# CVE-2026-99092: riscv: patch: fix handling of bpf-jit execmem addresses


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 26 Oct 2026
- **Updated:** 26 Oct 2026
- **Also known as:** BELL-CVE-2026-99092, DEBIAN-CVE-2026-99092, GHSA-m43v-97rg-mvc9, UBUNTU-CVE-2026-99092

## What is CVE-2026-99092?

CVE-2026-99092 is a vulnerability in Linux, published on 26 Oct 2026. 

### Official description

In the Linux kernel, the following vulnerability has been resolved:

riscv: patch: fix handling of bpf-jit execmem addresses

Commit 8718e5a3090b ("riscv: patch: skip fixmap mapping when kernel text
is already writable") gated the core_kernel_text() branch of patch_map()
on CONFIG_STRICT_KERNEL_RWX, and explicitly left the vmalloc branch
unchanged. That branch has a separate problem.

That branch only creates a temporary writable fixmap alias when
CONFIG_STRICT_MODULE_RWX is enabled, and otherwise assumes the target is
directly writable and returns the address unchanged. That assumption no
longer holds: bpf_prog_pack_alloc calls set_memory_rox() on every pack
unconditionally in alloc_new_pack(), independently of any
CONFIG_STRICT_*_RWX option, so BPF text in the vmalloc area is read-only
regardless of what CONFIG_STRICT_MODULE_RWX says.

With CONFIG_STRICT_MODULE_RWX=n, patch_map() returns the read-only
address directly, the subsequent copy_to_kernel_nofault() takes a
page fault and returns -EFAULT. bpf_arch_text_copy() turns that into
-EINVAL, which propagates through bpf_jit_binary_pack_finalize() to the
WARN_ON() in bpf_int_jit_compile() and leaves the program un-JITed.

Note that BPF cannot be fixed the way kprobes was in
commit bdc46e507b59 ("riscv: mm: make EXECMEM_KPROBES writable without
CONFIG_STRICT_MODULE_RWX"). EXECMEM_BPF is already PAGE_KERNEL, i.e.
writable at allocation time; the read-only mapping is established
afterwards by generic code in alloc_new_pack(), which arch code cannot
influence. The only place this can be handled is patch_map().

This is the same problem that was fixed on arm64 by commit b1480ed230ac
("arm64: patching: fix handling of execmem addresses"), and the fix is
the same: CONFIG_EXECMEM is what actually tracks whether the vmalloc
area can hold executable memory that needs a temporary alias to be
written. CONFIG_BPF_JIT, CONFIG_KPROBES and CONFIG_MODULES all select
it.

Note that this is not limited to CONFIG_MODULES=n. Unlike arm64, riscv
selects CONFIG_ARCH_OPTIONAL_KERNEL_RWX, so CONFIG_STRICT_MODULE_RWX can
be disabled with CONFIG_MODULES=y as well, and the bug is reachable in
that configuration too.

The !CONFIG_MMU build is unaffected: it has its own __patch_insn_set()
and __patch_insn_write() implementations and never calls patch_map().

## Which versions are affected by CVE-2026-99092?


## How do I fix CVE-2026-99092?

Upgrade to a fixed version.

## Is CVE-2026-99092 being exploited?

There is no known exploitation of CVE-2026-99092 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-99092 and fix it if it is affected.

What it is: CVE-2026-99092 is a vulnerability in Linux, published on 26 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-99092 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-2026-99092/ (Markdown: https://insights.sbomify.com/CVE-2026-99092/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-99092
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-99092
- OSV: https://osv.dev/vulnerability/CVE-2026-99092

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-99092/
Summaries are generated and may contain mistakes; the official description above is the record.