[PATCH AUTOSEL 5.5 27/66] net: atlantic: fix potential error handling

[Sasha Levin]

From: Pavel Belous <pbelous@xxxxxxxxxxx>

[ Upstream commit 380ec5b9af7f0d57dbf6ac067fd9f33cff2fef71 ]

Code inspection found that in case of mapping error we do return current
'ret' value. But beside error, it is used to count number of descriptors
allocated for the packet. In that case map_skb function could return '1'.

Changing it to return zero (number of mapped descriptors for skb)

Fixes: 018423e90bee ("net: ethernet: aquantia: Add ring support code")
Signed-off-by: Pavel Belous <pbelous@xxxxxxxxxxx>
Signed-off-by: Igor Russkikh <irusskikh@xxxxxxxxxxx>
Signed-off-by: Dmitry Bogdanov <dbogdanov@xxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ethernet/aquantia/atlantic/aq_nic.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/aquantia/atlantic/aq_nic.c b/drivers/net/ethernet/aquantia/atlantic/aq_nic.c
index 263beea1859c1..e95f6a6bef733 100644
--- a/drivers/net/ethernet/aquantia/atlantic/aq_nic.c
+++ b/drivers/net/ethernet/aquantia/atlantic/aq_nic.c
@@ -533,8 +533,10 @@ unsigned int aq_nic_map_skb(struct aq_nic_s *self, struct sk_buff *skb,
 				     dx_buff->len,
 				     DMA_TO_DEVICE);
 
-	if (unlikely(dma_mapping_error(aq_nic_get_dev(self), dx_buff->pa)))
+	if (unlikely(dma_mapping_error(aq_nic_get_dev(self), dx_buff->pa))) {
+		ret = 0;
 		goto exit;
+	}
 
 	first = dx_buff;
 	dx_buff->len_pkt = skb->len;
-- 
2.20.1