# CVE-2022-50817: net: hsr: avoid possible NULL deref in skb_clone()

> A null pointer dereference in the Linux kernel HSR protocol allows local attackers to cause a system crash via crafted network packets.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2022-50817, GHSA-wv4w-6f2g-7mq7, UBUNTU-CVE-2022-50817

## What is CVE-2022-50817?

CVE-2022-50817 is a vulnerability in Linux, published on 30 Dec 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:

net: hsr: avoid possible NULL deref in skb_clone()

syzbot got a crash [1] in skb_clone(), caused by a bug
in hsr_get_untagged_frame().

When/if create_stripped_skb_hsr() returns NULL, we must
not attempt to call skb_clone().

While we are at it, replace a WARN_ONCE() by netdev_warn_once().

[1]
general protection fault, probably for non-canonical address 0xdffffc000000000f: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000078-0x000000000000007f]
CPU: 1 PID: 754 Comm: syz-executor.0 Not tainted 6.0.0-syzkaller-02734-g0326074ff465 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
RIP: 0010:skb_clone+0x108/0x3c0 net/core/skbuff.c:1641
Code: 93 02 00 00 49 83 7c 24 28 00 0f 85 e9 00 00 00 e8 5d 4a 29 fa 4c 8d 75 7e 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <0f> b6 04 02 4c 89 f2 83 e2 07 38 d0 7f 08 84 c0 0f 85 9e 01 00 00
RSP: 0018:ffffc90003ccf4e0 EFLAGS: 00010207

RAX: dffffc0000000000 RBX: ffffc90003ccf5f8 RCX: ffffc9000c24b000
RDX: 000000000000000f RSI: ffffffff8751cb13 RDI: 0000000000000000
RBP: 0000000000000000 R08: 00000000000000f0 R09: 0000000000000140
R10: fffffbfff181d972 R11: 0000000000000000 R12: ffff888161fc3640
R13: 0000000000000a20 R14: 000000000000007e R15: ffffffff8dc5f620
FS: 00007feb621e4700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007feb621e3ff8 CR3: 00000001643a9000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
hsr_get_untagged_frame+0x4e/0x610 net/hsr/hsr_forward.c:164
hsr_forward_do net/hsr/hsr_forward.c:461 [inline]
hsr_forward_skb+0xcca/0x1d50 net/hsr/hsr_forward.c:623
hsr_handle_frame+0x588/0x7c0 net/hsr/hsr_slave.c:69
__netif_receive_skb_core+0x9fe/0x38f0 net/core/dev.c:5379
__netif_receive_skb_one_core+0xae/0x180 net/core/dev.c:5483
__netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5599
netif_receive_skb_internal net/core/dev.c:5685 [inline]
netif_receive_skb+0x12f/0x8d0 net/core/dev.c:5744
tun_rx_batched+0x4ab/0x7a0 drivers/net/tun.c:1544
tun_get_user+0x2686/0x3a00 drivers/net/tun.c:1995
tun_chr_write_iter+0xdb/0x200 drivers/net/tun.c:2025
call_write_iter include/linux/fs.h:2187 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x9e9/0xdd0 fs/read_write.c:584
ksys_write+0x127/0x250 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

## Which versions are affected by CVE-2022-50817?


## How do I fix CVE-2022-50817?

Apply the vendor's patch.

## Is CVE-2022-50817 being exploited?

There is no known exploitation of CVE-2022-50817 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-50817 and fix it if it is affected.

What it is: CVE-2022-50817 is a vulnerability in Linux, published on 30 Dec 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-2022-50817 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-2022-50817/ (Markdown: https://insights.sbomify.com/CVE-2022-50817/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-50817
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-50817
- OSV: https://osv.dev/vulnerability/CVE-2022-50817

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-50817/
Summaries are generated and may contain mistakes; the official description above is the record.