From d9670f5e77e56c98595eec1ff3fb3dc2a2dc0d55 Mon Sep 17 00:00:00 2001 From: Lv Yunlong Date: Sun, 28 Mar 2021 00:50:08 -0700 Subject: [PATCH] drivers/net/wan/hdlc_fr: Fix a double free in pvc_xmit [ Upstream commit 1b479fb801602b22512f53c19b1f93a4fc5d5d9d ] In pvc_xmit, if __skb_pad(skb, pad, false) failed, it will free the skb in the first time and goto drop. But the same skb is freed by kfree_skb(skb) in the second time in drop. Maintaining the original function unchanged, my patch adds a new label out to avoid the double free if __skb_pad() failed. Fixes: f5083d0cee08a ("drivers/net/wan/hdlc_fr: Improvements to the code of pvc_xmit") Signed-off-by: Lv Yunlong Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/wan/hdlc_fr.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/wan/hdlc_fr.c b/drivers/net/wan/hdlc_fr.c index 409e5a7..857912a 100644 --- a/drivers/net/wan/hdlc_fr.c +++ b/drivers/net/wan/hdlc_fr.c @@ -415,7 +415,7 @@ static netdev_tx_t pvc_xmit(struct sk_buff *skb, struct net_device *dev) if (pad > 0) { /* Pad the frame with zeros */ if (__skb_pad(skb, pad, false)) - goto drop; + goto out; skb_put(skb, pad); } } @@ -448,8 +448,9 @@ static netdev_tx_t pvc_xmit(struct sk_buff *skb, struct net_device *dev) return NETDEV_TX_OK; drop: - dev->stats.tx_dropped++; kfree_skb(skb); +out: + dev->stats.tx_dropped++; return NETDEV_TX_OK; } -- 2.7.4