[PATCH 5.13 502/800] mt76: testmode: remove undefined behaviour in mt76_testmode_alloc_skb

[Greg Kroah-Hartman]

From: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>

[ Upstream commit 223cea6d3c974acd393bfac2d168b2945a6cf1e5 ]

Get rid of an undefined behaviour in mt76_testmode_alloc_skb routine
allocating skb frames

Fixes: 2601dda8faa76 ("mt76: testmode: add support to send larger packet")
Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/wireless/mediatek/mt76/testmode.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/testmode.c b/drivers/net/wireless/mediatek/mt76/testmode.c
index f40387a866ee..f614c887f323 100644
--- a/drivers/net/wireless/mediatek/mt76/testmode.c
+++ b/drivers/net/wireless/mediatek/mt76/testmode.c
@@ -168,12 +168,8 @@ int mt76_testmode_alloc_skb(struct mt76_phy *phy, u32 len)
 		head->len += frag->len;
 		head->data_len += frag->len;
 
-		if (*frag_tail) {
-			(*frag_tail)->next = frag;
-			frag_tail = &frag;
-		} else {
-			*frag_tail = frag;
-		}
+		*frag_tail = frag;
+		frag_tail = &(*frag_tail)->next;
 	}
 
 	mt76_testmode_free_skb(phy);
-- 
2.30.2