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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Zheng Yongjun <zhengyongjun3@huawei.com>,
        "David S . Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 59/71] ping: Check return value of function 'ping_queue_rcv_skb'
Date:   Mon, 28 Jun 2021 10:39:51 -0400
Message-Id: <20210628144003.34260-60-sashal@kernel.org>
In-Reply-To: <20210628144003.34260-1-sashal@kernel.org>
References: <20210628144003.34260-1-sashal@kernel.org>
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From: Zheng Yongjun <zhengyongjun3@huawei.com>

[ Upstream commit 9d44fa3e50cc91691896934d106c86e4027e61ca ]

Function 'ping_queue_rcv_skb' not always return success, which will
also return fail. If not check the wrong return value of it, lead to function
`ping_rcv` return success.

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/ipv4/ping.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 4fda9abf38ee..dd4e46af1e53 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -976,6 +976,7 @@ bool ping_rcv(struct sk_buff *skb)
 	struct sock *sk;
 	struct net *net = dev_net(skb->dev);
 	struct icmphdr *icmph = icmp_hdr(skb);
+	bool rc = false;
 
 	/* We assume the packet has already been checked by icmp_rcv */
 
@@ -990,14 +991,15 @@ bool ping_rcv(struct sk_buff *skb)
 		struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 
 		pr_debug("rcv on socket %p\n", sk);
-		if (skb2)
-			ping_queue_rcv_skb(sk, skb2);
+		if (skb2 && !ping_queue_rcv_skb(sk, skb2))
+			rc = true;
 		sock_put(sk);
-		return true;
 	}
-	pr_debug("no socket, dropping\n");
 
-	return false;
+	if (!rc)
+		pr_debug("no socket, dropping\n");
+
+	return rc;
 }
 EXPORT_SYMBOL_GPL(ping_rcv);
 
-- 
2.30.2