# CVE-2022-49865: ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network

> An uninitialized memory leak in the Linux kernel IPv6 address label handling allows attackers to read sensitive kernel memory.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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-2022-49865, GHSA-5jv4-93fg-hvqc, UBUNTU-CVE-2022-49865

## What is CVE-2022-49865?

CVE-2022-49865 is a high-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:

ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network

When copying a `struct ifaddrlblmsg` to the network, __ifal_reserved
remained uninitialized, resulting in a 1-byte infoleak:

  BUG: KMSAN: kernel-network-infoleak in __netdev_start_xmit ./include/linux/netdevice.h:4841
   __netdev_start_xmit ./include/linux/netdevice.h:4841
   netdev_start_xmit ./include/linux/netdevice.h:4857
   xmit_one net/core/dev.c:3590
   dev_hard_start_xmit+0x1dc/0x800 net/core/dev.c:3606
   __dev_queue_xmit+0x17e8/0x4350 net/core/dev.c:4256
   dev_queue_xmit ./include/linux/netdevice.h:3009
   __netlink_deliver_tap_skb net/netlink/af_netlink.c:307
   __netlink_deliver_tap+0x728/0xad0 net/netlink/af_netlink.c:325
   netlink_deliver_tap net/netlink/af_netlink.c:338
   __netlink_sendskb net/netlink/af_netlink.c:1263
   netlink_sendskb+0x1d9/0x200 net/netlink/af_netlink.c:1272
   netlink_unicast+0x56d/0xf50 net/netlink/af_netlink.c:1360
   nlmsg_unicast ./include/net/netlink.h:1061
   rtnl_unicast+0x5a/0x80 net/core/rtnetlink.c:758
   ip6addrlbl_get+0xfad/0x10f0 net/ipv6/addrlabel.c:628
   rtnetlink_rcv_msg+0xb33/0x1570 net/core/rtnetlink.c:6082
  ...
  Uninit was created at:
   slab_post_alloc_hook+0x118/0xb00 mm/slab.h:742
   slab_alloc_node mm/slub.c:3398
   __kmem_cache_alloc_node+0x4f2/0x930 mm/slub.c:3437
   __do_kmalloc_node mm/slab_common.c:954
   __kmalloc_node_track_caller+0x117/0x3d0 mm/slab_common.c:975
   kmalloc_reserve net/core/skbuff.c:437
   __alloc_skb+0x27a/0xab0 net/core/skbuff.c:509
   alloc_skb ./include/linux/skbuff.h:1267
   nlmsg_new ./include/net/netlink.h:964
   ip6addrlbl_get+0x490/0x10f0 net/ipv6/addrlabel.c:608
   rtnetlink_rcv_msg+0xb33/0x1570 net/core/rtnetlink.c:6082
   netlink_rcv_skb+0x299/0x550 net/netlink/af_netlink.c:2540
   rtnetlink_rcv+0x26/0x30 net/core/rtnetlink.c:6109
   netlink_unicast_kernel net/netlink/af_netlink.c:1319
   netlink_unicast+0x9ab/0xf50 net/netlink/af_netlink.c:1345
   netlink_sendmsg+0xebc/0x10f0 net/netlink/af_netlink.c:1921
  ...

This patch ensures that the reserved field is always initialized.

Weakness: CWE-909 (Missing Initialization of Resource)

## Which versions are affected by CVE-2022-49865?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-49865?

Apply the vendor's patch.

## Is CVE-2022-49865 being exploited?

There is no known exploitation of CVE-2022-49865 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-2022-49865 and fix it if it is affected.

What it is: CVE-2022-49865 is a high-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-2022-49865 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-2022-49865/ (Markdown: https://insights.sbomify.com/CVE-2022-49865/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-49865
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-49865
- OSV: https://osv.dev/vulnerability/CVE-2022-49865

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-49865/
Summaries are generated and may contain mistakes; the official description above is the record.