Re: [PATCH][net-next] nexthop: fix incorrect allocation failure on nhg->spare

From: Nikolay Aleksandrov
Date: Thu May 28 2020 - 11:55:23 EST


On 28/05/2020 18:53, Colin Ian King wrote:
> On 28/05/2020 15:55, Nikolay Aleksandrov wrote:
>> On 28/05/2020 17:53, Nikolay Aleksandrov wrote:
>>> On 28/05/2020 17:51, Colin King wrote:
>>>> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>>>>
>>>> The allocation failure check for nhg->spare is currently checking
>>>> the pointer nhg rather than nhg->spare which is never false. Fix
>>>> this by checking nhg->spare instead.
>>>>
>>>> Addresses-Coverity: ("Logically dead code")
>>>> Fixes: 430a049190de ("nexthop: Add support for nexthop groups")
>>>> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>>>> ---
>>>> net/ipv4/nexthop.c | 2 +-
>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
>>>> index ebafa5ed91ac..97423d6f2de9 100644
>>>> --- a/net/ipv4/nexthop.c
>>>> +++ b/net/ipv4/nexthop.c
>>>> @@ -1185,7 +1185,7 @@ static struct nexthop *nexthop_create_group(struct net *net,
>>>>
>>>> /* spare group used for removals */
>>>> nhg->spare = nexthop_grp_alloc(num_nh);
>>>> - if (!nhg) {
>>>> + if (!nhg->spare) {
>>>> kfree(nhg);
>>>> kfree(nh);
>>>> return NULL;
>>>>
>>>
>>> Good catch, embarrassing copy paste error :-/
>>> Acked-by: Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx>
>>>
>>
>> Wait - that should be targeted at -net, that's where the fixes went.
>> And the fixes tag is wrong, nhg->spare was very recently added by:
>> commit 90f33bffa382
>> Author: Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx>
>> Date: Tue May 26 12:56:15 2020 -0600
>>
>> nexthops: don't modify published nexthop groups
>>
>
> Do you require me to fix this up and re-send?
>
> Colin
>

Up to you, it will go to the same stable releases as that fix used the same
Fixes tag, so it's really not an issue.