{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-31484",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-03-09T15:48:24.101Z",
        "datePublished": "2026-04-22T13:54:10.223Z",
        "dateUpdated": "2026-08-05T12:22:59.333Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:22:59.333Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/fdinfo: fix OOB read in SQE_MIXED wrap check\n\n__io_uring_show_fdinfo() iterates over pending SQEs and, for 128-byte\nSQEs on an IORING_SETUP_SQE_MIXED ring, needs to detect when the second\nhalf of the SQE would be past the end of the sq_sqes array. The current\ncheck tests (++sq_head & sq_mask) == 0, but sq_head is only incremented\nwhen a 128-byte SQE is encountered, not on every iteration. The actual\narray index is sq_idx = (i + sq_head) & sq_mask, which can be sq_mask\n(the last slot) while the wrap check passes.\n\nFix by checking sq_idx directly. Keep the sq_head increment so the loop\nstill skips the second half of the 128-byte SQE on the next iteration."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
                        "baseScore": 7.1,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:L - The vulnerable path is reached locally by creating an io_uring instance and reading its procfs fdinfo entry; there is no network or adjacent attack surface.\nAC:L - The attacker controls the ring setup flags, SQ tail, SQ array mapping, and 128-byte SQE opcode needed to place a mixed SQE at the last physical slot. No race or external timing condition is required, and transient lock contention can be retried.\nPR:L - A normal unprivileged local user can use io_uring when the default io_uring sysctl allows it and can read /proc/self/fdinfo for its own fd. No real root or init-namespace capability is required.\nUI:N - The attacker triggers the bug by reading their own fdinfo file. No victim action is needed.\nS:U - The issue is a local kernel memory access bug within the same kernel security authority. It does not cross a VM, IOMMU, or other separate security scope boundary.\nC:H - The bug prints the second half of a 128-byte SQE by dereferencing up to 64 bytes past the SQE array, exposing adjacent kernel memory through procfs. The leak is attacker-triggerable and repeatable, so the highest defensible confidentiality impact is high.\nI:N - The vulnerable operation is an out-of-bounds read used for fdinfo printing and does not write to kernel memory or directly modify protected state.\nA:H - The same out-of-bounds kernel dereference can cross the end of the SQE allocation or a vmap-backed region and fault/oops depending on allocation layout. An unprivileged attacker can repeatedly trigger the path, so availability impact is high."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "io_uring/fdinfo.c"
                    ],
                    "versions": [
                        {
                            "version": "1cba30bf9fdd6c982708f3587f609a30c370d889",
                            "lessThan": "ba21ab247a5be5382da7464b95afbe5f0e9aa503",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1cba30bf9fdd6c982708f3587f609a30c370d889",
                            "lessThan": "5170efd9c344c68a8075dcb8ed38d3f8a60e7ed4",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "io_uring/fdinfo.c"
                    ],
                    "versions": [
                        {
                            "version": "6.19",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.19",
                            "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": "6.19",
                                    "versionEndExcluding": "6.19.11"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.19",
                                    "versionEndExcluding": "7.0"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/ba21ab247a5be5382da7464b95afbe5f0e9aa503"
                },
                {
                    "url": "https://git.kernel.org/stable/c/5170efd9c344c68a8075dcb8ed38d3f8a60e7ed4"
                }
            ],
            "title": "io_uring/fdinfo: fix OOB read in SQE_MIXED wrap check",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}