Commit 4678adf94da4 for kernel

commit 4678adf94da4a9e9683817b246b58ce15fb81782
Author: Daniel Borkmann <daniel@iogearbox.net>
Date:   Mon Oct 14 21:03:11 2024 +0200

    vmxnet3: Fix packet corruption in vmxnet3_xdp_xmit_frame

    Andrew and Nikolay reported connectivity issues with Cilium's service
    load-balancing in case of vmxnet3.

    If a BPF program for native XDP adds an encapsulation header such as
    IPIP and transmits the packet out the same interface, then in case
    of vmxnet3 a corrupted packet is being sent and subsequently dropped
    on the path.

    vmxnet3_xdp_xmit_frame() which is called e.g. via vmxnet3_run_xdp()
    through vmxnet3_xdp_xmit_back() calculates an incorrect DMA address:

      page = virt_to_page(xdpf->data);
      tbi->dma_addr = page_pool_get_dma_addr(page) +
                      VMXNET3_XDP_HEADROOM;
      dma_sync_single_for_device(&adapter->pdev->dev,
                                 tbi->dma_addr, buf_size,
                                 DMA_TO_DEVICE);

    The above assumes a fixed offset (VMXNET3_XDP_HEADROOM), but the XDP
    BPF program could have moved xdp->data. While the passed buf_size is
    correct (xdpf->len), the dma_addr needs to have a dynamic offset which
    can be calculated as xdpf->data - (void *)xdpf, that is, xdp->data -
    xdp->data_hard_start.

    Fixes: 54f00cce1178 ("vmxnet3: Add XDP support.")
    Reported-by: Andrew Sauber <andrew.sauber@isovalent.com>
    Reported-by: Nikolay Nikolaev <nikolay.nikolaev@isovalent.com>
    Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
    Tested-by: Nikolay Nikolaev <nikolay.nikolaev@isovalent.com>
    Acked-by: Anton Protopopov <aspsk@isovalent.com>
    Cc: William Tu <witu@nvidia.com>
    Cc: Ronak Doshi <ronak.doshi@broadcom.com>
    Link: https://patch.msgid.link/a0888656d7f09028f9984498cc698bb5364d89fc.1728931137.git.daniel@iogearbox.net
    Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/vmxnet3/vmxnet3_xdp.c b/drivers/net/vmxnet3/vmxnet3_xdp.c
index a6c787454a1a..1341374a4588 100644
--- a/drivers/net/vmxnet3/vmxnet3_xdp.c
+++ b/drivers/net/vmxnet3/vmxnet3_xdp.c
@@ -148,7 +148,7 @@ vmxnet3_xdp_xmit_frame(struct vmxnet3_adapter *adapter,
 	} else { /* XDP buffer from page pool */
 		page = virt_to_page(xdpf->data);
 		tbi->dma_addr = page_pool_get_dma_addr(page) +
-				VMXNET3_XDP_HEADROOM;
+				(xdpf->data - (void *)xdpf);
 		dma_sync_single_for_device(&adapter->pdev->dev,
 					   tbi->dma_addr, buf_size,
 					   DMA_TO_DEVICE);