{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-31702",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-03-09T15:48:24.132Z",
        "datePublished": "2026-05-01T13:56:01.601Z",
        "dateUpdated": "2026-06-14T17:43:43.186Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-06-14T17:43:43.186Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix use-after-free of sbi in f2fs_compress_write_end_io()\n\nIn f2fs_compress_write_end_io(), dec_page_count(sbi, type) can bring\nthe F2FS_WB_CP_DATA counter to zero, unblocking\nf2fs_wait_on_all_pages() in f2fs_put_super() on a concurrent unmount\nCPU. The unmount path then proceeds to call\nf2fs_destroy_page_array_cache(sbi), which destroys\nsbi->page_array_slab via kmem_cache_destroy(), and eventually\nkfree(sbi). Meanwhile, the bio completion callback is still executing:\nwhen it reaches page_array_free(sbi, ...), it dereferences\nsbi->page_array_slab — a destroyed slab cache — to call\nkmem_cache_free(), causing a use-after-free.\n\nThis is the same class of bug as CVE-2026-23234 (which fixed the\nequivalent race in f2fs_write_end_io() in data.c), but in the\ncompressed writeback completion path that was not covered by that fix.\n\nFix this by moving dec_page_count() to after page_array_free(), so\nthat all sbi accesses complete before the counter decrement that can\nunblock unmount. For non-last folios (where atomic_dec_return on\ncic->pending_pages is nonzero), dec_page_count is called immediately\nbefore returning — page_array_free is not reached on this path, so\nthere is no post-decrement sbi access. For the last folio,\npage_array_free runs while the F2FS_WB_CP_DATA counter is still\nnonzero (this folio has not yet decremented it), keeping sbi alive,\nand dec_page_count runs as the final operation."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/f2fs/compress.c"
                    ],
                    "versions": [
                        {
                            "version": "4c8ff7095bef64fc47e996a938f7d57f9e077da3",
                            "lessThan": "57bc678f36ac03281e877c6b84877b43f964143f",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4c8ff7095bef64fc47e996a938f7d57f9e077da3",
                            "lessThan": "ef57cd3329b40c739b9a2e1a8a21ecc4171c6280",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4c8ff7095bef64fc47e996a938f7d57f9e077da3",
                            "lessThan": "f5154cf3ce1c8193f0c1891d3769f62740cfe6fe",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4c8ff7095bef64fc47e996a938f7d57f9e077da3",
                            "lessThan": "c76cf339b87975ae5b2c06d2d774d5667d25a12a",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4c8ff7095bef64fc47e996a938f7d57f9e077da3",
                            "lessThan": "2c97dcb6147c8f7f25c629b93be1e69617de5d4a",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4c8ff7095bef64fc47e996a938f7d57f9e077da3",
                            "lessThan": "39d4ee19c1e7d753dd655aebee632271b171f43a",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/f2fs/compress.c"
                    ],
                    "versions": [
                        {
                            "version": "5.6",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "5.6",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.175",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.136",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.84",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.25",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0.2",
                            "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": "5.6",
                                    "versionEndExcluding": "6.1.175"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.6",
                                    "versionEndExcluding": "6.6.136"
                                },
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                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.6",
                                    "versionEndExcluding": "6.12.84"
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                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.6",
                                    "versionEndExcluding": "6.18.25"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.6",
                                    "versionEndExcluding": "7.0.2"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.6",
                                    "versionEndExcluding": "7.1"
                                }
                            ]
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                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/57bc678f36ac03281e877c6b84877b43f964143f"
                },
                {
                    "url": "https://git.kernel.org/stable/c/ef57cd3329b40c739b9a2e1a8a21ecc4171c6280"
                },
                {
                    "url": "https://git.kernel.org/stable/c/f5154cf3ce1c8193f0c1891d3769f62740cfe6fe"
                },
                {
                    "url": "https://git.kernel.org/stable/c/c76cf339b87975ae5b2c06d2d774d5667d25a12a"
                },
                {
                    "url": "https://git.kernel.org/stable/c/2c97dcb6147c8f7f25c629b93be1e69617de5d4a"
                },
                {
                    "url": "https://git.kernel.org/stable/c/39d4ee19c1e7d753dd655aebee632271b171f43a"
                }
            ],
            "title": "f2fs: fix use-after-free of sbi in f2fs_compress_write_end_io()",
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                "engine": "bippy-1.2.0"
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    }
}