# CVE-2026-89864: scsi: qla2xxx: Bound i2c->length in I2C bsg handlers

> A local attacker with CAP_SYS_RAWIO can trigger a buffer overflow in the qla2xxx SCSI driver, leading to kernel memory corruption and potential privilege escalation.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-101558, BELL-CVE-2026-89864, DEBIAN-CVE-2026-89864, GHSA-vhpc-fmr8-vgcc, UBUNTU-CVE-2026-89864

## What is CVE-2026-89864?

CVE-2026-89864 is a memory corruption vulnerability in Linux, published on 16 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:

scsi: qla2xxx: Bound i2c->length in I2C bsg handlers

struct qla_i2c_access carries a 16-bit length field alongside a fixed
64-byte buffer:

	struct qla_i2c_access {
		uint16_t device, offset, option, length;
		uint8_t  buffer[0x40];
	} __packed;

qla2x00_write_i2c() and qla2x00_read_i2c() use the user-supplied
i2c->length without any bounds check. i2c is overlaid on a 256-byte
on-stack buffer and sfp is a 256-byte DMA-pool buffer, so a length up to
65535 overruns both:

  - write: memcpy(sfp, i2c->buffer, i2c->length) over-reads the stack and
    over-writes the sfp heap buffer, and qla2x00_write_sfp() then DMAs
    i2c->length bytes out of the 256-byte buffer.
  - read: qla2x00_read_sfp() DMAs i2c->length bytes into the 256-byte sfp,
    then memcpy(i2c->buffer, sfp, i2c->length) overflows the 64-byte
    buffer inside the on-stack array.

A caller holding CAP_SYS_RAWIO can use this to corrupt the heap and the
kernel stack. Reject requests whose length exceeds the buffer before any
copy or DMA transfer in both handlers.

## Which versions are affected by CVE-2026-89864?


## How do I fix CVE-2026-89864?

Apply the vendor's patch.

## Is CVE-2026-89864 being exploited?

There is no known exploitation of CVE-2026-89864 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89864 and fix it if it is affected.

What it is: CVE-2026-89864 is a memory corruption vulnerability in Linux, published on 16 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-2026-89864 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-2026-89864/ (Markdown: https://insights.sbomify.com/CVE-2026-89864/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89864
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89864
- OSV: https://osv.dev/vulnerability/CVE-2026-89864

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89864/
Summaries are generated and may contain mistakes; the official description above is the record.