CVE-2026-64031

erofs: fix managed cache race for unaligned extents

CVSS 3.1 7.8 HIGHCheck source for fixed versionsKEV status unknown

Original advisory

cve-program · CVE-2026-64031

Published

In the Linux kernel, the following vulnerability has been resolved: erofs: fix managed cache race for unaligned extents After unaligned compressed extents were introduced, the following race could occur: [Thread 1] [Thread 2] (z_erofs_fill_bio_vec) <handle a Z_EROFS_PREALLOCATED_FOLIO folio> ... filemap_add_folio (1) (z_erofs_bind_cache) <the same folio is found..> .. .. folio_attach_private (2) filemap_add_folio (3) again Since (1) is executed but (2) hasn't been executed yet, it's possible that another thread finds the same managed folio in z_erofs_bind_cache() for a different pcluster and calls filemap_add_folio() again since folio->private is still Z_EROFS_PREALLOCATED_FOLIO. Fix this by explicitly clearing folio->private before making the folio visible in the managed cache so that another pcluster can simply wait on the locked managed folio as what we did for other shared cases [1]. This only impacts unaligned data compression (`-E48bit` with zstd, for example). [1] Commit 9e2f9d34dd12 ("erofs: handle overlapped pclusters out of crafted images properly") was originally introduced to handle crafted overlapped extents, but it addresses unaligned extents as well.

Read the publisher's advisory

Affected versions, risk and source history

cve-program · CVE-2026-64031

Published

Linux

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "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"
                        }
                    ]
                }

Linux

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "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"
                        }
                    ]
                }

Original source record · Cite this exact observation · Complete original publisher JSON