Hi Florian,
On Fri, Sep 2, 2016 at 2:59 PM, Florian Westphal <f...@strlen.de> wrote:
> f...@ikuai8.com <f...@ikuai8.com> wrote:
>> From: Gao Feng <f...@ikuai8.com>
>>
>> When memory is exhausted, nfct_seqadj_ext_add may fail to add the seqadj
>> extension. But the function nf_ct_seqadj_init doesn't check if get valid
>> seqadj pointer by the nfct_seqadj, while other functions perform the
>> sanity check.
>>
>> So the system would be panic when nfct_seqadj_ext_add failed.
>>
>> Signed-off-by: Gao Feng <f...@ikuai8.com>
>
>> diff --git a/net/netfilter/nf_conntrack_seqadj.c
>> b/net/netfilter/nf_conntrack_seqadj.c
>> index dff0f0c..2c8e201 100644
>> --- a/net/netfilter/nf_conntrack_seqadj.c
>> +++ b/net/netfilter/nf_conntrack_seqadj.c
>> @@ -16,9 +16,14 @@ int nf_ct_seqadj_init(struct nf_conn *ct, enum
>> ip_conntrack_info ctinfo,
>> if (off == 0)
>> return 0;
>>
>> + seqadj = nfct_seqadj(ct);
>> + if (unlikely(!seqadj)) {
>> + WARN_ONCE(1, "Missing nfct_seqadj_ext_add() setup call\n");
>> + return 0;
>> + }
>> +
>
> Not sure this WARN() is really needed, I would remove it (since its most
> likely only missing due to memory shortage).
>
> Other than that, this looks good.
>
I prefer to keep the warning, although it only happens caused by mem
shortage now.
But it would give the accurate description, if the nfct_seqadj_ext_add
was lost when new features were depending on synadj.
Best Regards
Feng
