# CVE-2023-54195: rxrpc: Fix timeout of a call that hasn't yet been granted a channel

> A null pointer dereference in the Linux kernel's rxrpc module can cause a system crash when a call times out before a channel is granted.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-54195, GHSA-vmxf-qh3m-3qqj, UBUNTU-CVE-2023-54195

## What is CVE-2023-54195?

CVE-2023-54195 is a vulnerability in Linux, published on 30 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

rxrpc: Fix timeout of a call that hasn't yet been granted a channel

afs_make_call() calls rxrpc_kernel_begin_call() to begin a call (which may
get stalled in the background waiting for a connection to become
available); it then calls rxrpc_kernel_set_max_life() to set the timeouts -
but that starts the call timer so the call timer might then expire before
we get a connection assigned - leading to the following oops if the call
stalled:

	BUG: kernel NULL pointer dereference, address: 0000000000000000
	...
	CPU: 1 PID: 5111 Comm: krxrpcio/0 Not tainted 6.3.0-rc7-build3+ #701
	RIP: 0010:rxrpc_alloc_txbuf+0xc0/0x157
	...
	Call Trace:
	 <TASK>
	 rxrpc_send_ACK+0x50/0x13b
	 rxrpc_input_call_event+0x16a/0x67d
	 rxrpc_io_thread+0x1b6/0x45f
	 ? _raw_spin_unlock_irqrestore+0x1f/0x35
	 ? rxrpc_input_packet+0x519/0x519
	 kthread+0xe7/0xef
	 ? kthread_complete_and_exit+0x1b/0x1b
	 ret_from_fork+0x22/0x30

Fix this by noting the timeouts in struct rxrpc_call when the call is
created.  The timer will be started when the first packet is transmitted.

It shouldn't be possible to trigger this directly from userspace through
AF_RXRPC as sendmsg() will return EBUSY if the call is in the
waiting-for-conn state if it dropped out of the wait due to a signal.

## Which versions are affected by CVE-2023-54195?


## How do I fix CVE-2023-54195?

Apply the vendor's patch.

## Is CVE-2023-54195 being exploited?

There is no known exploitation of CVE-2023-54195 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-54195 and fix it if it is affected.

What it is: CVE-2023-54195 is a vulnerability in Linux, published on 30 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-54195 in the wild and no public exploit code.

Affected product: Linux. 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-2023-54195/ (Markdown: https://insights.sbomify.com/CVE-2023-54195/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-54195
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-54195
- OSV: https://osv.dev/vulnerability/CVE-2023-54195

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-54195/
Summaries are generated and may contain mistakes; the official description above is the record.