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 <f10b09ef687f> ("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 < 224 bytes. Also call vlan_features_check() to ensure proper handling of VLAN packets, particularly QinQ (802.1ad) configurations where the hardware parser may not support certain offload features. Validated using iptables to force small MSS values. Without the fix, the adapter freezes. With the fix, packets are segmented in software and transmission succeeds. Comprehensive regression testing completedd (MSS tests, performance, stability).
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
8641dd85799f85bef5f0d1f87356aaa12cb2195e to < 86fc64584811d43c9ccd74447de58620189d8b77affected8641dd85799f85bef5f0d1f87356aaa12cb2195e to < 9a5e984d7af910e46dcbed3ce77873e000a4f77daffected8641dd85799f85bef5f0d1f87356aaa12cb2195e to < 1cdf5dbcec988d06f5f720bdf89e91073f77fa10affected8641dd85799f85bef5f0d1f87356aaa12cb2195e to < 82bc89fbb82d9396fb4eaee8720ea85e2e787957affected8641dd85799f85bef5f0d1f87356aaa12cb2195e to < db8012c631cb845e9ae2b4b531e17d86c9519755affected8641dd85799f85bef5f0d1f87356aaa12cb2195e to < c1f261863e65b508f37416dfbc5c5d911c9b9233affected8641dd85799f85bef5f0d1f87356aaa12cb2195e to < 3af24f0c4c31f18a4a2d927990759194832bb6e9affected8641dd85799f85bef5f0d1f87356aaa12cb2195e to < cc427d24ac6442ffdeafd157a63c7c5b73ed4de4affected
Linux Linux
Default version status: affected
4.2affected0 to < 4.2unaffected5.10.258 to ≤ 5.10.*unaffected5.15.209 to ≤ 5.15.*unaffected6.1.175 to ≤ 6.1.*unaffected6.6.140 to ≤ 6.6.*unaffected6.12.88 to ≤ 6.12.*unaffected6.18.30 to ≤ 6.18.*unaffected7.0.7 to ≤ 7.0.*unaffected7.1 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/86fc64584811d43c9ccd74447de58620189d8b77 ↗
- https://git.kernel.org/stable/c/9a5e984d7af910e46dcbed3ce77873e000a4f77d ↗
- https://git.kernel.org/stable/c/1cdf5dbcec988d06f5f720bdf89e91073f77fa10 ↗
- https://git.kernel.org/stable/c/82bc89fbb82d9396fb4eaee8720ea85e2e787957 ↗
- https://git.kernel.org/stable/c/db8012c631cb845e9ae2b4b531e17d86c9519755 ↗
- https://git.kernel.org/stable/c/c1f261863e65b508f37416dfbc5c5d911c9b9233 ↗
- https://git.kernel.org/stable/c/3af24f0c4c31f18a4a2d927990759194832bb6e9 ↗
- https://git.kernel.org/stable/c/cc427d24ac6442ffdeafd157a63c7c5b73ed4de4 ↗