CVE-2026-64031

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-64031", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.028Z", "datePublished": "2026-07-19T15:39:21.609Z", "dateUpdated": "2026-09-14T11:58:35.405Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-09-14T11:58:35.405Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nerofs: fix managed cache race for unaligned extents\n\nAfter unaligned compressed extents were introduced, the following race\ncould occur:\n\n[Thread 1] [Thread 2]\n(z_erofs_fill_bio_vec)\n<handle a Z_EROFS_PREALLOCATED_FOLIO folio>\n...\nfilemap_add_folio (1)\n (z_erofs_bind_cache)\n <the same folio is found..>\n ..\n ..\nfolio_attach_private (2)\n filemap_add_folio (3) again\n\nSince (1) is executed but (2) hasn't been executed yet, it's possible\nthat another thread finds the same managed folio in z_erofs_bind_cache()\nfor a different pcluster and calls filemap_add_folio() again since\nfolio->private is still Z_EROFS_PREALLOCATED_FOLIO.\n\nFix this by explicitly clearing folio->private before making the folio\nvisible in the managed cache so that another pcluster can simply wait\non the locked managed folio as what we did for other shared cases [1].\n\nThis only impacts unaligned data compression (`-E48bit` with zstd,\nfor example).\n\n[1] Commit 9e2f9d34dd12 (\"erofs: handle overlapped pclusters out of\n crafted images properly\") was originally introduced to handle crafted\n overlapped extents, but it addresses unaligned extents as well."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The bug is reached only through local VFS read paths (`read`/`pread`/`mmap` faults) on a mounted EROFS volume, flowing through `z_erofs_read_folio`/`z_erofs_readahead` \u2192 `z_erofs_runqueue` \u2192 `z_erofs_submit_queue` \u2192 `z_erofs_fill_bio_vec` and `z_erofs_bind_cache`. There is no network-facing handler; exploitation requires local filesystem access.\nAC:L - The race is between concurrent read/decompress threads that the attacker fully controls by issuing parallel reads against a crafted image with overlapping unaligned compressed extents. No timing or layout conditions outside attacker control are required beyond crafting the image and spawning concurrent I/O.\nPR:L - Triggering the vulnerable managed-cache path requires mounting a crafted EROFS image with unaligned zstd extents, which is achievable with CAP_SYS_ADMIN inside an unprivileged user namespace (`unshare -Urn`) plus loop mount. After mount, only normal unprivileged file read access is needed to hit the race.\nUI:N - Once the attacker can mount the crafted image (e.g., via user namespace), exploitation is fully automated through concurrent reads and requires no additional victim interaction such as opening a specific application or clicking a link.\nS:U - Impact is confined to kernel memory corruption and privilege escalation within the same kernel/host security boundary; this is not a VM escape, IOMMU bypass, or cross-authority sandbox breakout.\nC:H - The race leaves managed folios visible in the page cache while `folio->private` still marks them preallocated, allowing duplicate `filemap_add_folio` and conflicting `folio_attach_private`/`folio_detach_private` bindings to different pclusters\u2014classic page-cache corruption that can yield arbitrary kernel memory disclosure via confused folio ownership.\nI:H - Associating one managed folio with multiple pclusters corrupts `folio->private` and compressed-bvec references, creating use-after-free/refcount confusion in the managed cache that is exploitable for arbitrary kernel writes or control-flow hijack, not merely a benign error return.\nA:H - The corrupted managed-cache state can cause kernel oops/panic, hung tasks, or deadlock (similar overlapped-pcluster crafted-image failures previously caused syzbot hangs), and any successful UAF in this path also implies high availability impact even before full exploitation."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/erofs/zdata.c"], "versions": [{"version": "722f0fcdb0bb7d12a5c6d9460b9a7de1f735f36d", "lessThan": "2718cdb6db0fdbe375e61f2980aada27bafb323e", "status": "affected", "versionType": "git"}, {"version": "7361d1e3763baaf7b9349c576137851458ad38d1", "lessThan": "425d32d6288d7d845e486af9419bbedccd8c9103", "status": "affected", "versionType": "git"}, {"version": "7361d1e3763baaf7b9349c576137851458ad38d1", "lessThan": "038166f873c4caf6e85cfd4ea0c5a5ba297b4e8b", "status": "affected", "versionType": "git"}, {"version": "7361d1e3763baaf7b9349c576137851458ad38d1", "lessThan": "649932fc3815eda2f24eb4de4b3a5e94886ee0b9", "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/erofs/zdata.c"], "versions": [{"version": "6.15", "status": "affected"}, {"version": "0", "lessThan": "6.15", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.34", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0.11", "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": "6.15", "versionEndExcluding": "6.18.34"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "7.0.11"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "7.1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/2718cdb6db0fdbe375e61f2980aada27bafb323e"}, {"url": "https://git.kernel.org/stable/c/425d32d6288d7d845e486af9419bbedccd8c9103"}, {"url": "https://git.kernel.org/stable/c/038166f873c4caf6e85cfd4ea0c5a5ba297b4e8b"}, {"url": "https://git.kernel.org/stable/c/649932fc3815eda2f24eb4de4b3a5e94886ee0b9"}], "title": "erofs: fix managed cache race for unaligned extents", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/erofs/zdata.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "2718cdb6db0fdbe375e61f2980aada27bafb323e", "status": "affected", "version": "722f0fcdb0bb7d12a5c6d9460b9a7de1f735f36d", "versionType": "git"}, {"lessThan": "425d32d6288d7d845e486af9419bbedccd8c9103", "status": "affected", "version": "7361d1e3763baaf7b9349c576137851458ad38d1", "versionType": "git"}, {"lessThan": "038166f873c4caf6e85cfd4ea0c5a5ba297b4e8b", "status": "affected", "version": "7361d1e3763baaf7b9349c576137851458ad38d1", "versionType": "git"}, {"lessThan": "649932fc3815eda2f24eb4de4b3a5e94886ee0b9", "status": "affected", "version": "7361d1e3763baaf7b9349c576137851458ad38d1", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/erofs/zdata.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.15"}, {"lessThan": "6.15", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.34", "versionType": "semver"}, {"lessThanOrEqual": "7.0.*", "status": "unaffected", "version": "7.0.11", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.1", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "89E9B97C-FD82-4D2E-8426-3A1A703B2ED7", "versionEndExcluding": "6.18.34", "versionStartIncluding": "6.15", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "0520D091-FC52-4A50-AF07-70AE7D08B750", "versionEndExcluding": "7.0.11", "versionStartIncluding": "6.19", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*", "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*", "matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*", "matchCriteriaId": "EC732D08-5F7B-46D9-B154-E60C7F4F0A97", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*", "matchCriteriaId": "E5910A9D-F60A-409A-B486-FE66BFEBA9B9", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nerofs: fix managed cache race for unaligned extents\n\nAfter unaligned compressed extents were introduced, the following race\ncould occur:\n\n[Thread 1] [Thread 2]\n(z_erofs_fill_bio_vec)\n<handle a Z_EROFS_PREALLOCATED_FOLIO folio>\n...\nfilemap_add_folio (1)\n (z_erofs_bind_cache)\n <the same folio is found..>\n ..\n ..\nfolio_attach_private (2)\n filemap_add_folio (3) again\n\nSince (1) is executed but (2) hasn't been executed yet, it's possible\nthat another thread finds the same managed folio in z_erofs_bind_cache()\nfor a different pcluster and calls filemap_add_folio() again since\nfolio->private is still Z_EROFS_PREALLOCATED_FOLIO.\n\nFix this by explicitly clearing folio->private before making the folio\nvisible in the managed cache so that another pcluster can simply wait\non the locked managed folio as what we did for other shared cases [1].\n\nThis only impacts unaligned data compression (`-E48bit` with zstd,\nfor example).\n\n[1] Commit 9e2f9d34dd12 (\"erofs: handle overlapped pclusters out of\n crafted images properly\") was originally introduced to handle crafted\n overlapped extents, but it addresses unaligned extents as well."}], "id": "CVE-2026-64031", "lastModified": "2026-10-13T15:32:44.990", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-07-19T16:17:43.250", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/038166f873c4caf6e85cfd4ea0c5a5ba297b4e8b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/2718cdb6db0fdbe375e61f2980aada27bafb323e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/425d32d6288d7d845e486af9419bbedccd8c9103"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/649932fc3815eda2f24eb4de4b3a5e94886ee0b9"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-362"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: erofs: fix managed cache race for unaligned extents", "id": "2502425", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2502425"}, "csaw": false, "cwe": "CWE-367", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nerofs: fix managed cache race for unaligned extents\nAfter unaligned compressed extents were introduced, the following race\ncould occur:\n[Thread 1] [Thread 2]\n(z_erofs_fill_bio_vec)\n<handle a Z_EROFS_PREALLOCATED_FOLIO folio>\n...\nfilemap_add_folio (1)\n(z_erofs_bind_cache)\n<the same folio is found..>\n..\n..\nfolio_attach_private (2)\nfilemap_add_folio (3) again\nSince (1) is executed but (2) hasn't been executed yet, it's possible\nthat another thread finds the same managed folio in z_erofs_bind_cache()\nfor a different pcluster and calls filemap_add_folio() again since\nfolio->private is still Z_EROFS_PREALLOCATED_FOLIO.\nFix this by explicitly clearing folio->private before making the folio\nvisible in the managed cache so that another pcluster can simply wait\non the locked managed folio as what we did for other shared cases [1].\nThis only impacts unaligned data compression (`-E48bit` with zstd,\nfor example).\n[1] Commit 9e2f9d34dd12 (\"erofs: handle overlapped pclusters out of\ncrafted images properly\") was originally introduced to handle crafted\noverlapped extents, but it addresses unaligned extents as well.", "A flaw was found in the Linux kernel's `erofs` filesystem. A race condition exists when processing unaligned compressed extents, which can cause a managed memory page (folio) to be incorrectly added to the page cache multiple times. This inconsistency in memory management could allow a local attacker to trigger a system crash, leading to a denial of service (DoS)."], "name": "CVE-2026-64031", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-07-19T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-64031\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-64031\nhttps://lore.kernel.org/linux-cve-announce/2026071904-CVE-2026-64031-b0e9@gregkh/T"]}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[7361d1e3763baaf7b9349c576137851458ad38d1,425d32d6288d7d845e486af9419bbedccd8c9103)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[7361d1e3763baaf7b9349c576137851458ad38d1,038166f873c4caf6e85cfd4ea0c5a5ba297b4e8b)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[7361d1e3763baaf7b9349c576137851458ad38d1,649932fc3815eda2f24eb4de4b3a5e94886ee0b9)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "6.15"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.15)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.34,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.0.11,7.1.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-07-21T07:45:03.516859+00:00", "updated": "2026-10-17T10:30:07.233319+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}