# CVE-2026-98058: bpf: Mark syscall helpers as sleepable

> A local attacker can trigger a kernel crash by invoking sleepable BPF helpers from atomic contexts, requiring kernel patching.

- **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-104553, BELL-CVE-2026-98058, DEBIAN-CVE-2026-98058, GHSA-24c8-ppg7-5393, UBUNTU-CVE-2026-98058

## What is CVE-2026-98058?

CVE-2026-98058 is a denial of service 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:

bpf: Mark syscall helpers as sleepable

bpf_sys_bpf() executes the bpf(2) syscall body, which can take mutexes,
allocate with GFP_KERNEL, and wait for an RCU grace period.
bpf_sys_close() reaches close_fd() and filp_close(), which can sleep as
well.

Both helpers are limited to BPF_PROG_TYPE_SYSCALL, whose main program is
sleepable. That does not make every callback sleepable: a syscall program
can register a bpf_timer callback, and the verifier checks that callback
in a non-sleepable context while retaining the syscall helper set.

Without .might_sleep on the prototypes, such a callback can invoke
bpf_sys_bpf() from hrtimer softirq context and trigger a
scheduling-while-atomic failure. bpf_sys_close() is exposed through the
same missing context check.

Set .might_sleep on both prototypes so the existing helper-context check
rejects them from timer callbacks and other atomic regions. Calls from the
sleepable main body remain valid.

## Which versions are affected by CVE-2026-98058?


## How do I fix CVE-2026-98058?

Apply the vendor's patch.

## Is CVE-2026-98058 being exploited?

There is no known exploitation of CVE-2026-98058 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98058 and fix it if it is affected.

What it is: CVE-2026-98058 is a denial of service 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-2026-98058 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-2026-98058/ (Markdown: https://insights.sbomify.com/CVE-2026-98058/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98058
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98058
- OSV: https://osv.dev/vulnerability/CVE-2026-98058

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98058/
Summaries are generated and may contain mistakes; the official description above is the record.