# CVE-2025-37894: net: use sock_gen_put() when sk_state is TCP_TIME_WAIT

> A null pointer dereference in the Linux kernel network stack causes a crash when handling TCP TIME_WAIT sockets, leading to denial of service.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 20 May 2025
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2025-37894, DEBIAN-CVE-2025-37894, GHSA-7mrf-fv7q-m57f, UBUNTU-CVE-2025-37894

## What is CVE-2025-37894?

CVE-2025-37894 is a critical vulnerability in Linux kernel, published on 20 May 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

net: use sock_gen_put() when sk_state is TCP_TIME_WAIT

It is possible for a pointer of type struct inet_timewait_sock to be
returned from the functions __inet_lookup_established() and
__inet6_lookup_established(). This can cause a crash when the
returned pointer is of type struct inet_timewait_sock and
sock_put() is called on it. The following is a crash call stack that
shows sk->sk_wmem_alloc being accessed in sk_free() during the call to
sock_put() on a struct inet_timewait_sock pointer. To avoid this issue,
use sock_gen_put() instead of sock_put() when sk->sk_state
is TCP_TIME_WAIT.

mrdump.ko        ipanic() + 120
vmlinux          notifier_call_chain(nr_to_call=-1, nr_calls=0) + 132
vmlinux          atomic_notifier_call_chain(val=0) + 56
vmlinux          panic() + 344
vmlinux          add_taint() + 164
vmlinux          end_report() + 136
vmlinux          kasan_report(size=0) + 236
vmlinux          report_tag_fault() + 16
vmlinux          do_tag_recovery() + 16
vmlinux          __do_kernel_fault() + 88
vmlinux          do_bad_area() + 28
vmlinux          do_tag_check_fault() + 60
vmlinux          do_mem_abort() + 80
vmlinux          el1_abort() + 56
vmlinux          el1h_64_sync_handler() + 124
vmlinux        > 0xFFFFFFC080011294()
vmlinux          __lse_atomic_fetch_add_release(v=0xF2FFFF82A896087C)
vmlinux          __lse_atomic_fetch_sub_release(v=0xF2FFFF82A896087C)
vmlinux          arch_atomic_fetch_sub_release(i=1, v=0xF2FFFF82A896087C)
+ 8
vmlinux          raw_atomic_fetch_sub_release(i=1, v=0xF2FFFF82A896087C)
+ 8
vmlinux          atomic_fetch_sub_release(i=1, v=0xF2FFFF82A896087C) + 8
vmlinux          __refcount_sub_and_test(i=1, r=0xF2FFFF82A896087C,
oldp=0) + 8
vmlinux          __refcount_dec_and_test(r=0xF2FFFF82A896087C, oldp=0) + 8
vmlinux          refcount_dec_and_test(r=0xF2FFFF82A896087C) + 8
vmlinux          sk_free(sk=0xF2FFFF82A8960700) + 28
vmlinux          sock_put() + 48
vmlinux          tcp6_check_fraglist_gro() + 236
vmlinux          tcp6_gro_receive() + 624
vmlinux          ipv6_gro_receive() + 912
vmlinux          dev_gro_receive() + 1116
vmlinux          napi_gro_receive() + 196
ccmni.ko         ccmni_rx_callback() + 208
ccmni.ko         ccmni_queue_recv_skb() + 388
ccci_dpmaif.ko   dpmaif_rxq_push_thread() + 1088
vmlinux          kthread() + 268
vmlinux          0xFFFFFFC08001F30C()

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2025-37894?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-37894?

Apply the vendor's patch.

## Is CVE-2025-37894 being exploited?

There is no known exploitation of CVE-2025-37894 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-2025-37894 and fix it if it is affected.

What it is: CVE-2025-37894 is a critical vulnerability in Linux kernel, published on 20 May 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-37894 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-2025-37894/ (Markdown: https://insights.sbomify.com/CVE-2025-37894/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-37894
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-37894
- OSV: https://osv.dev/vulnerability/CVE-2025-37894

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-37894/
Summaries are generated and may contain mistakes; the official description above is the record.