# CVE-2022-49928: SUNRPC: Fix null-ptr-deref when xps sysfs alloc failed

> A null pointer dereference in the Linux kernel SUNRPC module can cause a system crash when sysfs allocation fails.

- **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:** 1 May 2025
- **Updated:** 5 Aug 2026
- **Also known as:** DEBIAN-CVE-2022-49928, GHSA-rrmw-h9hh-7q5m, UBUNTU-CVE-2022-49928

## What is CVE-2022-49928?

CVE-2022-49928 is a high-severity vulnerability in Linux kernel, published on 1 May 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:

SUNRPC: Fix null-ptr-deref when xps sysfs alloc failed

There is a null-ptr-deref when xps sysfs alloc failed:
  BUG: KASAN: null-ptr-deref in sysfs_do_create_link_sd+0x40/0xd0
  Read of size 8 at addr 0000000000000030 by task gssproxy/457

  CPU: 5 PID: 457 Comm: gssproxy Not tainted 6.0.0-09040-g02357b27ee03 #9
  Call Trace:
   <TASK>
   dump_stack_lvl+0x34/0x44
   kasan_report+0xa3/0x120
   sysfs_do_create_link_sd+0x40/0xd0
   rpc_sysfs_client_setup+0x161/0x1b0
   rpc_new_client+0x3fc/0x6e0
   rpc_create_xprt+0x71/0x220
   rpc_create+0x1d4/0x350
   gssp_rpc_create+0xc3/0x160
   set_gssp_clnt+0xbc/0x140
   write_gssp+0x116/0x1a0
   proc_reg_write+0xd6/0x130
   vfs_write+0x177/0x690
   ksys_write+0xb9/0x150
   do_syscall_64+0x35/0x80
   entry_SYSCALL_64_after_hwframe+0x46/0xb0

When the xprt_switch sysfs alloc failed, should not add xprt and
switch sysfs to it, otherwise, maybe null-ptr-deref; also initialize
the 'xps_sysfs' to NULL to avoid oops when destroy it.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2022-49928?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-49928?

Apply the vendor's patch.

## Is CVE-2022-49928 being exploited?

There is no known exploitation of CVE-2022-49928 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-2022-49928 and fix it if it is affected.

What it is: CVE-2022-49928 is a high-severity vulnerability in Linux kernel, published on 1 May 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-2022-49928 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-2022-49928/ (Markdown: https://insights.sbomify.com/CVE-2022-49928/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-49928
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-49928
- OSV: https://osv.dev/vulnerability/CVE-2022-49928

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-49928/
Summaries are generated and may contain mistakes; the official description above is the record.