# CVE-2022-49916: rose: Fix NULL pointer dereference in rose_send_frame()

> A NULL pointer dereference in the Linux kernel's ROSE protocol allows local attackers to cause a system crash via crafted network operations.

- **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:** 23 May 2026
- **Also known as:** DEBIAN-CVE-2022-49916, GHSA-7qcm-qx74-j7hr, UBUNTU-CVE-2022-49916

## What is CVE-2022-49916?

CVE-2022-49916 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:

rose: Fix NULL pointer dereference in rose_send_frame()

The syzkaller reported an issue:

KASAN: null-ptr-deref in range [0x0000000000000380-0x0000000000000387]
CPU: 0 PID: 4069 Comm: kworker/0:15 Not tainted 6.0.0-syzkaller-02734-g0326074ff465 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Workqueue: rcu_gp srcu_invoke_callbacks
RIP: 0010:rose_send_frame+0x1dd/0x2f0 net/rose/rose_link.c:101
Call Trace:
 <IRQ>
 rose_transmit_clear_request+0x1d5/0x290 net/rose/rose_link.c:255
 rose_rx_call_request+0x4c0/0x1bc0 net/rose/af_rose.c:1009
 rose_loopback_timer+0x19e/0x590 net/rose/rose_loopback.c:111
 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474
 expire_timers kernel/time/timer.c:1519 [inline]
 __run_timers.part.0+0x674/0xa80 kernel/time/timer.c:1790
 __run_timers kernel/time/timer.c:1768 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803
 __do_softirq+0x1d0/0x9c8 kernel/softirq.c:571
 [...]
 </IRQ>

It triggers NULL pointer dereference when 'neigh->dev->dev_addr' is
called in the rose_send_frame(). It's the first occurrence of the
`neigh` is in rose_loopback_timer() as `rose_loopback_neigh', and
the 'dev' in 'rose_loopback_neigh' is initialized sa nullptr.

It had been fixed by commit 3b3fd068c56e3fbea30090859216a368398e39bf
("rose: Fix Null pointer dereference in rose_send_frame()") ever.
But it's introduced by commit 3c53cd65dece47dd1f9d3a809f32e59d1d87b2b8
("rose: check NULL rose_loopback_neigh->loopback") again.

We fix it by add NULL check in rose_transmit_clear_request(). When
the 'dev' in 'neigh' is NULL, we don't reply the request and just
clear it.

syzkaller don't provide repro, and I provide a syz repro like:
r0 = syz_init_net_socket$bt_sco(0x1f, 0x5, 0x2)
ioctl$sock_inet_SIOCSIFFLAGS(r0, 0x8914, &(0x7f0000000180)={'rose0\x00', 0x201})
r1 = syz_init_net_socket$rose(0xb, 0x5, 0x0)
bind$rose(r1, &(0x7f00000000c0)=@full={0xb, @dev, @null, 0x0, [@null, @null, @netrom, @netrom, @default, @null]}, 0x40)
connect$rose(r1, &(0x7f0000000240)=@short={0xb, @dev={0xbb, 0xbb, 0xbb, 0x1, 0x0}, @remote={0xcc, 0xcc, 0xcc, 0xcc, 0xcc, 0xcc, 0x1}, 0x1, @netrom={0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0x0, 0x0}}, 0x1c)

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2022-49916?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-49916?

Apply the vendor's patch.

## Is CVE-2022-49916 being exploited?

There is no known exploitation of CVE-2022-49916 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-2022-49916 and fix it if it is affected.

What it is: CVE-2022-49916 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-2022-49916 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-2022-49916/ (Markdown: https://insights.sbomify.com/CVE-2022-49916/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-49916
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-49916
- OSV: https://osv.dev/vulnerability/CVE-2022-49916

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-49916/
Summaries are generated and may contain mistakes; the official description above is the record.