NULL Pointer Dereference Affecting linux-6.1 package, versions <6.1.164-1~deb11u1


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
0.11% (2nd percentile)

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  • Snyk IDSNYK-DEBIAN11-LINUX61-15654916
  • published16 Mar 2026
  • disclosed14 Feb 2026

Introduced: 14 Feb 2026

CVE-2026-23206  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

Upgrade Debian:11 linux-6.1 to version 6.1.164-1~deb11u1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream linux-6.1 package and not the linux-6.1 package as distributed by Debian. See How to fix? for Debian:11 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1