# CVE-2026-97614: net: dsa: tag_brcm: legacy FCS: request needed tailroom

> A local attacker can trigger a slab-out-of-bounds read in the Linux kernel's Broadcom DSA tagger, potentially causing a crash or leaking memory.

- **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:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-97614, DEBIAN-CVE-2026-97614, GHSA-3px2-442r-8h6r, UBUNTU-CVE-2026-97614

## What is CVE-2026-97614?

CVE-2026-97614 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:

net: dsa: tag_brcm: legacy FCS: request needed tailroom

The legacy FCS tagger calculates the CRC over skb->len bytes starting at
skb->data. When a nonlinear skb reaches the tagger, this reads past the
linear head into unrelated slab memory.

The tagger appends an Ethernet FCS but does not declare that tailroom. As a
result, DSA leaves NETIF_F_SG and NETIF_F_FRAGLIST enabled on the user
port, and nonlinear skbs can reach the CRC calculation.

Declare the required tailroom. DSA will then clear those features and the
networking core will linearize skbs before the tagger runs.

A KASAN-enabled dsa_loop test using this tagger reports:

  BUG: KASAN: slab-out-of-bounds in crc32_le
  Read of size 1 at addr ffff8880397086c0 by task exp/135

  Call Trace:
   crc32_le (lib/crc/crc32-main.c:38)
   brcm_leg_fcs_tag_xmit (net/dsa/tag_brcm.c:343)
   dsa_user_xmit (net/dsa/user.c:942)
   dev_hard_start_xmit (net/core/dev.c:3937)
   __dev_queue_xmit (net/core/dev.c:4926)
   packet_sendmsg (net/packet/af_packet.c:3110)
   __sys_sendto (net/socket.c:2281)

  The buggy address belongs to the object at ffff888039708400
   which belongs to the cache skbuff_small_head of size 704
  The buggy address is located 0 bytes to the right of
   allocated 704-byte region [ffff888039708400, ffff8880397086c0)

## Which versions are affected by CVE-2026-97614?


## How do I fix CVE-2026-97614?

Apply the vendor's patch.

## Is CVE-2026-97614 being exploited?

There is no known exploitation of CVE-2026-97614 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97614 and fix it if it is affected.

What it is: CVE-2026-97614 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-2026-97614 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-2026-97614/ (Markdown: https://insights.sbomify.com/CVE-2026-97614/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97614
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97614
- OSV: https://osv.dev/vulnerability/CVE-2026-97614

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97614/
Summaries are generated and may contain mistakes; the official description above is the record.