# CVE-2023-53649: perf trace: Really free the evsel->priv area

> A memory leak in the Linux kernel perf trace tool can lead to resource exhaustion and denial of service.

- **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:** 7 Oct 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-53649, DEBIAN-CVE-2023-53649, GHSA-933f-4h29-gq7r, UBUNTU-CVE-2023-53649

## What is CVE-2023-53649?

CVE-2023-53649 is a medium-severity denial of service vulnerability in Linux kernel, published on 7 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:

perf trace: Really free the evsel->priv area

In 3cb4d5e00e037c70 ("perf trace: Free syscall tp fields in
evsel->priv") it only was freeing if strcmp(evsel->tp_format->system,
"syscalls") returned zero, while the corresponding initialization of
evsel->priv was being performed if it was _not_ zero, i.e. if the tp
system wasn't 'syscalls'.

Just stop looking for that and free it if evsel->priv was set, which
should be equivalent.

Also use the pre-existing evsel_trace__delete() function.

This resolves these leaks, detected with:

  $ make EXTRA_CFLAGS="-fsanitize=address" BUILD_BPF_SKEL=1 CORESIGHT=1 O=/tmp/build/perf-tools-next -C tools/perf install-bin

  =================================================================
  ==481565==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 40 byte(s) in 1 object(s) allocated from:
      #0 0x7f7343cba097 in calloc (/lib64/libasan.so.8+0xba097)
      #1 0x987966 in zalloc (/home/acme/bin/perf+0x987966)
      #2 0x52f9b9 in evsel_trace__new /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:307
      #3 0x52f9b9 in evsel__syscall_tp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:333
      #4 0x52f9b9 in evsel__init_raw_syscall_tp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:458
      #5 0x52f9b9 in perf_evsel__raw_syscall_newtp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:480
      #6 0x540e8b in trace__add_syscall_newtp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3212
      #7 0x540e8b in trace__run /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3891
      #8 0x540e8b in cmd_trace /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:5156
      #9 0x5ef262 in run_builtin /home/acme/git/perf-tools-next/tools/perf/perf.c:323
      #10 0x4196da in handle_internal_command /home/acme/git/perf-tools-next/tools/perf/perf.c:377
      #11 0x4196da in run_argv /home/acme/git/perf-tools-next/tools/perf/perf.c:421
      #12 0x4196da in main /home/acme/git/perf-tools-next/tools/perf/perf.c:537
      #13 0x7f7342c4a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f)

  Direct leak of 40 byte(s) in 1 object(s) allocated from:
      #0 0x7f7343cba097 in calloc (/lib64/libasan.so.8+0xba097)
      #1 0x987966 in zalloc (/home/acme/bin/perf+0x987966)
      #2 0x52f9b9 in evsel_trace__new /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:307
      #3 0x52f9b9 in evsel__syscall_tp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:333
      #4 0x52f9b9 in evsel__init_raw_syscall_tp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:458
      #5 0x52f9b9 in perf_evsel__raw_syscall_newtp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:480
      #6 0x540dd1 in trace__add_syscall_newtp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3205
      #7 0x540dd1 in trace__run /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3891
      #8 0x540dd1 in cmd_trace /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:5156
      #9 0x5ef262 in run_builtin /home/acme/git/perf-tools-next/tools/perf/perf.c:323
      #10 0x4196da in handle_internal_command /home/acme/git/perf-tools-next/tools/perf/perf.c:377
      #11 0x4196da in run_argv /home/acme/git/perf-tools-next/tools/perf/perf.c:421
      #12 0x4196da in main /home/acme/git/perf-tools-next/tools/perf/perf.c:537
      #13 0x7f7342c4a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f)

  SUMMARY: AddressSanitizer: 80 byte(s) leaked in 2 allocation(s).
  [root@quaco ~]#

With this we plug all leaks with "perf trace sleep 1".

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

## Which versions are affected by CVE-2023-53649?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-53649?

Apply the vendor's patch.

## Is CVE-2023-53649 being exploited?

There is no known exploitation of CVE-2023-53649 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-2023-53649 and fix it if it is affected.

What it is: CVE-2023-53649 is a medium-severity denial of service vulnerability in Linux kernel, published on 7 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-2023-53649 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-2023-53649/ (Markdown: https://insights.sbomify.com/CVE-2023-53649/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53649
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53649
- OSV: https://osv.dev/vulnerability/CVE-2023-53649

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53649/
Summaries are generated and may contain mistakes; the official description above is the record.