{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-21832", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-29T08:45:45.777Z", "datePublished": "2025-03-06T16:22:34.125Z", "dateUpdated": "2026-08-05T11:54:48.618Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:54:48.618Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nblock: don't revert iter for -EIOCBQUEUED\n\nblkdev_read_iter() has a few odd checks, like gating the position and\ncount adjustment on whether or not the result is bigger-than-or-equal to\nzero (where bigger than makes more sense), and not checking the return\nvalue of blkdev_direct_IO() before doing an iov_iter_revert(). The\nlatter can lead to attempting to revert with a negative value, which\nwhen passed to iov_iter_revert() as an unsigned value will lead to\nthrowing a WARN_ON() because unroll is bigger than MAX_RW_COUNT.\n\nBe sane and don't revert for -EIOCBQUEUED, like what is done in other\nspots." } ], "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 through local syscalls only — io_uring submission (or aio) of an O_DIRECT read against a block device file descriptor. There is no network-facing path into `blkdev_read_iter()`.\nAC:L - The attacker controls both sides of the race: setting `IOSQE_ASYNC` forces io-wq offload so the completion runs in parallel with the still-executing `blkdev_read_iter()`, and choosing a fast backing device (NVMe/brd/null_blk/loop) plus unbounded submission retries makes the window trivially winnable.\nPR:L - Only an unprivileged local account is needed, holding a readable block device node opened with O_DIRECT — commonly available via the disk/cdrom groups, udev uaccess on removable media, containers with device access, and embedded/automotive/IoT images where the application user has raw device access. No CAP_SYS_ADMIN or root is required.\nUI:N - The attacker submits the io_uring read entirely on their own; no victim action, mount, or file open by another user is involved.\nS:U - The freed object, the corruption, and the resulting impact are all within the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - This is a use-after-free — `iov_iter_count()`/`iov_iter_revert()` read the recycled `io_async_rw` and walk backwards out of bounds through a freed or reused bvec/iovec array, and the resulting corrupted iter can be consumed by another in-flight request to DMA arbitrary kernel memory back to the attacker.\nI:H - `iov_iter_revert()` writes `count`, `iov_offset`, `nr_segs`, and the `bvec`/`__iov` pointer into freed/recycled heap memory with an attacker-influenced `unroll`, giving heap-spray-able corruption of a concurrently used iterator that is exploitable for out-of-bounds writes and control-flow hijacking.\nA:H - The reported symptom is a `WARN_ON()` in `iov_iter_revert()` (immediate panic under panic_on_warn), and for the common `ITER_UBUF`/xarray iters the same path hits an unconditional `BUG()`; the underlying use-after-free also crashes the kernel outright under KASAN or on heap corruption." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "block/fops.c" ], "versions": [ { "version": "3e1f941dd9f33776b3df4e30f741fe445ff773f3", "lessThan": "6c26619effb1b4cb7d20b4e666ab8f71f6a53ccb", "status": "affected", "versionType": "git" }, { "version": "3e1f941dd9f33776b3df4e30f741fe445ff773f3", "lessThan": "84671b0630ccb46ae9f1f99a45c7d63ffcd6a474", "status": "affected", "versionType": "git" }, { "version": "3e1f941dd9f33776b3df4e30f741fe445ff773f3", "lessThan": "68f16d3034a06661245ecd22f0d586a8b4e7c473", "status": "affected", "versionType": "git" }, { "version": "3e1f941dd9f33776b3df4e30f741fe445ff773f3", "lessThan": "a58f136bad29f9ae721a29d98c042fddbee22f77", "status": "affected", "versionType": "git" }, { "version": "3e1f941dd9f33776b3df4e30f741fe445ff773f3", "lessThan": "b13ee668e8280ca5b07f8ce2846b9957a8a10853", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "block/fops.c" ], "versions": [ { "version": "5.17", "status": "affected" }, { "version": "0", "lessThan": "5.17", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.129", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.78", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.14", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13.3", "lessThanOrEqual": "6.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14", "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": "5.17", "versionEndExcluding": "6.1.129" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17", "versionEndExcluding": "6.6.78" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17", "versionEndExcluding": "6.12.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17", "versionEndExcluding": "6.13.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17", "versionEndExcluding": "6.14" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/6c26619effb1b4cb7d20b4e666ab8f71f6a53ccb" }, { "url": "https://git.kernel.org/stable/c/84671b0630ccb46ae9f1f99a45c7d63ffcd6a474" }, { "url": "https://git.kernel.org/stable/c/68f16d3034a06661245ecd22f0d586a8b4e7c473" }, { "url": "https://git.kernel.org/stable/c/a58f136bad29f9ae721a29d98c042fddbee22f77" }, { "url": "https://git.kernel.org/stable/c/b13ee668e8280ca5b07f8ce2846b9957a8a10853" } ], "title": "block: don't revert iter for -EIOCBQUEUED", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T21:00:04.401Z" } } ] } }