CVE-2026-46273 – ibmveth: Disable GSO for packets with small MSS

CVE ID :CVE-2026-46273

Published : June 3, 2026, 6:16 p.m. | 16 minutes ago

Description :In the Linux kernel, the following vulnerability has been resolved:

ibmveth: Disable GSO for packets with small MSS

Some physical adapters on Power systems do not support segmentation
offload when the MSS is less than 224 bytes. Attempting to send such
packets causes the adapter to freeze, stopping all traffic until
manually reset.

Implement ndo_features_check to disable GSO for packets with small MSS
values. The network stack will perform software segmentation instead.

The 224-byte minimum matches ibmvnic
commit (“ibmvnic: Enforce stronger sanity checks
on GSO packets”)
which uses the same physical adapters in SEA configurations.

The issue occurs specifically when the hardware attempts to perform
segmentation (gso_segs > 1) with a small MSS. Single-segment GSO packets
(gso_segs == 1) do not trigger the problematic LSO code path and are
transmitted normally without segmentation.

Add an ndo_features_check callback to disable GSO when MSS
Severity: 0.0 | NA

Visit the link for more details, such as CVSS details, affected products, timeline, and more…