Since v6.17, X550 adapters without VFs can crash the host on an MDD event, as reported by Melissa on netdev [0], by Viacheslav on intel-wired-lan [1], and by Proxmox VE users [2].
Patch 1 fixes the NULL pointer dereference, and the out-of-bounds vfinfo write for events on PF pools with SR-IOV enabled too. Patch 2 stops enabling MDD without VFs, which is how such setups get MDD events at all. Why the hardware flags PF queues is still unclear to me, all reports show tx:80000. For completness sake, on E610, the tx hang path in ixgbe_handle_mdd_event() looks like it can still reach vfinfo for pools without a VF if VT mode is enabled without VFs, e.g. with macvlan offload, that's not fixed here. Tested on a Supermicro H11DSi-NT with its onboard X550: without this series RDRXCTL.MDP_EN is set whenever the link is up, also without VFs or after removing them again. With it, MDD is only enabled while VFs exist. Patch 1 is not tested in-depth yet though, as I have no reproducer for the MDD events themselves, so any testing by the reporters would be more than welcome. [0] https://lore.kernel.org/netdev/bqzPMb-F5iRWe7S2DWkQDhsK8u9ZoIaK34sF2pHpAjP6WHFb70Weq3pc8ZIVUoIx2EbPHd6HLBzz1HHd3xb5rxRZ9F3w1L6TQAd87S18CPQ=@proton.me/ [1] https://lore.kernel.org/all/[email protected]/ [2] https://bugzilla.proxmox.com/show_bug.cgi?id=7874 Thomas Lamprecht (2): ixgbe: fix NULL pointer dereference on MDD event without VFs ixgbe: do not enable MDD without VFs drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 2 +- drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c | 16 +++++++++++----- 2 files changed, 12 insertions(+), 6 deletions(-) base-commit: 7704c4c5bb127673b4f0ead839919db573559e38 -- 2.47.3
