# CVE-2023-53563: cpufreq: amd-pstate-ut: Fix kernel panic when loading the driver

> A missing resource release in the amd-pstate-ut kernel driver causes a system hang or panic when changing CPU frequency modes.

- **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:** 4 Oct 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-53563, DEBIAN-CVE-2023-53563, GHSA-jjx2-jhcm-j26c, UBUNTU-CVE-2023-53563

## What is CVE-2023-53563?

CVE-2023-53563 is a medium-severity denial of service vulnerability in Linux kernel, published on 4 Oct 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:

cpufreq: amd-pstate-ut: Fix kernel panic when loading the driver

After loading the amd-pstate-ut driver, amd_pstate_ut_check_perf()
and amd_pstate_ut_check_freq() use cpufreq_cpu_get() to get the policy
of the CPU and mark it as busy.

In these functions, cpufreq_cpu_put() should be used to release the
policy, but it is not, so any other entity trying to access the policy
is blocked indefinitely.

One such scenario is when amd_pstate mode is changed, leading to the
following splat:

[ 1332.103727] INFO: task bash:2929 blocked for more than 120 seconds.
[ 1332.110001]       Not tainted 6.5.0-rc2-amd-pstate-ut #5
[ 1332.115315] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1332.123140] task:bash            state:D stack:0     pid:2929  ppid:2873   flags:0x00004006
[ 1332.123143] Call Trace:
[ 1332.123145]  <TASK>
[ 1332.123148]  __schedule+0x3c1/0x16a0
[ 1332.123154]  ? _raw_read_lock_irqsave+0x2d/0x70
[ 1332.123157]  schedule+0x6f/0x110
[ 1332.123160]  schedule_timeout+0x14f/0x160
[ 1332.123162]  ? preempt_count_add+0x86/0xd0
[ 1332.123165]  __wait_for_common+0x92/0x190
[ 1332.123168]  ? __pfx_schedule_timeout+0x10/0x10
[ 1332.123170]  wait_for_completion+0x28/0x30
[ 1332.123173]  cpufreq_policy_put_kobj+0x4d/0x90
[ 1332.123177]  cpufreq_policy_free+0x157/0x1d0
[ 1332.123178]  ? preempt_count_add+0x58/0xd0
[ 1332.123180]  cpufreq_remove_dev+0xb6/0x100
[ 1332.123182]  subsys_interface_unregister+0x114/0x120
[ 1332.123185]  ? preempt_count_add+0x58/0xd0
[ 1332.123187]  ? __pfx_amd_pstate_change_driver_mode+0x10/0x10
[ 1332.123190]  cpufreq_unregister_driver+0x3b/0xd0
[ 1332.123192]  amd_pstate_change_driver_mode+0x1e/0x50
[ 1332.123194]  store_status+0xe9/0x180
[ 1332.123197]  dev_attr_store+0x1b/0x30
[ 1332.123199]  sysfs_kf_write+0x42/0x50
[ 1332.123202]  kernfs_fop_write_iter+0x143/0x1d0
[ 1332.123204]  vfs_write+0x2df/0x400
[ 1332.123208]  ksys_write+0x6b/0xf0
[ 1332.123210]  __x64_sys_write+0x1d/0x30
[ 1332.123213]  do_syscall_64+0x60/0x90
[ 1332.123216]  ? fpregs_assert_state_consistent+0x2e/0x50
[ 1332.123219]  ? exit_to_user_mode_prepare+0x49/0x1a0
[ 1332.123223]  ? irqentry_exit_to_user_mode+0xd/0x20
[ 1332.123225]  ? irqentry_exit+0x3f/0x50
[ 1332.123226]  ? exc_page_fault+0x8e/0x190
[ 1332.123228]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[ 1332.123232] RIP: 0033:0x7fa74c514a37
[ 1332.123234] RSP: 002b:00007ffe31dd0788 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 1332.123238] RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007fa74c514a37
[ 1332.123239] RDX: 0000000000000008 RSI: 000055e27c447aa0 RDI: 0000000000000001
[ 1332.123241] RBP: 000055e27c447aa0 R08: 00007fa74c5d1460 R09: 000000007fffffff
[ 1332.123242] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000008
[ 1332.123244] R13: 00007fa74c61a780 R14: 00007fa74c616600 R15: 00007fa74c615a00
[ 1332.123247]  </TASK>

Fix this by calling cpufreq_cpu_put() wherever necessary.

[ rjw: Subject and changelog edits ]

## Which versions are affected by CVE-2023-53563?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-53563?

Apply the vendor's patch.

## Is CVE-2023-53563 being exploited?

There is no known exploitation of CVE-2023-53563 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-2023-53563 and fix it if it is affected.

What it is: CVE-2023-53563 is a medium-severity denial of service vulnerability in Linux kernel, published on 4 Oct 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-2023-53563 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-2023-53563/ (Markdown: https://insights.sbomify.com/CVE-2023-53563/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53563
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53563
- OSV: https://osv.dev/vulnerability/CVE-2023-53563

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53563/
Summaries are generated and may contain mistakes; the official description above is the record.