At 2018-04-17 05:18:25, "Eric Dumazet" wrote:
>
>
>On 04/16/2018 09:58 AM, David Miller wrote:
>> From: gfree.w...@vip.163.com
>> Date: Mon, 16 Apr 2018 10:16:45 +0800
>>
>>> From: Gao Feng
>>>
>>> It would allocate memory in this function when the cork->opt is NULL. But
>>> the memory isn't freed if failed in the latter rt check, and return error
>>> directly. It causes the memleak if its caller is ip_make_skb which also
>>> doesn't free the cork->opt when meet a error.
>>>
>>> Now move the rt check ahead to avoid the memleak.
>>>
>>> Signed-off-by: Gao Feng
>>
>> Looks good, applied and queued up for -stable.
>>
>> I guess in the other code paths, ip_flush_pending_frames() or similar
>> would clean up the in-sock cork information.
>>
>
>I am not sure ip_make_skb() can be called with a NULL rt.
>
>Patch makes no harm, but does not seem to fix a bug.
>
Thanks Eric.
I just look up current all callers of ip_make_skb and ip_append_data, they check
if the rt is valid ahead. So current codes won't pass one NULL rt to
ip_setup_cork indeed.
Then this patch is just as an enhancement, not a fix.
As the programming rule, the function should free the mem which is allocated by
itself when
it failed.
Best Regards
Feng
