# CVE-2025-38032: mr: consolidate the ipmr_can_free_table() checks.

> A null pointer dereference in the Linux kernel's IP multicast routing cleanup path can cause a system crash, requiring a kernel patch.

- **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:** 18 Jun 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-38032, GHSA-6p5g-pg67-9qvf, UBUNTU-CVE-2025-38032

## What is CVE-2025-38032?

CVE-2025-38032 is a medium-severity vulnerability in Linux kernel, published on 18 Jun 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:

mr: consolidate the ipmr_can_free_table() checks.

Guoyu Yin reported a splat in the ipmr netns cleanup path:

WARNING: CPU: 2 PID: 14564 at net/ipv4/ipmr.c:440 ipmr_free_table net/ipv4/ipmr.c:440 [inline]
WARNING: CPU: 2 PID: 14564 at net/ipv4/ipmr.c:440 ipmr_rules_exit+0x135/0x1c0 net/ipv4/ipmr.c:361
Modules linked in:
CPU: 2 UID: 0 PID: 14564 Comm: syz.4.838 Not tainted 6.14.0 #1
Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:ipmr_free_table net/ipv4/ipmr.c:440 [inline]
RIP: 0010:ipmr_rules_exit+0x135/0x1c0 net/ipv4/ipmr.c:361
Code: ff df 48 c1 ea 03 80 3c 02 00 75 7d 48 c7 83 60 05 00 00 00 00 00 00 5b 5d 41 5c 41 5d 41 5e e9 71 67 7f 00 e8 4c 2d 8a fd 90 <0f> 0b 90 eb 93 e8 41 2d 8a fd 0f b6 2d 80 54 ea 01 31 ff 89 ee e8
RSP: 0018:ffff888109547c58 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888108c12dc0 RCX: ffffffff83e09868
RDX: ffff8881022b3300 RSI: ffffffff83e098d4 RDI: 0000000000000005
RBP: ffff888104288000 R08: 0000000000000000 R09: ffffed10211825c9
R10: 0000000000000001 R11: ffff88801816c4a0 R12: 0000000000000001
R13: ffff888108c13320 R14: ffff888108c12dc0 R15: fffffbfff0b74058
FS:  00007f84f39316c0(0000) GS:ffff88811b100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f84f3930f98 CR3: 0000000113b56000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 ipmr_net_exit_batch+0x50/0x90 net/ipv4/ipmr.c:3160
 ops_exit_list+0x10c/0x160 net/core/net_namespace.c:177
 setup_net+0x47d/0x8e0 net/core/net_namespace.c:394
 copy_net_ns+0x25d/0x410 net/core/net_namespace.c:516
 create_new_namespaces+0x3f6/0xaf0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xc3/0x180 kernel/nsproxy.c:228
 ksys_unshare+0x78d/0x9a0 kernel/fork.c:3342
 __do_sys_unshare kernel/fork.c:3413 [inline]
 __se_sys_unshare kernel/fork.c:3411 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:3411
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xa6/0x1a0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f84f532cc29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f84f3931038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f84f5615fa0 RCX: 00007f84f532cc29
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000400
RBP: 00007f84f53fba18 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f84f5615fa0 R15: 00007fff51c5f328
 </TASK>

The running kernel has CONFIG_IP_MROUTE_MULTIPLE_TABLES disabled, and
the sanity check for such build is still too loose.

Address the issue consolidating the relevant sanity check in a single
helper regardless of the kernel configuration. Also share it between
the ipv4 and ipv6 code.

## Which versions are affected by CVE-2025-38032?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-38032?

Apply the vendor's patch.

## Is CVE-2025-38032 being exploited?

There is no known exploitation of CVE-2025-38032 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-2025-38032 and fix it if it is affected.

What it is: CVE-2025-38032 is a medium-severity vulnerability in Linux kernel, published on 18 Jun 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-2025-38032 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-2025-38032/ (Markdown: https://insights.sbomify.com/CVE-2025-38032/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38032
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38032
- OSV: https://osv.dev/vulnerability/CVE-2025-38032

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-38032/
Summaries are generated and may contain mistakes; the official description above is the record.