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| author | Daniel Borkmann <daniel@iogearbox.net> | 2024-10-14 21:03:11 +0200 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2024-10-17 11:27:17 +0200 |
| commit | 4678adf94da4a9e9683817b246b58ce15fb81782 (patch) | |
| tree | 9e593d4d5a605ea3a2eea8565cf81ae7a139625e | |
| parent | 11d06f0aaef89f4cad68b92510bd9decff2d7b87 (diff) | |
| download | lwn-4678adf94da4a9e9683817b246b58ce15fb81782.tar.gz lwn-4678adf94da4a9e9683817b246b58ce15fb81782.zip | |
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>
| -rw-r--r-- | drivers/net/vmxnet3/vmxnet3_xdp.c | 2 |
1 files changed, 1 insertions, 1 deletions
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); |