CVE-2026-23206 dpaa2-switch: prevent ZERO_SIZE_PTR dereference when num_ifs is zero
A null pointer dereference in the dpaa2-switch driver causes a kernel panic when the device reports zero interfaces, leading to denial of service.
- 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
What is CVE-2026-23206?
CVE-2026-23206 is a medium-severity vulnerability in Linux kernel, published on 14 Feb 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:
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.
Weakness: CWE-476
Which versions are affected by CVE-2026-23206?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-23206?
Apply the vendor's patch.
Is CVE-2026-23206 being exploited?
There is no known exploitation of CVE-2026-23206 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-77667, BELL-CVE-2026-23206, DEBIAN-CVE-2026-23206, GHSA-x2mr-3x78-f97g, ROOT-OS-DEBIAN-12-CVE-2026-23206, ROOT-OS-DEBIAN-13-CVE-2026-23206 and 3 more.