# CVE-2022-49321: xprtrdma: treat all calls not a bcall when bc_serv is NULL

> A null pointer dereference in the Linux kernel's xprtrdma module allows a remote attacker to cause a system crash via a malformed RPC reply.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 26 Feb 2025
- **Updated:** 5 Aug 2026
- **Also known as:** DEBIAN-CVE-2022-49321, GHSA-vch8-w6r9-fgp2, UBUNTU-CVE-2022-49321

## What is CVE-2022-49321?

CVE-2022-49321 is a high-severity vulnerability in Linux kernel, published on 26 Feb 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:

xprtrdma: treat all calls not a bcall when bc_serv is NULL

When a rdma server returns a fault format reply, nfs v3 client may
treats it as a bcall when bc service is not exist.

The debug message at rpcrdma_bc_receive_call are,

[56579.837169] RPC:       rpcrdma_bc_receive_call: callback XID
00000001, length=20
[56579.837174] RPC:       rpcrdma_bc_receive_call: 00 00 00 01 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 04

After that, rpcrdma_bc_receive_call will meets NULL pointer as,

[  226.057890] BUG: unable to handle kernel NULL pointer dereference at
00000000000000c8
...
[  226.058704] RIP: 0010:_raw_spin_lock+0xc/0x20
...
[  226.059732] Call Trace:
[  226.059878]  rpcrdma_bc_receive_call+0x138/0x327 [rpcrdma]
[  226.060011]  __ib_process_cq+0x89/0x170 [ib_core]
[  226.060092]  ib_cq_poll_work+0x26/0x80 [ib_core]
[  226.060257]  process_one_work+0x1a7/0x360
[  226.060367]  ? create_worker+0x1a0/0x1a0
[  226.060440]  worker_thread+0x30/0x390
[  226.060500]  ? create_worker+0x1a0/0x1a0
[  226.060574]  kthread+0x116/0x130
[  226.060661]  ? kthread_flush_work_fn+0x10/0x10
[  226.060724]  ret_from_fork+0x35/0x40
...

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2022-49321?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-49321?

Apply the vendor's patch.

## Is CVE-2022-49321 being exploited?

There is no known exploitation of CVE-2022-49321 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-2022-49321 and fix it if it is affected.

What it is: CVE-2022-49321 is a high-severity vulnerability in Linux kernel, published on 26 Feb 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-2022-49321 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-2022-49321/ (Markdown: https://insights.sbomify.com/CVE-2022-49321/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-49321
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-49321
- OSV: https://osv.dev/vulnerability/CVE-2022-49321

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-49321/
Summaries are generated and may contain mistakes; the official description above is the record.