On 16/02/13 17:30, J. Bruce Fields wrote:
> On Sat, Feb 16, 2013 at 03:35:26PM -0500, Steve Dickson wrote:
>> On 12/02/13 18:03, J. Bruce Fields wrote:
>>>> +static int decode_attr_security_label(struct xdr_stream *xdr, uint32_t *bitmap,
>>>>> + struct nfs4_label *label)
>>>>> +{
>>>>> + uint32_t pi = 0;
>>>>> + uint32_t lfs = 0;
>>>>> + __u32 len;
>>>>> + __be32 *p;
>>>>> + int status = 0;
>>>>> +
>>>>> + if (unlikely(bitmap[2] & (FATTR4_WORD2_SECURITY_LABEL - 1U)))
>>>>> + return -EIO;
>>>>> + if (likely(bitmap[2] & FATTR4_WORD2_SECURITY_LABEL)) {
>>>>> + p = xdr_inline_decode(xdr, 4);
>>>>> + if (unlikely(!p))
>>>>> + goto out_overflow;
>>>>> + lfs = be32_to_cpup(p++);
>>>>> + p = xdr_inline_decode(xdr, 4);
>>>>> + if (unlikely(!p))
>>>>> + goto out_overflow;
>>>>> + pi = be32_to_cpup(p++);
>>>>> + p = xdr_inline_decode(xdr, 4);
>>>>> + if (unlikely(!p))
>>>>> + goto out_overflow;
>>>>> + len = be32_to_cpup(p++);
>>>>> + p = xdr_inline_decode(xdr, len);
>>>>> + if (unlikely(!p))
>>>>> + goto out_overflow;
>>>>> + if (len < XDR_MAX_NETOBJ) {
>>>>> + if (label) {
>>>>> + nfs4_label_init(label);
>>>>> + if (label->len < len) {
>>> If I remember the earlier patch right, nfs4_label_init() just set
>>> label->len to NFS4_MAXLABELLEN.
>> Good good catch... XDR_MAX_NETOBJ should be NFS4_MAXLABELLEN.
>>
>>>
>>> Doesn't that overwrite the length that was passed into
>>> nfs4_get_security_label?
>> Yes... the len will be set to the actual size of the label which
>> will be less than NFS4_MAXLABELLEN. So I'm thinking this overwrite
>> of the is fine.
>>
>> This is the reason nfs4_label_init() resets len to NFS4_MAXLABELLEN
>
> OK, but then
> if (label->len < len)
> is equivalent to
> if (NFS4_MAXLABELLEN < len)
> Why are we checking len twice?
I see your point...
>
> You may want to just remove nfs4_label_init() entirely. This is the
> only caller, and it doesn't seem very useful.
Its a useful way to reset len back to NFS4_MAXLABELLEN as well as
lfs and pi back to zero...
steved.
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