7",
                            "lessThan": "708033c231bd782858f4ddbb46ee874a5a5fbdab",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0ac32b8affb5a384253dbb8339bd2d0e91add0b7",
                            "lessThan": "bbe03ad3fb9e714191757ca7b41582f930be7be2",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0ac32b8affb5a384253dbb8339bd2d0e91add0b7",
                            "lessThan": "1bfe9fb5ed2667fb075682408b776b5273162615",
                            "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/damon/sysfs.c"
                    ],
                    "versions": [
                        {
                            "version": "5.18",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "5.18",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.131",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.80",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.21",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.19.11",
                            "lessThanOrEqual": "6.19.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0",
                            "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": "5.18",
                                    "versionEndExcluding": "6.6.131"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.18",
                                    "versionEndExcluding": "6.12.80"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.18",
                                    "versionEndExcluding": "6.18.21"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.18",
                                    "versionEndExcluding": "6.19.11"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.18",
                                    "versionEndExcluding": "7.0"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/aba546061341b56e9ffb37e1eb661a3628b6ec12"
                },
                {
                    "url": "https://git.kernel.org/stable/c/1e8da792672481d603fa7cd0d815577220a3ee27"
                },
                {
                    "url": "https://git.kernel.org/stable/c/708033c231bd782858f4ddbb46ee874a5a5fbdab"
                },
                {
                    "url": "https://git.kernel.org/stable/c/bbe03ad3fb9e714191757ca7b41582f930be7be2"
                },
                {
                    "url": "https://git.kernel.org/stable/c/1bfe9fb5ed2667fb075682408b776b5273162615"
                }
            ],
            "title": "mm/damon/sysfs: check contexts->nr before accessing contexts_arr[0]",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}