# CVE-2022-49930: RDMA/hns: Fix NULL pointer problem in free_mr_init()

> A local attacker can trigger a kernel crash in the RDMA hns driver by exploiting a race condition leading to a NULL pointer dereference.

- **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:** 1 May 2025
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2022-49930, GHSA-g77v-vvxx-rcj7, UBUNTU-CVE-2022-49930

## What is CVE-2022-49930?

CVE-2022-49930 is a medium-severity vulnerability in Linux kernel, published on 1 May 2025. 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:

RDMA/hns: Fix NULL pointer problem in free_mr_init()

Lock grab occurs in a concurrent scenario, resulting in stepping on a NULL
pointer.  It should be init mutex_init() first before use the lock.

  Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
  Call trace:
   __mutex_lock.constprop.0+0xd0/0x5c0
   __mutex_lock_slowpath+0x1c/0x2c
   mutex_lock+0x44/0x50
   free_mr_send_cmd_to_hw+0x7c/0x1c0 [hns_roce_hw_v2]
   hns_roce_v2_dereg_mr+0x30/0x40 [hns_roce_hw_v2]
   hns_roce_dereg_mr+0x4c/0x130 [hns_roce_hw_v2]
   ib_dereg_mr_user+0x54/0x124
   uverbs_free_mr+0x24/0x30
   destroy_hw_idr_uobject+0x38/0x74
   uverbs_destroy_uobject+0x48/0x1c4
   uobj_destroy+0x74/0xcc
   ib_uverbs_cmd_verbs+0x368/0xbb0
   ib_uverbs_ioctl+0xec/0x1a4
   __arm64_sys_ioctl+0xb4/0x100
   invoke_syscall+0x50/0x120
   el0_svc_common.constprop.0+0x58/0x190
   do_el0_svc+0x30/0x90
   el0_svc+0x2c/0xb4
   el0t_64_sync_handler+0x1a4/0x1b0
   el0t_64_sync+0x19c/0x1a0

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2022-49930?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-49930?

Apply the vendor's patch.

## Is CVE-2022-49930 being exploited?

There is no known exploitation of CVE-2022-49930 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-2022-49930 and fix it if it is affected.

What it is: CVE-2022-49930 is a medium-severity vulnerability in Linux kernel, published on 1 May 2025. 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-2022-49930 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-2022-49930/ (Markdown: https://insights.sbomify.com/CVE-2022-49930/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-49930
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-49930
- OSV: https://osv.dev/vulnerability/CVE-2022-49930

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-49930/
Summaries are generated and may contain mistakes; the official description above is the record.