2021-06-07 08:59:25

by Zheng Yongjun

Subject: [PATCH] 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]>
---
net/ipv4/ping.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 1c9f71a37258..8e84cde95011 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -968,10 +968,11 @@ 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)) {
+ sock_put(sk);
+ return true;
+ }
sock_put(sk);
- return true;
}
pr_debug("no socket, dropping\n");

--
2.25.1

2021-06-07 16:34:31

by David Ahern

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

On 6/7/21 3:10 AM, 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]>
> ---
> net/ipv4/ping.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
> index 1c9f71a37258..8e84cde95011 100644
> --- a/net/ipv4/ping.c
> +++ b/net/ipv4/ping.c
> @@ -968,10 +968,11 @@ 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)) {
> + sock_put(sk);
> + return true;
> + }
> sock_put(sk);
> - return true;
> }
> pr_debug("no socket, dropping\n");
>
>

declare a default return variable:

bool rc = false;

set to to true if ping_queue_rcv_skb() fails and have one exit path with
one sock_put.

2021-06-08 01:49:49

by Zheng Yongjun

Subject: 答复: [PATCH] ping: Check return value of f unction 'ping_queue_rcv_skb'

Thank you for your suggestion, it will make the code look cleaner :)
I will send patch v2 soon.

-----邮件原件-----
发件人: David Ahern [mailto:[email protected]]
发送时间: 2021年6月8日 0:26
收件人: zhengyongjun <[email protected]>; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]
主题: Re: [PATCH] ping: Check return value of function 'ping_queue_rcv_skb'

On 6/7/21 3:10 AM, 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]>
> ---
> net/ipv4/ping.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index
> 1c9f71a37258..8e84cde95011 100644
> --- a/net/ipv4/ping.c
> +++ b/net/ipv4/ping.c
> @@ -968,10 +968,11 @@ 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)) {
> + sock_put(sk);
> + return true;
> + }
> sock_put(sk);
> - return true;
> }
> pr_debug("no socket, dropping\n");
>
>

declare a default return variable:

bool rc = false;

set to to true if ping_queue_rcv_skb() fails and have one exit path with one sock_put.