{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-90199","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-11T19:38:34.792Z","datePublished":"2026-09-17T16:07:17.550Z","dateUpdated":"2026-09-18T17:53:40.108Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-18T17:53:40.108Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: reject out-of-range evcn in mi_enum_attr()\n\nIn mi_enum_attr(), the start/end VCN validation for non-resident\nattributes is:\n\n\tif (svcn > evcn + 1) goto out;\n\nWhen evcn is U64_MAX the \"evcn + 1\" expression wraps to 0 and any svcn\npasses the check. For evcn values close to U64_MAX (but not equal to it)\nthe right-hand side is still a meaningless near-wrap upper bound, so a\nmalformed on-disk attribute with svcn == 0 and evcn near U64_MAX can pass\nmi_enum_attr() unrejected.\n\nVCN (virtual cluster number) is a cluster index, so any valid evcn is\nbounded by the volume's total cluster count, which ntfs3 holds in\nsbi->used.bitmap.nbits (set up in ntfs_init_from_boot() before any caller\nof mi_enum_attr() runs). Reject evcn values that fall outside this range.\n\nHowever, an empty non-resident attribute (no allocated clusters) is\nlegitimately encoded with svcn == 0 and evcn == -1 (U64_MAX), e.g. via\nattr->nres.evcn = cpu_to_le64((u64)vcn - 1) with vcn == 0. That sentinel\nmust keep passing, so exclude evcn == U64_MAX from the range check. The\nexisting \"svcn > evcn + 1\" test still tolerates the sentinel (\"0 > 0\" is\nfalse) and continues to require svcn == 0 for it, while the range check\nrejects every other out-of-range evcn and thereby also defuses the\n\"evcn + 1\" wraparound.\n\nsvcn does not need its own bound: once evcn < nbits, \"svcn > evcn + 1\"\nimplies svcn <= nbits.\n\n[almaz.alexandrovich@paragon-software.com: fixed evcn check]"}],"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 malformed field is attr->nres.evcn (with svcn) in a non-resident MFT attribute on the block device. It is parsed by mount(2) → ntfs_fill_super() → ntfs_iget5() → ntfs_read_mft() → ni_enum_attr_ex() → mi_enum_attr(); no network protocol carries those VCN fields.\nAC:L - The attacker sets on-disk evcn ≥ sbi->used.bitmap.nbits or near U64_MAX with svcn==0 so mi_enum_attr()'s u64 test `svcn > evcn + 1` never fails (evcn+1 wraps only at U64_MAX). A single sparse mapping pair of length evcn+1 then makes run_unpack() succeed; there is no race.\nPR:N - Crafting the NTFS image requires no account on the target. ntfs_fs_type has no FS_USERNS_MOUNT, so the CAP_SYS_ADMIN mount is the victim's action and is counted as UI:R rather than attacker privilege.\nUI:R - A victim must mount the attacker-supplied NTFS volume so ntfs_fill_super()/ntfs_read_mft() will run mi_enum_attr() on the crafted evcn; that mount is the required user action.\nS:U - Corruption stays in the host kernel's ntfs3 runs_tree and MFT record buffers; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - Accepted evcn near U32_MAX is passed to run_unpack_ex() and installed as a sparse run of length ~U32_MAX. A later write hits run_add_entry(), which splits that run with wrapping CLST adds (r->vcn+r->len, tail_len=r->len-Tovcn), so lookups return wrong LCNs and can read past the kvmalloc'd runs array.\nI:H - The same wrapping split does `r->len += len - ((r->vcn + r->len) - vcn)` and run_consolidate() joins on wrapped end points; mi_pack_runs() then writes the corrupted mapping pairs into the kmalloc'd MFT record — a kernel-heap write of attacker-influenced run metadata.\nA:H - Walking off the runs array on the wrapped split, or submitting an iomap bio from a wrapped LCN in ntfs_iomap_begin() after attr_data_get_block(), oopses the kernel; attr_set_size_ex() also takes _ntfs_bad_inode() on the inconsistent vcn/evcn state."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ntfs3/record.c"],"versions":[{"version":"013ff63b649475f0ee134e2c8d0c8e65284ede50","lessThan":"0441e34ce098c19185a7b52c5b8b89a8a5b26888","status":"affected","versionType":"git"},{"version":"013ff63b649475f0ee134e2c8d0c8e65284ede50","lessThan":"7ab69cef49ebdfee288287d62641b24ab1445ecc","status":"affected","versionType":"git"},{"version":"013ff63b649475f0ee134e2c8d0c8e65284ede50","lessThan":"ce9a619c432b9a4044fee115c5483fbed946c131","status":"affected","versionType":"git"},{"version":"013ff63b649475f0ee134e2c8d0c8e65284ede50","lessThan":"2b9a0e57bfd365e2096706b19ae34dce3b4a884b","status":"affected","versionType":"git"},{"version":"013ff63b649475f0ee134e2c8d0c8e65284ede50","lessThan":"20fd9f64c0050658f2031e6bd5d552c6f0c8f7e3","status":"affected","versionType":"git"},{"version":"a7accf181a4709a6e380360372150cc4a1b6b89a","status":"affected","versionType":"git"},{"version":"3dfd727873c3e8da74a2e3907120ff052c5f0bcc","status":"affected","versionType":"git"},{"version":"1d7dd485108d4f633b543c9c14071cc325b68ae5","status":"affected","versionType":"git"},{"version":"5.15.209","lessThan":"5.16","status":"affected","versionType":"semver"},{"version":"6.1.115","lessThan":"6.2","status":"affected","versionType":"semver"},{"version":"6.5.11","lessThan":"6.6","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ntfs3/record.c"],"versions":[{"version":"6.6","status":"affected"},{"version":"0","lessThan":"6.6","status":"unaffected","versionType":"semver"},{"version":"6.6.157","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.110","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.52","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.6","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc1","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":"6.6","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"6.12.110"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"6.18.52"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"7.2.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"7.3-rc1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.115"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5.11"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/0441e34ce098c19185a7b52c5b8b89a8a5b26888"},{"url":"https://git.kernel.org/stable/c/7ab69cef49ebdfee288287d62641b24ab1445ecc"},{"url":"https://git.kernel.org/stable/c/ce9a619c432b9a4044fee115c5483fbed946c131"},{"url":"https://git.kernel.org/stable/c/2b9a0e57bfd365e2096706b19ae34dce3b4a884b"},{"url":"https://git.kernel.org/stable/c/20fd9f64c0050658f2031e6bd5d552c6f0c8f7e3"}],"title":"fs/ntfs3: reject out-of-range evcn in mi_enum_attr()","x_generator":{"engine":"bippy-1.2.0"}}}}