# CVE-2023-52698: calipso: fix memory leak in netlbl_calipso_add_pass()

> A memory leak in the Linux kernel's Calipso module can lead to resource exhaustion and denial of service when IPv6 is disabled.

- **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:** 17 May 2024
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-52698, DEBIAN-CVE-2023-52698, GHSA-2xxj-gwfx-rr2c, UBUNTU-CVE-2023-52698

## What is CVE-2023-52698?

CVE-2023-52698 is a medium-severity memory corruption vulnerability in Linux kernel, published on 17 May 2024. 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:

calipso: fix memory leak in netlbl_calipso_add_pass()

If IPv6 support is disabled at boot (ipv6.disable=1),
the calipso_init() -> netlbl_calipso_ops_register() function isn't called,
and the netlbl_calipso_ops_get() function always returns NULL.
In this case, the netlbl_calipso_add_pass() function allocates memory
for the doi_def variable but doesn't free it with the calipso_doi_free().

BUG: memory leak
unreferenced object 0xffff888011d68180 (size 64):
  comm "syz-executor.1", pid 10746, jiffies 4295410986 (age 17.928s)
  hex dump (first 32 bytes):
    00 00 00 00 02 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:
    [<...>] kmalloc include/linux/slab.h:552 [inline]
    [<...>] netlbl_calipso_add_pass net/netlabel/netlabel_calipso.c:76 [inline]
    [<...>] netlbl_calipso_add+0x22e/0x4f0 net/netlabel/netlabel_calipso.c:111
    [<...>] genl_family_rcv_msg_doit+0x22f/0x330 net/netlink/genetlink.c:739
    [<...>] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
    [<...>] genl_rcv_msg+0x341/0x5a0 net/netlink/genetlink.c:800
    [<...>] netlink_rcv_skb+0x14d/0x440 net/netlink/af_netlink.c:2515
    [<...>] genl_rcv+0x29/0x40 net/netlink/genetlink.c:811
    [<...>] netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
    [<...>] netlink_unicast+0x54b/0x800 net/netlink/af_netlink.c:1339
    [<...>] netlink_sendmsg+0x90a/0xdf0 net/netlink/af_netlink.c:1934
    [<...>] sock_sendmsg_nosec net/socket.c:651 [inline]
    [<...>] sock_sendmsg+0x157/0x190 net/socket.c:671
    [<...>] ____sys_sendmsg+0x712/0x870 net/socket.c:2342
    [<...>] ___sys_sendmsg+0xf8/0x170 net/socket.c:2396
    [<...>] __sys_sendmsg+0xea/0x1b0 net/socket.c:2429
    [<...>] do_syscall_64+0x30/0x40 arch/x86/entry/common.c:46
    [<...>] entry_SYSCALL_64_after_hwframe+0x61/0xc6

Found by InfoTeCS on behalf of Linux Verification Center
(linuxtesting.org) with Syzkaller

[PM: merged via the LSM tree at Jakub Kicinski request]

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2023-52698?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-52698?

Apply the vendor's patch.

## Is CVE-2023-52698 being exploited?

There is no known exploitation of CVE-2023-52698 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-2023-52698 and fix it if it is affected.

What it is: CVE-2023-52698 is a medium-severity memory corruption vulnerability in Linux kernel, published on 17 May 2024. 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-2023-52698 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-2023-52698/ (Markdown: https://insights.sbomify.com/CVE-2023-52698/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-52698
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-52698
- OSV: https://osv.dev/vulnerability/CVE-2023-52698

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-52698/
Summaries are generated and may contain mistakes; the official description above is the record.