# CVE-2026-100073: linux: In the Linux kernel, the following vulnerability has been resolved:  ext4: fix transaction overflow during writeback...

CVE-2026-100073 is fixed in linux on 1 platform by DEBIAN-CVE-2026-100073 (version 7.2.6-1), released September 25, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-100073
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0010
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 25, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:  ext4: fix transaction overflow during writeback  Commit 95ad8ee45cdb ("ext4: correct the reserved credits for extent conversion") was correct to note that we need to reserve enough credits for all extents possibly underlying a large folio. However it was too eager to reduce the number of reserved credits. Extent conversion may not only need to touch several leaf extent blocks, it may also need to split extents - for example a single large unwritten extent may need to be split into many small written ones in case of sparse folio dirtying. This can thus result not only in extent leaf modifications but also in a need to allocate new extent tree nodes. As a result the reserved transaction credits were not sufficient in some corner cases. Use ext4_meta_trans_blocks() for correct upper bound credit estimate.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 14 | 7.2.6-1 | [DEBIAN-CVE-2026-100073](https://patchblox.com/security/data/fix/linux/debian-cve-2026-100073.md) | Sep 25, 2026 |

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Data as of 2026-11-12T01:51:14Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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