{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-45837",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-05-13T15:03:33.077Z",
        "datePublished": "2026-05-27T09:24:32.833Z",
        "dateUpdated": "2026-06-14T17:46:01.781Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-06-14T17:46:01.781Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix use-after-free in arena_vm_close on fork\n\narena_vm_open() only bumps vml->mmap_count but never registers the\nchild VMA in arena->vma_list. The vml->vma always points at the\nparent VMA, so after parent munmap the pointer dangles. If the child\nthen calls bpf_arena_free_pages(), zap_pages() reads the stale\nvml->vma triggering use-after-free.\n\nFix this by preventing the arena VMA from being inherited across\nfork with VM_DONTCOPY, and preventing VMA splits via the may_split\ncallback.\n\nAlso reject mremap with a .mremap callback returning -EINVAL. A\nsame-size mremap(MREMAP_FIXED) on the full arena VMA reaches\ncopy_vma() through the following path:\n\n  check_prep_vma()       - returns 0 early: new_len == old_len\n                           skips VM_DONTEXPAND check\n  prep_move_vma()        - vm_start == old_addr and\n                           vm_end == old_addr + old_len\n                           so may_split is never called\n  move_vma()\n    copy_vma_and_data()\n      copy_vma()\n        vm_area_dup()    - copies vm_private_data (vml pointer)\n        vm_ops->open()   - bumps vml->mmap_count\n      vm_ops->mremap()   - returns -EINVAL, rollback unmaps new VMA\n\nThe refcount ensures the rollback's arena_vm_close does not free\nthe vml shared with the original VMA."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/bpf/arena.c"
                    ],
                    "versions": [
                        {
                            "version": "317460317a02a1af512697e6e964298dedd8a163",
                            "lessThan": "723b9fa930cc277c15ce6b9ec9feec828cfac9d7",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "317460317a02a1af512697e6e964298dedd8a163",
                            "lessThan": "d18099f19e53250f8ad2801498b88cec29d9107a",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "317460317a02a1af512697e6e964298dedd8a163",
                            "lessThan": "201128fcc7b213d27ab77bc4e89488b41796480f",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "317460317a02a1af512697e6e964298dedd8a163",
                            "lessThan": "4fddde2a732de60bb97e3307d4eb69ac5f1d2b74",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/bpf/arena.c"
                    ],
                    "versions": [
                        {
                            "version": "6.9",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.9",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.88",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.30",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0.7",
                            "lessThanOrEqual": "7.0.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1",
                            "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": "6.9",
                                    "versionEndExcluding": "6.12.88"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.9",
                                    "versionEndExcluding": "6.18.30"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.9",
                                    "versionEndExcluding": "7.0.7"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.9",
                                    "versionEndExcluding": "7.1"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/723b9fa930cc277c15ce6b9ec9feec828cfac9d7"
                },
                {
                    "url": "https://git.kernel.org/stable/c/d18099f19e53250f8ad2801498b88cec29d9107a"
                },
                {
                    "url": "https://git.kernel.org/stable/c/201128fcc7b213d27ab77bc4e89488b41796480f"
                },
                {
                    "url": "https://git.kernel.org/stable/c/4fddde2a732de60bb97e3307d4eb69ac5f1d2b74"
                }
            ],
            "title": "bpf: Fix use-after-free in arena_vm_close on fork",
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                "engine": "bippy-1.2.0"
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    }
}