{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-98315", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.339Z", "datePublished": "2026-10-06T08:46:10.751Z", "dateUpdated": "2026-10-19T09:17:25.955Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:17:25.955Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: protect runlist updates with the runlist lock\n\nntfs_non_resident_attr_shrink() calls runlist helpers that require the\nrunlist write lock, but did not hold it while freeing clusters and\ntruncating the runlist. Serialize those operations and the resident\nconversion with the runlist lock.\n\nntfs_attr_map_cluster() can merge a newly allocated run before updating\nmapping pairs. If the update fails, free the clusters and restore both\nthe in-memory runlist and on-disk mapping pairs from a saved runlist.\nMark the volume in error if either rollback step fails." } ], "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 trigger is a local ftruncate() on a file in a mounted NTFS volume, via ntfs_setattr_size()->ntfs_truncate_vfs()->__ntfs_attr_truncate_vfs()->ntfs_non_resident_attr_shrink(). That path frees clusters and calls ntfs_rl_truncate_nolock() without ni->runlist.lock. No remote protocol supplies the input; it is a locking defect on a well-formed volume.\nAC:L - The attacker runs both sides of the race: one thread dirties and fsync()s the file, driving ntfs_writeback_range()->__ntfs_write_iomap_begin(), which walks and merges ni->runlist.rl under runlist.lock. Another thread repeatedly ftruncate()s the same file, reallocating or kvfree()ing rl without that lock. It can be retried at will.\nPR:L - The attacker only needs an ordinary local account with write permission on a file in an already-mounted NTFS volume, as needed for setattr ATTR_SIZE and writeback. No capability is checked on this path.\nUI:N - No crafted image or victim mount is needed. The race works against any legitimately mounted NTFS volume, using only the attacker's own truncate and write/fsync calls on a file the attacker can already write.\nS:U - The memory corruption stays within the kernel's own security authority. No guest/host, IOMMU or sandbox boundary is crossed.\nC:H - ntfs_rl_truncate_nolock() reallocates or frees the kvmalloc'd runlist array while writeback still holds a pointer into it, so the freed slab can be reclaimed and its contents read back as cluster mappings (LCNs). That can direct I/O at arbitrary disk clusters, and is a use-after-free read of kernel memory.\nI:H - The writeback path merges new runs into the freed or reallocated runlist array (heap use-after-free write). Concurrently, ntfs_cluster_free() and the shrink update the shared runlist and on-disk mapping pairs without serialization, corrupting both kernel heap memory and filesystem metadata.\nA:H - Losing the race leads to a KASAN use-after-free or oops in the runlist walk, a double kvfree, or a corrupted runlist and mapping pairs that leave the volume inconsistent and can crash later lookups." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ntfs/attrib.c", "fs/ntfs/attrib.h", "fs/ntfs/attrlist.c", "fs/ntfs/attrlist.h", "fs/ntfs/compress.c", "fs/ntfs/file.c", "fs/ntfs/inode.c", "fs/ntfs/mft.c" ], "versions": [ { "version": "495e90fa334828d4119061e2726af51d0a0fb4ed", "lessThan": "742797432e8c9b0dd54ecc523c185e26b09d79a0", "status": "affected", "versionType": "git" }, { "version": "495e90fa334828d4119061e2726af51d0a0fb4ed", "lessThan": "91709ba5d6d709b2b663287b7e871e2c6b480502", "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/ntfs/attrib.c", "fs/ntfs/attrib.h", "fs/ntfs/attrlist.c", "fs/ntfs/attrlist.h", "fs/ntfs/compress.c", "fs/ntfs/file.c", "fs/ntfs/inode.c", "fs/ntfs/mft.c" ], "versions": [ { "version": "7.1", "status": "affected" }, { "version": "0", "lessThan": "7.1", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.8", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "7.1", "versionEndExcluding": "7.2.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.1", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/742797432e8c9b0dd54ecc523c185e26b09d79a0" }, { "url": "https://git.kernel.org/stable/c/91709ba5d6d709b2b663287b7e871e2c6b480502" } ], "title": "ntfs: protect runlist updates with the runlist lock", "x_generator": { "engine": "bippy-1.2.0" } } } }