# CVE-2023-54170: keys: Fix linking a duplicate key to a keyring's assoc_array

> A local attacker can trigger a kernel crash by causing duplicate key linking in the keyring assoc_array during DNS queries.

- **Severity:** Not scored
- **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:** 30 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-54170, DEBIAN-CVE-2023-54170, GHSA-r3pm-w3wq-c59c, UBUNTU-CVE-2023-54170

## What is CVE-2023-54170?

CVE-2023-54170 is a denial of service vulnerability in Linux, published on 30 Dec 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:

keys: Fix linking a duplicate key to a keyring's assoc_array

When making a DNS query inside the kernel using dns_query(), the request
code can in rare cases end up creating a duplicate index key in the
assoc_array of the destination keyring. It is eventually found by
a BUG_ON() check in the assoc_array implementation and results in
a crash.

Example report:
[2158499.700025] kernel BUG at ../lib/assoc_array.c:652!
[2158499.700039] invalid opcode: 0000 [#1] SMP PTI
[2158499.700065] CPU: 3 PID: 31985 Comm: kworker/3:1 Kdump: loaded Not tainted 5.3.18-150300.59.90-default #1 SLE15-SP3
[2158499.700096] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020
[2158499.700351] Workqueue: cifsiod cifs_resolve_server [cifs]
[2158499.700380] RIP: 0010:assoc_array_insert+0x85f/0xa40
[2158499.700401] Code: ff 74 2b 48 8b 3b 49 8b 45 18 4c 89 e6 48 83 e7 fe e8 95 ec 74 00 3b 45 88 7d db 85 c0 79 d4 0f 0b 0f 0b 0f 0b e8 41 f2 be ff <0f> 0b 0f 0b 81 7d 88 ff ff ff 7f 4c 89 eb 4c 8b ad 58 ff ff ff 0f
[2158499.700448] RSP: 0018:ffffc0bd6187faf0 EFLAGS: 00010282
[2158499.700470] RAX: ffff9f1ea7da2fe8 RBX: ffff9f1ea7da2fc1 RCX: 0000000000000005
[2158499.700492] RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000000
[2158499.700515] RBP: ffffc0bd6187fbb0 R08: ffff9f185faf1100 R09: 0000000000000000
[2158499.700538] R10: ffff9f1ea7da2cc0 R11: 000000005ed8cec8 R12: ffffc0bd6187fc28
[2158499.700561] R13: ffff9f15feb8d000 R14: ffff9f1ea7da2fc0 R15: ffff9f168dc0d740
[2158499.700585] FS:  0000000000000000(0000) GS:ffff9f185fac0000(0000) knlGS:0000000000000000
[2158499.700610] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[2158499.700630] CR2: 00007fdd94fca238 CR3: 0000000809d8c006 CR4: 00000000003706e0
[2158499.700702] Call Trace:
[2158499.700741]  ? key_alloc+0x447/0x4b0
[2158499.700768]  ? __key_link_begin+0x43/0xa0
[2158499.700790]  __key_link_begin+0x43/0xa0
[2158499.700814]  request_key_and_link+0x2c7/0x730
[2158499.700847]  ? dns_resolver_read+0x20/0x20 [dns_resolver]
[2158499.700873]  ? key_default_cmp+0x20/0x20
[2158499.700898]  request_key_tag+0x43/0xa0
[2158499.700926]  dns_query+0x114/0x2ca [dns_resolver]
[2158499.701127]  dns_resolve_server_name_to_ip+0x194/0x310 [cifs]
[2158499.701164]  ? scnprintf+0x49/0x90
[2158499.701190]  ? __switch_to_asm+0x40/0x70
[2158499.701211]  ? __switch_to_asm+0x34/0x70
[2158499.701405]  reconn_set_ipaddr_from_hostname+0x81/0x2a0 [cifs]
[2158499.701603]  cifs_resolve_server+0x4b/0xd0 [cifs]
[2158499.701632]  process_one_work+0x1f8/0x3e0
[2158499.701658]  worker_thread+0x2d/0x3f0
[2158499.701682]  ? process_one_work+0x3e0/0x3e0
[2158499.701703]  kthread+0x10d/0x130
[2158499.701723]  ? kthread_park+0xb0/0xb0
[2158499.701746]  ret_from_fork+0x1f/0x40

The situation occurs as follows:
* Some kernel facility invokes dns_query() to resolve a hostname, for
  example, "abcdef". The function registers its global DNS resolver
  cache as current->cred.thread_keyring and passes the query to
  request_key_net() -> request_key_tag() -> request_key_and_link().
* Function request_key_and_link() creates a keyring_search_context
  object. Its match_data.cmp method gets set via a call to
  type->match_preparse() (resolves to dns_resolver_match_preparse()) to
  dns_resolver_cmp().
* Function request_key_and_link() continues and invokes
  search_process_keyrings_rcu() which returns that a given key was not
  found. The control is then passed to request_key_and_link() ->
  construct_alloc_key().
* Concurrently to that, a second task similarly makes a DNS query for
  "abcdef." and its result gets inserted into the DNS resolver cache.
* Back on the first task, function construct_alloc_key() first runs
  __key_link_begin() to determine an assoc_array_edit operation to
  insert a new key. Index keys in the array are compared exactly as-is,
  using keyring_compare_object(). The operation 
---truncated---

## Which versions are affected by CVE-2023-54170?


## How do I fix CVE-2023-54170?

Apply the vendor's patch.

## Is CVE-2023-54170 being exploited?

There is no known exploitation of CVE-2023-54170 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-54170 and fix it if it is affected.

What it is: CVE-2023-54170 is a denial of service vulnerability in Linux, published on 30 Dec 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-2023-54170 in the wild and no public exploit code.

Affected product: Linux. 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-2023-54170/ (Markdown: https://insights.sbomify.com/CVE-2023-54170/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-54170
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-54170
- OSV: https://osv.dev/vulnerability/CVE-2023-54170

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-54170/
Summaries are generated and may contain mistakes; the official description above is the record.