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	Fix PSE port assignment for 3rd GMAC on MT7988 and make sure dma_addr is always initialized to prevent potentially accessing uninitialized stack memory in the error path. Signed-off-by: Daniel Golle <daniel@makrotopia.org>
		
			
				
	
	
		
			45 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			45 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
From e10a35abb3da12b812cfb6fc6137926a0c81e39a Mon Sep 17 00:00:00 2001
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From: Daniel Golle <daniel@makrotopia.org>
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Date: Sun, 10 Sep 2023 22:40:30 +0100
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Subject: [PATCH] net: ethernet: mtk_eth_soc: fix uninitialized variable
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Variable dma_addr in function mtk_poll_rx can be uninitialized on
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some of the error paths. In practise this doesn't matter, even random
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data present in uninitialized stack memory can safely be used in the
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way it happens in the error path.
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However, in order to make Smatch happy make sure the variable is
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always initialized.
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Signed-off-by: Daniel Golle <daniel@makrotopia.org>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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---
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 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 5 +++--
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 1 file changed, 3 insertions(+), 2 deletions(-)
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--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
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+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
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@@ -1989,11 +1989,11 @@ static int mtk_poll_rx(struct napi_struc
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 	u8 *data, *new_data;
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 	struct mtk_rx_dma_v2 *rxd, trxd;
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 	int done = 0, bytes = 0;
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+	dma_addr_t dma_addr = DMA_MAPPING_ERROR;
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 	while (done < budget) {
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 		unsigned int pktlen, *rxdcsum;
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 		struct net_device *netdev;
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-		dma_addr_t dma_addr;
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 		u32 hash, reason;
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 		int mac = 0;
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@@ -2170,7 +2170,8 @@ release_desc:
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 		else
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 			rxd->rxd2 = RX_DMA_PREP_PLEN0(ring->buf_size);
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-		if (MTK_HAS_CAPS(eth->soc->caps, MTK_36BIT_DMA))
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+		if (MTK_HAS_CAPS(eth->soc->caps, MTK_36BIT_DMA) &&
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+		    likely(dma_addr != DMA_MAPPING_ERROR))
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 			rxd->rxd2 |= RX_DMA_PREP_ADDR64(dma_addr);
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 		ring->calc_idx = idx;
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