# CVE-2026-97934: tracing: Fix memory corruption from a "STACKTRACE" histogram key

> A local attacker with tracing access can trigger memory corruption and kernel panic via a specific histogram key configuration.

- **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:** 25 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-104768, BELL-CVE-2026-97934, DEBIAN-CVE-2026-97934, GHSA-3wpw-vmp3-5ppq, UBUNTU-CVE-2026-97934

## What is CVE-2026-97934?

CVE-2026-97934 is a memory corruption vulnerability in Linux, published on 25 Sep 2026. 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:

tracing: Fix memory corruption from a "STACKTRACE" histogram key

"cpu", "CPU", "stacktrace" and "STACKTRACE" are generic fields, defined
with an offset and a size of zero so that the filter code can match them
by name. parse_field() maps them onto their common_* equivalents for
backward compatibility, but unlike the common_* names it hands the
placeholder back to the caller instead of NULL.

create_hist_field() takes a non-NULL field as a promise that the record
carries a stacktrace and picks HIST_FIELD_FN_STACK, so the __data_loc
word is read from offset 0, that is from common_type, and its low 16
bits are followed as an offset into the record. What is found there
becomes the length of an unbounded memcpy. Pick an event whose id is
small enough that the offset stays inside its own record and the length
is a kernel text address:

  # cd /sys/kernel/tracing
  # echo 'hist:keys=STACKTRACE' > events/ftrace/print/trigger
  # echo hello > trace_marker

  Oops: general protection fault, probably for non-canonical address
  RIP: 0010:rb_next+0x23/0x60
   </IRQ>
  RIP: 0010:memcpy+0xc/0x30
   event_hist_trigger+0x2e7/0x12c0
  Kernel panic - not syncing: Fatal exception in interrupt

Leave the field NULL, which is what the comment above the branch says
the code does and what common_stacktrace already does. FILTER_CPU and
FILTER_COMM are left alone, their create_hist_field() branches never
look at the field.

## Which versions are affected by CVE-2026-97934?


## How do I fix CVE-2026-97934?

Apply the vendor's patch.

## Is CVE-2026-97934 being exploited?

There is no known exploitation of CVE-2026-97934 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97934 and fix it if it is affected.

What it is: CVE-2026-97934 is a memory corruption vulnerability in Linux, published on 25 Sep 2026. 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-2026-97934 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-2026-97934/ (Markdown: https://insights.sbomify.com/CVE-2026-97934/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97934
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97934
- OSV: https://osv.dev/vulnerability/CVE-2026-97934

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97934/
Summaries are generated and may contain mistakes; the official description above is the record.