[PATCH 6.6 037/105] net: dlink: handle dma_map_single() failure properly

Greg Kroah-Hartman
2025-10-21T19:54:09Z

From: Yeounsu Moon <yyyynoom@gmail.com>

[ Upstream commit 65946eac6d888d50ae527c4e5c237dbe5cc3a2f2 ]

There is no error handling for `dma_map_single()` failures.

Add error handling by checking `dma_mapping_error()` and freeing
the `skb` using `dev_kfree_skb()` (process context) when it fails.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Yeounsu Moon <yyyynoom@gmail.com>
Tested-on: D-Link DGE-550T Rev-A3
Suggested-by: Simon Horman <horms@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/dlink/dl2k.c | 23 ++++++++++++++++-------
1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/dlink/dl2k.c b/drivers/net/ethernet/dlink/dl2k.c
index 1c3a5cf379cd0..72c97dcd0fee0 100644
--- a/drivers/net/ethernet/dlink/dl2k.c
+++ b/drivers/net/ethernet/dlink/dl2k.c
@@ -498,25 +498,34 @@ static int alloc_list(struct net_device *dev)
for (i = 0; i < RX_RING_SIZE; i++) {
/* Allocated fixed size of skbuff */
struct sk_buff *skb;
+ dma_addr_t addr;

skb = netdev_alloc_skb_ip_align(dev, np->rx_buf_sz);
np->rx_skbuff[i] = skb;
- if (!skb) {
- free_list(dev);
- return -ENOMEM;
- }
+ if (!skb)
+ goto err_free_list;
+
+ addr = dma_map_single(&np->pdev->dev, skb->data,
+ np->rx_buf_sz, DMA_FROM_DEVICE);
+ if (dma_mapping_error(&np->pdev->dev, addr))
+ goto err_kfree_skb;

np->rx_ring[i].next_desc = cpu_to_le64(np->rx_ring_dma +
((i + 1) % RX_RING_SIZE) *
sizeof(struct netdev_desc));
/* Rubicon now supports 40 bits of addressing space. */
- np->rx_ring[i].fraginfo =
- cpu_to_le64(dma_map_single(&np->pdev->dev, skb->data,
- np->rx_buf_sz, DMA_FROM_DEVICE));
+ np->rx_ring[i].fraginfo = cpu_to_le64(addr);
np->rx_ring[i].fraginfo |= cpu_to_le64((u64)np->rx_buf_sz << 48);
}

return 0;
+
+err_kfree_skb:
+ dev_kfree_skb(np->rx_skbuff[i]);
+ np->rx_skbuff[i] = NULL;
+err_free_list:
+ free_list(dev);
+ return -ENOMEM;
}

static void rio_hw_init(struct net_device *dev)
--
2.51.0