{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-68145", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.371Z", "datePublished": "2026-08-10T11:59:09.721Z", "dateUpdated": "2026-08-23T12:45:56.875Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-23T12:45:56.875Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niomap: fix out-of-bounds bitmap_set() with zero-length range\n\nifs_set_range_dirty() and ifs_set_range_uptodate() compute last_blk\nas (off + len - 1) >> i_blkbits. When off is 0 and len is 0, the\nunsigned subtraction underflows to SIZE_MAX, producing a huge\nlast_blk and nr_blks value that causes bitmap_set() to write far\nbeyond the ifs->state allocation.\n\nRegarding ifs_set_range_uptodate(), it is temporarily safe because len\ncannot be passed in as 0. However, for ifs_set_range_dirty() this is\nreachable from __iomap_write_end(): when copy_folio_from_iter_atomic()\nreturns 0 (e.g. user buffer fault) and the folio is already uptodate,\nthe guard at the top of __iomap_write_end() does not trigger because\n!folio_test_uptodate() is false, and iomap_set_range_dirty() is called\nwith copied == 0.\n\nAdd a !len guard to both functions before the computation, so that a\nzero-length range is a no-op." } ], "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 via the buffered write() path through iomap_file_buffered_write() when copy_folio_from_iter_atomic() returns 0; NFS/ksmbd server writes use kernel bvec iterators and do not hit this user-buffer fault path.\nAC:L - An attacker can reliably trigger copied==0 by racing munmap/remap against write() on an already-uptodate folio (TOCTOU after fault_in_iov_iter_readable), controlling both sides of the race on systems where folio size exceeds filesystem block size.\nPR:L - Only standard local write permission to a file on an iomap-backed filesystem (XFS, GFS2, FUSE writeback-cache, zonefs, NTFS) is required; no CAP_SYS_ADMIN or other elevated capability is needed beyond creating/triggering writes to attacker-writable files.\nUI:N - Exploitation requires only the attacker's own write operations to a writable file; no action by another user or administrator (such as mounting a filesystem or opening a file on the victim's behalf) is needed.\nS:U - Successful exploitation corrupts host kernel heap memory and enables local privilege escalation within the same kernel security domain; it does not inherently cross VM, container, or IOMMU boundaries.\nC:H - ifs_set_range_dirty() with len==0 underflows to SIZE_MAX and bitmap_set() writes far beyond the small kzalloc_flex(ifs->state) allocation, corrupting adjacent kmalloc objects in ways that can be leveraged for arbitrary kernel memory disclosure.\nI:H - The out-of-bounds bitmap_set() is a large heap overwrite primitive adjacent to the iomap_folio_state allocation, enabling control of kernel data structures and arbitrary code execution via standard heap exploitation techniques.\nA:H - The massive out-of-bounds write can immediately corrupt critical kernel heap metadata or adjacent objects, causing kernel oops/panic or unrecoverable memory corruption even before full exploitation is attempted." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/iomap/buffered-io.c" ], "versions": [ { "version": "4ce02c67972211be488408c275c8fbf19faf29b3", "lessThan": "48829622212f6b8f49155889aecc818ba28ba680", "status": "affected", "versionType": "git" }, { "version": "4ce02c67972211be488408c275c8fbf19faf29b3", "lessThan": "fb4fad9105c88b1d82f1b3c39e3b6abea8249af6", "status": "affected", "versionType": "git" }, { "version": "4ce02c67972211be488408c275c8fbf19faf29b3", "lessThan": "7037e7bdcd26f46c080b8ce307dee5cb471c4b7c", "status": "affected", "versionType": "git" }, { "version": "4ce02c67972211be488408c275c8fbf19faf29b3", "lessThan": "c5b6a48a8a716a7730e39af1cad083dc4ec955ce", "status": "affected", "versionType": "git" }, { "version": "4ce02c67972211be488408c275c8fbf19faf29b3", "lessThan": "9c7d8f7c8994c790fca501dc45ce66e7356cbe05", "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/iomap/buffered-io.c" ], "versions": [ { "version": "6.6", "status": "affected" }, { "version": "0", "lessThan": "6.6", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.153", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.101", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.6", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "6.6.153" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "6.12.101" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "6.18.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "7.1.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/48829622212f6b8f49155889aecc818ba28ba680" }, { "url": "https://git.kernel.org/stable/c/fb4fad9105c88b1d82f1b3c39e3b6abea8249af6" }, { "url": "https://git.kernel.org/stable/c/7037e7bdcd26f46c080b8ce307dee5cb471c4b7c" }, { "url": "https://git.kernel.org/stable/c/c5b6a48a8a716a7730e39af1cad083dc4ec955ce" }, { "url": "https://git.kernel.org/stable/c/9c7d8f7c8994c790fca501dc45ce66e7356cbe05" } ], "title": "iomap: fix out-of-bounds bitmap_set() with zero-length range", "x_generator": { "engine": "bippy-1.2.0" } } } }