[PATCH v5] ping: Check return value of function 'ping_queue_rcv_skb'

[PATCH v5] ping: Check return value of function 'ping_queue_rcv_skb'

[Zheng Yongjun]

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>
---
v2:
- use rc as return value to make code look cleaner
v3:
- delete unnecessary braces {}
v4:
- put variable 'rc' declaration at the beginning of function
v5:
- don/t print unneed debuginfo in the right path
 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 1c9f71a37258..ea3ab58d1c38 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -954,6 +954,7 @@ 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 */
 
@@ -968,14 +969,15 @@ 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);
 
-- 
2.25.1

Re: [PATCH v5] ping: Check return value of function 'ping_queue_rcv_skb'

[David Ahern]

On 6/9/21 7:41 PM, Zheng Yongjun wrote:
> 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>
> ---
> v2:
> - use rc as return value to make code look cleaner
> v3:
> - delete unnecessary braces {}
> v4:
> - put variable 'rc' declaration at the beginning of function
> v5:
> - don/t print unneed debuginfo in the right path
>  net/ipv4/ping.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 

Reviewed-by: David Ahern <dsahern@kernel.org>