# CVE-2026-98365: RDMA/rxe: Fix integer overflow in mr_check_range() leading to OOB access

> A remote attacker can trigger an integer overflow in the Linux kernel RDMA module, causing an out-of-bounds access that leads to a kernel crash or potential code execution.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-106473, BELL-CVE-2026-98365, DEBIAN-CVE-2026-98365, GHSA-3p8h-wx5x-6qq3, UBUNTU-CVE-2026-98365

## What is CVE-2026-98365?

CVE-2026-98365 is a critical vulnerability in Linux, published on 6 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

RDMA/rxe: Fix integer overflow in mr_check_range() leading to OOB access

mr_check_range() validates that [iova, iova+length) falls within the
registered MR range using wraparound-prone arithmetic:

    if (iova < mr->ibmr.iova ||
        iova + length > mr->ibmr.iova + mr->ibmr.length)

A remote peer can craft an RDMA-Write/Read RETH so that iova + length
wraps to 0 (e.g. iova=0xfffffffffffffff8, length=8), bypassing the
check. rxe_mr_iova_to_index() then computes a huge index (int idx, only
guarded by WARN_ON) and rxe_mr_copy_xarray() dereferences
mr->page_info[huge], causing an out-of-bounds read/write and a kernel
oops that is triggerable by an unauthenticated remote peer.

Rewrite the check in overflow-safe form; the first two clauses guarantee
that the subsequent subtractions do not underflow:

    if (iova < mr->ibmr.iova ||
        length > mr->ibmr.length ||
        iova - mr->ibmr.iova > mr->ibmr.length - length)

With the fix, mr_check_range() returns -EINVAL for the crafted iova and
the responder reports REMOTE_ACCESS_ERROR instead of triggering the OOB.

## Which versions are affected by CVE-2026-98365?


## How do I fix CVE-2026-98365?

Apply the vendor's patch.

## Is CVE-2026-98365 being exploited?

There is no known exploitation of CVE-2026-98365 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98365 and fix it if it is affected.

What it is: CVE-2026-98365 is a critical vulnerability in Linux, published on 6 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-98365 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-2026-98365/ (Markdown: https://insights.sbomify.com/CVE-2026-98365/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98365
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98365
- OSV: https://osv.dev/vulnerability/CVE-2026-98365

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98365/
Summaries are generated and may contain mistakes; the official description above is the record.