{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90133", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.788Z", "datePublished": "2026-09-17T16:06:33.234Z", "dateUpdated": "2026-10-19T08:58:31.458Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:58:31.458Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: Fix index_root heap OOB write in ntfs_ir_to_ib()\n\nntfs_ir_to_ib copies all entries from index_root into a freshly allocated\nindex_block_size-byte buffer without verifying that the entries fit in the\navailable space. The entries in index_root may be larger than the usable\nentry space in the index block.\n\nThis can cause OOB writes past the end of the allocation.\n\nThe validator ntfs_index_root_inconsistent() checks that entries are\nself-consistent within the IR value, but never cross-checks them against\nindex_block_size. There is no bounds check in ntfs_ir_to_ib() before the\nmemcpy.\n\nFixing this at the sink in ntfs_ir_to_ib() since\nntfs_index_root_inconsistent() validates the logical consistency of\nindex_root as a structure and a root with large entries is a structurally\nvalid root. The bug is a size conflict of ntfs_ir_to_ib().\nAlso, the validator is called once per inode load in\nntfs_read_locked_inode() while ntfs_ir_to_ib() is only called during a\nreparent, a check there adds no overhead to the common path.\nMoreover, even a future call path that bypasses the validator would still\nbe protected.\n\nWith NULL as first parameter of ntfs_error(), the volume error flag is\nnever set by this call, so the device name will be absent from the error\nmessage. In any case, that the caller, ntfs_ir_reparent(), prints an error\nmessage that includes the device name on NULL returns.\nI think this is the best solution available without adding\n'struct super_block *sb' as a parameter to ntfs_ir_to_ib().\n\nThis heap out-of-bounds write is triggered by a crafted filesystem image,\nwhich is not in the kernel threat model, anyway, fixing memory errors would\nbe nice to keep things secure." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The overflow source is on-disk $INDEX_ROOT (ir->index_block_size and the resident entries) that ntfs_ir_to_ib() memcpy()s; the trigger is vfs_create/mkdir/link/rename → ntfs_create/__ntfs_link → ntfs_index_add_filename → ntfs_ie_add → ntfs_ir_make_space → ntfs_ir_reparent. No protocol message carries those fields.\nAC:L - ntfs_read_locked_inode() accepts any power-of-two index_block_size in [512, PAGE_SIZE] and ntfs_index_root_inconsistent() never compares entry bytes to that size, so a 512-byte IB plus a packed resident INDEX_ROOT in a full MFT record makes ntfs_ir_truncate() return -ENOSPC and ntfs_ir_reparent() run on the next create, with no race.\nPR:N - mount_capable() needs init-namespace CAP_SYS_ADMIN because ntfs_fs_type lacks FS_USERNS_MOUNT; that mount is the victim or udisks2/vold action (UI:R), not attacker privilege. After mount, ntfs_create() is an ordinary VFS create on a directory whose mode the image controls, so the attacker needs no account.\nUI:R - ntfs_ir_to_ib() is called only from ntfs_ir_reparent(), not from ntfs_fill_super(), so attaching the volume is not enough. A victim or automounter must mount the attacker-supplied NTFS image, and then create/mkdir/link/rename must add a filename so ntfs_ie_add() takes the ENOSPC reparent path.\nS:U - The kvzalloc(index_block) overflow in ntfs_ir_to_ib() corrupts host-kernel heap in the same OS authority as fs/ntfs; it is in-kernel memory corruption, not a VM escape, IOMMU bypass, or sandbox breakout.\nC:H - memcpy() in ntfs_ir_to_ib() writes attacker-controlled INDEX_ROOT entry bytes (UTF-16 names, MFT refs) past the kvzalloc(ir->index_block_size) object into adjacent slab, a heap OOB write that can be groomed to disclose neighboring kernel objects.\nI:H - The same memcpy is an unbounded heap out-of-bounds write of attacker-chosen index-entry contents past the allocated index_block, which can corrupt adjacent slab objects and hijack kernel control flow.\nA:H - Writing past the kvzalloc index_block into unmapped or poisoned adjacent heap oopses or panics on the ntfs_ir_reparent() create/mkdir path, fully denying availability even when the overflow is not turned into a write primitive." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ntfs/index.c" ], "versions": [ { "version": "0a8ac0c1fa0b99a5b29002bc7f232ed7eafddef0", "lessThan": "825dec5120933e90c54e30e31ccfa6c3449043a8", "status": "affected", "versionType": "git" }, { "version": "0a8ac0c1fa0b99a5b29002bc7f232ed7eafddef0", "lessThan": "dc09bf79b76f9a7157e225f449655f3f62f96c9c", "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/index.c" ], "versions": [ { "version": "7.1", "status": "affected" }, { "version": "0", "lessThan": "7.1", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.6", "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": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.1", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/825dec5120933e90c54e30e31ccfa6c3449043a8" }, { "url": "https://git.kernel.org/stable/c/dc09bf79b76f9a7157e225f449655f3f62f96c9c" } ], "title": "ntfs: Fix index_root heap OOB write in ntfs_ir_to_ib()", "x_generator": { "engine": "bippy-1.2.0" } } } }