From: Abdun Nihaal <nihaal@cse.iitm.ac.in>
Date: Fri, 14 Nov 2025 09:45:26 +0000 (+0530)
Subject: wifi: rtl818x: Fix potential memory leaks in rtl8180_init_rx_ring()
X-Git-Tag: v6.19-rc1~170^2~33^2~10^2~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9b5b9c042b30befc5b37e4539ace95af70843473;p=thirdparty%2Fkernel%2Flinux.git

wifi: rtl818x: Fix potential memory leaks in rtl8180_init_rx_ring()

In rtl8180_init_rx_ring(), memory is allocated for skb packets and DMA
allocations in a loop. When an allocation fails, the previously
successful allocations are not freed on exit.

Fix that by jumping to err_free_rings label on error, which calls
rtl8180_free_rx_ring() to free the allocations. Remove the free of
rx_ring in rtl8180_init_rx_ring() error path, and set the freed
priv->rx_buf entry to null, to avoid double free.

Fixes: f653211197f3 ("Add rtl8180 wireless driver")
Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in>
Reviewed-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20251114094527.79842-1-nihaal@cse.iitm.ac.in
---

diff --git a/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c b/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c
index 2905baea62390..070c0431c4821 100644
--- a/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c
+++ b/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c
@@ -1023,9 +1023,6 @@ static int rtl8180_init_rx_ring(struct ieee80211_hw *dev)
 		dma_addr_t *mapping;
 		entry = priv->rx_ring + priv->rx_ring_sz*i;
 		if (!skb) {
-			dma_free_coherent(&priv->pdev->dev,
-					  priv->rx_ring_sz * 32,
-					  priv->rx_ring, priv->rx_ring_dma);
 			wiphy_err(dev->wiphy, "Cannot allocate RX skb\n");
 			return -ENOMEM;
 		}
@@ -1037,9 +1034,7 @@ static int rtl8180_init_rx_ring(struct ieee80211_hw *dev)
 
 		if (dma_mapping_error(&priv->pdev->dev, *mapping)) {
 			kfree_skb(skb);
-			dma_free_coherent(&priv->pdev->dev,
-					  priv->rx_ring_sz * 32,
-					  priv->rx_ring, priv->rx_ring_dma);
+			priv->rx_buf[i] = NULL;
 			wiphy_err(dev->wiphy, "Cannot map DMA for RX skb\n");
 			return -ENOMEM;
 		}
@@ -1130,7 +1125,7 @@ static int rtl8180_start(struct ieee80211_hw *dev)
 
 	ret = rtl8180_init_rx_ring(dev);
 	if (ret)
-		return ret;
+		goto err_free_rings;
 
 	for (i = 0; i < (dev->queues + 1); i++)
 		if ((ret = rtl8180_init_tx_ring(dev, i, 16)))