# CVE-2026-89578: linux: In the Linux kernel, the following vulnerability has been resolved:  dm-io: clone the source bio instead of copying i...

CVE-2026-89578 is fixed in 20 products on 1 platform, first by DEBIAN-CVE-2026-89578, released September 23, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-89578
- Priority: High
- CVSS: n/a (important)
- EPSS: 0.0020
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 11, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:  dm-io: clone the source bio instead of copying its biovec  For DM_IO_BIO requests, do_region() built each destination bio by walking the source bio's biovec and re-adding the pages one at a time, tracking the remaining transfer in sectors. The vector lengths are byte granular and need not be sector aligned (e.g. a misaligned O_DIRECT buffer split across pages), so the sector-based accounting could lose a sub-sector fragment: to_sector() truncated the remainder and the outer loop spun forever submitting empty bios, hanging the I/O.  There is no need to rebuild the biovec at all. The destination reads into (or writes from) exactly the same pages as the source bio, so the bio can simply clone the source's biovec with bio_alloc_clone() and remap it to the target device. The clone inherits the source's iterator and alignment, and the block layer splits it to the target's limits on submission, so the whole region maps to a single cloned bio with no manual page copying or sector accounting.  This removes the per-page copy path (and its open-coded bvec dpages helpers) for bio-backed I/O and fixes the hang on misaligned direct I/O to a dm-mirror device. Page-list, vma and kmem sources keep the existing copy path.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | bpftool6.18 amzn 2023 | 1:6.18.51-120.162.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |
| Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.51-120.162.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |
| Linux | kernel-livepatch-6.18.51-120.162 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |
| Linux | kernel6.18 amzn 2023 | 1:6.18.51-120.162.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |
| Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.51-120.162.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |
| Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.51-120.162.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |
| Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.51-120.162.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |
| Linux | kernel6.18-devel amzn 2023 | 1:6.18.51-120.162.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |
| Linux | kernel6.18-headers amzn 2023 | 1:6.18.51-120.162.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |
| Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.51-120.162.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |
| Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.51-120.162.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |
| Linux | kernel6.18-tools amzn 2023 | 1:6.18.51-120.162.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |
| Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.51-120.162.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |
| Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.51-120.162.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |
| Linux | linux Debian 14 | 7.2.6-1 | [DEBIAN-CVE-2026-89578](https://patchblox.com/security/data/fix/linux/debian-cve-2026-89578.md) | Sep 23, 2026 |
| Linux | microvm-kernel6.18 amzn 2023 | 1:6.18.51-120.162.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |
| Linux | perf6.18 amzn 2023 | 1:6.18.51-120.162.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |
| Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.51-120.162.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |
| Linux | python3-perf6.18 amzn 2023 | 1:6.18.51-120.162.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |
| Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.51-120.162.amzn2023 | [ALAS2023-2026-3187](https://patchblox.com/security/data/fix/linux/alas2023-2026-3187.md) | Nov 7, 2026 |

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Data as of 2026-11-09T07:25:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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