[PATCH 6.6 590/638] vmxnet3: Fix missing reserved tailroom

From: Sasha Levin
Date: Mon Mar 25 2024 - 02:07:52 EST


From: William Tu <witu@xxxxxxxxxx>

[ Upstream commit e127ce7699c1e05279ee5ee61f00893e7bfa9671 ]

Use rbi->len instead of rcd->len for non-dataring packet.

Found issue:
XDP_WARN: xdp_update_frame_from_buff(line:278): Driver BUG: missing reserved tailroom
WARNING: CPU: 0 PID: 0 at net/core/xdp.c:586 xdp_warn+0xf/0x20
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W O 6.5.1 #1
RIP: 0010:xdp_warn+0xf/0x20
...
? xdp_warn+0xf/0x20
xdp_do_redirect+0x15f/0x1c0
vmxnet3_run_xdp+0x17a/0x400 [vmxnet3]
vmxnet3_process_xdp+0xe4/0x760 [vmxnet3]
? vmxnet3_tq_tx_complete.isra.0+0x21e/0x2c0 [vmxnet3]
vmxnet3_rq_rx_complete+0x7ad/0x1120 [vmxnet3]
vmxnet3_poll_rx_only+0x2d/0xa0 [vmxnet3]
__napi_poll+0x20/0x180
net_rx_action+0x177/0x390

Reported-by: Martin Zaharinov <micron10@xxxxxxxxx>
Tested-by: Martin Zaharinov <micron10@xxxxxxxxx>
Link: https://lore.kernel.org/netdev/74BF3CC8-2A3A-44FF-98C2-1E20F110A92E@xxxxxxxxx/
Fixes: 54f00cce1178 ("vmxnet3: Add XDP support.")
Signed-off-by: William Tu <witu@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240309183147.28222-1-witu@xxxxxxxxxx
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/vmxnet3/vmxnet3_xdp.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/vmxnet3/vmxnet3_xdp.c b/drivers/net/vmxnet3/vmxnet3_xdp.c
index 80ddaff759d47..a6c787454a1ae 100644
--- a/drivers/net/vmxnet3/vmxnet3_xdp.c
+++ b/drivers/net/vmxnet3/vmxnet3_xdp.c
@@ -382,12 +382,12 @@ vmxnet3_process_xdp(struct vmxnet3_adapter *adapter,
page = rbi->page;
dma_sync_single_for_cpu(&adapter->pdev->dev,
page_pool_get_dma_addr(page) +
- rq->page_pool->p.offset, rcd->len,
+ rq->page_pool->p.offset, rbi->len,
page_pool_get_dma_dir(rq->page_pool));

- xdp_init_buff(&xdp, rbi->len, &rq->xdp_rxq);
+ xdp_init_buff(&xdp, PAGE_SIZE, &rq->xdp_rxq);
xdp_prepare_buff(&xdp, page_address(page), rq->page_pool->p.offset,
- rcd->len, false);
+ rbi->len, false);
xdp_buff_clear_frags_flag(&xdp);

xdp_prog = rcu_dereference(rq->adapter->xdp_bpf_prog);
--
2.43.0