# CVE-2022-48906: mptcp: Correctly set DATA_FIN timeout when number of retransmits is large

> A shift-out-of-bounds error in the Linux kernel MPTCP module can cause a denial of service when handling large retransmit counts.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 22 Aug 2024
- **Updated:** 23 May 2026
- **Also known as:** DEBIAN-CVE-2022-48906, GHSA-wvmv-3h72-2xxc, UBUNTU-CVE-2022-48906

## What is CVE-2022-48906?

CVE-2022-48906 is a medium-severity vulnerability in Linux kernel, published on 22 Aug 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

mptcp: Correctly set DATA_FIN timeout when number of retransmits is large

Syzkaller with UBSAN uncovered a scenario where a large number of
DATA_FIN retransmits caused a shift-out-of-bounds in the DATA_FIN
timeout calculation:

================================================================================
UBSAN: shift-out-of-bounds in net/mptcp/protocol.c:470:29
shift exponent 32 is too large for 32-bit type 'unsigned int'
CPU: 1 PID: 13059 Comm: kworker/1:0 Not tainted 5.17.0-rc2-00630-g5fbf21c90c60 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Workqueue: events mptcp_worker
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 ubsan_epilogue+0xb/0x5a lib/ubsan.c:151
 __ubsan_handle_shift_out_of_bounds.cold+0xb2/0x20e lib/ubsan.c:330
 mptcp_set_datafin_timeout net/mptcp/protocol.c:470 [inline]
 __mptcp_retrans.cold+0x72/0x77 net/mptcp/protocol.c:2445
 mptcp_worker+0x58a/0xa70 net/mptcp/protocol.c:2528
 process_one_work+0x9df/0x16d0 kernel/workqueue.c:2307
 worker_thread+0x95/0xe10 kernel/workqueue.c:2454
 kthread+0x2f4/0x3b0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
================================================================================

This change limits the maximum timeout by limiting the size of the
shift, which keeps all intermediate values in-bounds.

## Which versions are affected by CVE-2022-48906?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-48906?

Apply the vendor's patch.

## Is CVE-2022-48906 being exploited?

There is no known exploitation of CVE-2022-48906 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-48906 and fix it if it is affected.

What it is: CVE-2022-48906 is a medium-severity vulnerability in Linux kernel, published on 22 Aug 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-48906 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2022-48906/ (Markdown: https://insights.sbomify.com/CVE-2022-48906/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-48906
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-48906
- OSV: https://osv.dev/vulnerability/CVE-2022-48906

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-48906/
Summaries are generated and may contain mistakes; the official description above is the record.