2021-06-10 01:44:30

by Zheng Yongjun

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

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 <[email protected]>
---
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

2021-06-11 03:40:19

by David Ahern

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

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 <[email protected]>
> ---
> 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 <[email protected]>