{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-54285", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-12-30T12:06:44.526Z", "datePublished": "2025-12-30T12:23:25.770Z", "dateUpdated": "2026-08-05T09:18:57.424Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T09:18:57.424Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niomap: Fix possible overflow condition in iomap_write_delalloc_scan\n\nfolio_next_index() returns an unsigned long value which left shifted\nby PAGE_SHIFT could possibly cause an overflow on 32-bit system. Instead\nuse folio_pos(folio) + folio_size(folio), which does this correctly." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H", "baseScore": 7.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The flaw is reached through a local `write()`/`pwrite()` syscall on a buffered file on an iomap/XFS filesystem, via `iomap_file_buffered_write()` → `xfs_buffered_write_iomap_end()` → `iomap_write_delalloc_release()`. No network-facing service reliably produces the required short-write-with-partial-copy condition, so local access is needed.\nAC:L - The attacker deterministically controls every trigger condition: creating a file larger than 4 GiB, dirtying folios above that offset, and forcing a short write by passing a buffer that straddles an unmapped/PROT_NONE page so `fault_in_iov_iter_readable()` fails. On the affected deployment class (32-bit ARM/x86 embedded, industrial and NAS devices running XFS) the 32-bit truncation is a fixed property of the target, not a race or a condition outside attacker control.\nPR:L - Only an unprivileged local account with write access to any file on an XFS filesystem (e.g. /tmp, /var, or a home directory) is required. No capability, root, or namespace trickery is needed anywhere along the `vfs_write` → iomap path.\nUI:N - The attacker performs the entire sequence — extending the file past 4 GiB, dirtying page cache, issuing the faulting write — in its own process. No victim action or cooperation is required.\nS:U - The overflow and its effects are confined to the kernel's own filesystem/page-cache state on the same system; no VM, IOMMU, or sandbox security boundary is crossed.\nC:N - The miscalculation only causes delalloc (unwritten reservation) extents to be removed; `xfs_bmap_punch_delalloc_range()` explicitly skips real allocated extents via the `isnullstartblock()` check, so no out-of-bounds read occurs and punched ranges read back as zeroes rather than exposing stale disk or kernel memory.\nI:H - The wrapped `punch_start_byte` causes delalloc reservations to be punched over a range up to ~4 GiB below the intended one, leaving dirty page-cache data with no backing reservation; `xfs_map_blocks()` then finds a hole at writeback and the data is silently discarded, permanently destroying file contents — including data written concurrently by other users to a shared file — and leaving the on-disk extent state inconsistent with the page cache.\nA:H - The corrupted punch range trips `WARN_ON_ONCE(start_byte < punch_start_byte)` (a panic under `panic_on_warn`) and drives writeback into holes, producing XFS writeback errors and filesystem shutdown that renders the volume unusable; on affected kernels the same 32-bit truncation in the adjacent loop-advance expression additionally yields an unkillable infinite loop while holding `i_rwsem` and the mapping invalidate lock, permanently wedging the inode and burning a CPU." } ] } ], "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": "38be53c3fd7f4f4bd5de319a323d72f9f6beb16d", "lessThan": "0c6cf409093f307ee05114f834516730c0da5b21", "status": "affected", "versionType": "git" }, { "version": "f43dc4dc3eff028b5ddddd99f3a66c5a6bdd4e78", "lessThan": "5c281b0c5d18c8eeb1cfd5023f4adb153e6d1240", "status": "affected", "versionType": "git" }, { "version": "f43dc4dc3eff028b5ddddd99f3a66c5a6bdd4e78", "lessThan": "eee2d2e6ea5550118170dbd5bb1316ceb38455fb", "status": "affected", "versionType": "git" }, { "version": "6.1.92", "lessThan": "6.1.162", "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/iomap/buffered-io.c" ], "versions": [ { "version": "6.2", "status": "affected" }, { "version": "0", "lessThan": "6.2", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.162", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.5.5", "lessThanOrEqual": "6.5.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6", "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": "6.1.92", "versionEndExcluding": "6.1.162" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.5.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/0c6cf409093f307ee05114f834516730c0da5b21" }, { "url": "https://git.kernel.org/stable/c/5c281b0c5d18c8eeb1cfd5023f4adb153e6d1240" }, { "url": "https://git.kernel.org/stable/c/eee2d2e6ea5550118170dbd5bb1316ceb38455fb" } ], "title": "iomap: Fix possible overflow condition in iomap_write_delalloc_scan", "x_generator": { "engine": "bippy-1.2.0" } } } }