# CVE-2026-63820: linux: In the Linux kernel, the following vulnerability has been resolved:  f2fs: fix missing read bio submission on large f...

CVE-2026-63820 is fixed in linux on 1 platform by DEBIAN-CVE-2026-63820 (version 7.1.3-1), released July 20, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-63820
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0020
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 19, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:  f2fs: fix missing read bio submission on large folio error  f2fs_read_data_large_folio() can keep a read bio across multiple readahead folios.  If a later folio hits an error before any of its blocks are added to the bio, folio_in_bio is false and the current error path returns immediately after ending that folio.  This can leave the bio accumulated for earlier folios unsubmitted.  Those folios then never receive read completion, and readers can wait indefinitely on the locked folios.  Route errors through the common out path so any pending bio is submitted before returning.  Stop consuming more readahead folios once an error is seen, and only wait on and clear the current folio when it was actually added to the bio.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 14 | 7.1.3-1 | [DEBIAN-CVE-2026-63820](https://patchblox.com/security/data/fix/linux/debian-cve-2026-63820.md) | Jul 20, 2026 |

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Data as of 2026-11-10T01:44:33Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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