Bug 2439943 (CVE-2026-23206)

Summary: CVE-2026-23206 kernel: dpaa2-switch: prevent ZERO_SIZE_PTR dereference when num_ifs is zero
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedKeywords: Security
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OS: Linux   
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Description OSIDB Bzimport 2026-02-14 17:04:14 UTC 
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.
Comment 1 TEJ RATHI 2026-02-16 06:46:43 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026021438-CVE-2026-23206-ed03@gregkh/T