On Tue, Apr 25, 2017 at 12:55 PM, Honggang LI <honli@xxxxxxxxxx> wrote: > From: Honggang Li <honli@xxxxxxxxxx> > > Minimal hard_header_len set by bond_compute_features is ETH_HLEN, which > is smaller than IPOIB_HARD_LEN. ipoib_hard_header should check the > size of headroom to avoid skb_under_panic. sounds terrible, ipoib bonding is supported since ~2007, thanks for reporting on that. > [ 122.871493] ipoib_hard_header: skb->head= ffff8808179d9400, skb->data= ffff8808179d9420, skb_headroom= 0x20 > [ 123.055400] bond0: Releasing backup interface mthca_ib1 > [ 123.560529] bond_compute_features:1112 bond0 bond_dev->hard_header_len = 14 > [ 123.568822] CPU: 0 PID: 12336 Comm: ifdown-ib Not tainted 4.9.0-debug #1 did you generate this trace by calling dump_stack or this is existing kernel code. > Fixes: fc791b633515 ('IB/ipoib: move back IB LL address into the hard header') this is more of WA to avoid some crash or failure but not fixing the actual problem Erez, can you comment? Or. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html