Re: [PATCH] net: ieee802154: fix error return code of dgram_sendmsg()

[Jia-Ju Bai <baijiaju1990@gmail.com>]

On 2021/3/8 18:19, Heiner Kallweit wrote:
> On 08.03.2021 10:31, Jia-Ju Bai wrote:
>> When sock_alloc_send_skb() returns NULL to skb, no error return code of
>> dgram_sendmsg() is assigned.
>> To fix this bug, err is assigned with -ENOMEM in this case.
>>
> Please stop sending such nonsense. Basically all such patches you
> sent so far are false positives. You have to start thinking,
> don't blindly trust your robot.
> In the case here the err variable is populated by sock_alloc_send_skb().

Ah, sorry, it is my fault :(
I did not notice that the err variable is populated by 
sock_alloc_send_skb().
I will think more carefully before sending patches.

By the way, I wonder how to report and discuss possible bugs that I am 
not quite sure of?
Some people told me that sending patches is better than reporting bugs 
via Bugzilla, so I write the patches of these possible bugs...
Do you have any advice?

Thanks a lot!


Best wishes,
Jia-Ju Bai
>
>> Fixes: 78f821b64826 ("ieee802154: socket: put handling into one file")
>> Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
>> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
>> ---
>>   net/ieee802154/socket.c | 4 +++-
>>   1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/net/ieee802154/socket.c b/net/ieee802154/socket.c
>> index a45a0401adc5..a750b37c7e73 100644
>> --- a/net/ieee802154/socket.c
>> +++ b/net/ieee802154/socket.c
>> @@ -642,8 +642,10 @@ static int dgram_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
>>   	skb = sock_alloc_send_skb(sk, hlen + tlen + size,
>>   				  msg->msg_flags & MSG_DONTWAIT,
>>   				  &err);
>> -	if (!skb)
>> +	if (!skb) {
>> +		err = -ENOMEM;
>>   		goto out_dev;
>> +	}
>>   
>>   	skb_reserve(skb, hlen);
>>   
>>