On Tue, 2013-07-23 at 19:06 +0300, Dan Carpenter wrote:
> Hello Trond Myklebust,
>
> This is a semi-automatic email about new static checker warnings.
>
> The patch b4a2cf76ab7c: "NFSv4: Fix a regression against the FreeBSD
> server" from Jul 17, 2013, leads to the following Smatch complaint:
>
> fs/nfs/nfs4xdr.c:1103 encode_attrs()
> error: we previously assumed 'label' could be null (see line 1059)
>
> fs/nfs/nfs4xdr.c
> 1058 }
> 1059 if (label) {
> ^^^^^
> New check.
>
> 1060 len += 4 + 4 + 4 + (XDR_QUADLEN(label->len) << 2);
> 1061 bmval[2] |= FATTR4_WORD2_SECURITY_LABEL;
> 1062 }
> 1063
> 1064 if (bmval[2] != 0)
> 1065 bmval_len = 3;
> 1066 else if (bmval[1] != 0)
> 1067 bmval_len = 2;
> 1068 else
> 1069 bmval_len = 1;
> 1070
>
> [snip]
>
> 1094 if (bmval[1] & FATTR4_WORD1_TIME_MODIFY_SET) {
> 1095 if (iap->ia_valid & ATTR_MTIME_SET) {
> 1096 *p++ = cpu_to_be32(NFS4_SET_TO_CLIENT_TIME);
> 1097 p = xdr_encode_hyper(p, (s64)iap->ia_mtime.tv_sec);
> 1098 *p++ = cpu_to_be32(iap->ia_mtime.tv_nsec);
> 1099 } else
> 1100 *p++ = cpu_to_be32(NFS4_SET_TO_SERVER_TIME);
> 1101 }
> 1102 if (bmval[2] & FATTR4_WORD2_SECURITY_LABEL) {
> 1103 *p++ = cpu_to_be32(label->lfs);
> ^^^^^^^^^^
> Old dereference.
>
> 1104 *p++ = cpu_to_be32(label->pi);
> 1105 *p++ = cpu_to_be32(label->len);
Hi Dan,
Maybe I need another coffee, but right now I don't see what the problem
is. We only set FATTR4_WORD2_SECURITY_LABEL if the check that label !=
NULL passes. What am I missing?
--
Trond Myklebust
Linux NFS client maintainer
NetApp
Trond.Myklebust@xxxxxxxxxx
www.netapp.com
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