Commit 0c5661ec authored Feb 23, 2018 by Emil Tantilov Committed by David S. Miller Feb 26, 2018

ixgbe: fix crash in build_skb Rx code path



Add check for build_skb enabled ring in ixgbe_dma_sync_frag().
In that case &skb_shinfo(skb)->frags[0] may not always be set which
can lead to a crash. Instead we derive the page offset from skb->data.

Fixes: 42073d91
("ixgbe: Have the CPU take ownership of the buffers sooner")
CC: stable <stable@vger.kernel.org>
Reported-by: Ambarish Soman <asoman@redhat.com>
Suggested-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 13a55372

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -1888,6 +1888,14 @@ static void ixgbe_dma_sync_frag(struct ixgbe_ring *rx_ring,
		ixgbe_rx_pg_size(rx_ring),
		DMA_FROM_DEVICE,
		IXGBE_RX_DMA_ATTR);
		} else if (ring_uses_build_skb(rx_ring)) {
		unsigned long offset = (unsigned long)(skb->data) & ~PAGE_MASK;

		dma_sync_single_range_for_cpu(rx_ring->dev,
		IXGBE_CB(skb)->dma,
		offset,
		skb_headlen(skb),
		DMA_FROM_DEVICE);
		} else {
		struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[0];