NFSv4: Fix the underestimation of delegation XDR space reservation
[pandora-kernel.git] / fs / nfs / nfs4xdr.c
index e6161b2..b6dbf70 100644 (file)
@@ -149,8 +149,10 @@ static int nfs4_stat_to_errno(int);
                                open_owner_id_maxsz + \
                                encode_opentype_maxsz + \
                                encode_claim_null_maxsz)
+#define decode_space_limit_maxsz       (3)
 #define decode_ace_maxsz       (3 + nfs4_owner_maxsz)
 #define decode_delegation_maxsz        (1 + decode_stateid_maxsz + 1 + \
+                               decode_space_limit_maxsz + \
                                decode_ace_maxsz)
 #define decode_change_info_maxsz       (5)
 #define decode_open_maxsz      (op_decode_hdr_maxsz + \
@@ -2517,11 +2519,12 @@ static void nfs4_xdr_enc_getacl(struct rpc_rqst *req, struct xdr_stream *xdr,
        encode_compound_hdr(xdr, req, &hdr);
        encode_sequence(xdr, &args->seq_args, &hdr);
        encode_putfh(xdr, args->fh, &hdr);
-       replen = hdr.replen + op_decode_hdr_maxsz + nfs4_fattr_bitmap_maxsz + 1;
+       replen = hdr.replen + op_decode_hdr_maxsz + 1;
        encode_getattr_two(xdr, FATTR4_WORD0_ACL, 0, &hdr);
 
        xdr_inline_pages(&req->rq_rcv_buf, replen << 2,
                args->acl_pages, args->acl_pgbase, args->acl_len);
+
        encode_nops(&hdr);
 }
 
@@ -3055,7 +3058,8 @@ out_overflow:
        return -EIO;
 }
 
-static int decode_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
+static bool __decode_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected,
+               int *nfs_retval)
 {
        __be32 *p;
        uint32_t opnum;
@@ -3065,19 +3069,32 @@ static int decode_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
        if (unlikely(!p))
                goto out_overflow;
        opnum = be32_to_cpup(p++);
-       if (opnum != expected) {
-               dprintk("nfs: Server returned operation"
-                       " %d but we issued a request for %d\n",
-                               opnum, expected);
-               return -EIO;
-       }
+       if (unlikely(opnum != expected))
+               goto out_bad_operation;
        nfserr = be32_to_cpup(p);
-       if (nfserr != NFS_OK)
-               return nfs4_stat_to_errno(nfserr);
-       return 0;
+       if (nfserr == NFS_OK)
+               *nfs_retval = 0;
+       else
+               *nfs_retval = nfs4_stat_to_errno(nfserr);
+       return true;
+out_bad_operation:
+       dprintk("nfs: Server returned operation"
+               " %d but we issued a request for %d\n",
+                       opnum, expected);
+       *nfs_retval = -EREMOTEIO;
+       return false;
 out_overflow:
        print_overflow_msg(__func__, xdr);
-       return -EIO;
+       *nfs_retval = -EIO;
+       return false;
+}
+
+static int decode_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
+{
+       int retval;
+
+       __decode_op_hdr(xdr, expected, &retval);
+       return retval;
 }
 
 /* Dummy routine */
@@ -4743,11 +4760,12 @@ static int decode_open(struct xdr_stream *xdr, struct nfs_openres *res)
        uint32_t savewords, bmlen, i;
        int status;
 
-       status = decode_op_hdr(xdr, OP_OPEN);
-       if (status != -EIO)
-               nfs_increment_open_seqid(status, res->seqid);
-       if (!status)
-               status = decode_stateid(xdr, &res->stateid);
+       if (!__decode_op_hdr(xdr, OP_OPEN, &status))
+               return status;
+       nfs_increment_open_seqid(status, res->seqid);
+       if (status)
+               return status;
+       status = decode_stateid(xdr, &res->stateid);
        if (unlikely(status))
                return status;
 
@@ -4957,17 +4975,26 @@ decode_restorefh(struct xdr_stream *xdr)
 }
 
 static int decode_getacl(struct xdr_stream *xdr, struct rpc_rqst *req,
-               size_t *acl_len)
+                        struct nfs_getaclres *res)
 {
-       __be32 *savep;
+       __be32 *savep, *bm_p;
        uint32_t attrlen,
                 bitmap[3] = {0};
        struct kvec *iov = req->rq_rcv_buf.head;
        int status;
+       size_t page_len = xdr->buf->page_len;
 
-       *acl_len = 0;
+       res->acl_len = 0;
        if ((status = decode_op_hdr(xdr, OP_GETATTR)) != 0)
                goto out;
+
+       bm_p = xdr->p;
+       res->acl_data_offset = be32_to_cpup(bm_p) + 2;
+       res->acl_data_offset <<= 2;
+       /* Check if the acl data starts beyond the allocated buffer */
+       if (res->acl_data_offset > page_len)
+               return -ERANGE;
+
        if ((status = decode_attr_bitmap(xdr, bitmap)) != 0)
                goto out;
        if ((status = decode_attr_length(xdr, &attrlen, &savep)) != 0)
@@ -4977,20 +5004,28 @@ static int decode_getacl(struct xdr_stream *xdr, struct rpc_rqst *req,
                return -EIO;
        if (likely(bitmap[0] & FATTR4_WORD0_ACL)) {
                size_t hdrlen;
-               u32 recvd;
+
+               /* The bitmap (xdr len + bitmaps) and the attr xdr len words
+                * are stored with the acl data to handle the problem of
+                * variable length bitmaps.*/
+               xdr->p = bm_p;
 
                /* We ignore &savep and don't do consistency checks on
                 * the attr length.  Let userspace figure it out.... */
                hdrlen = (u8 *)xdr->p - (u8 *)iov->iov_base;
-               recvd = req->rq_rcv_buf.len - hdrlen;
-               if (attrlen > recvd) {
-                       dprintk("NFS: server cheating in getattr"
-                                       " acl reply: attrlen %u > recvd %u\n",
-                                       attrlen, recvd);
+               attrlen += res->acl_data_offset;
+               if (attrlen > page_len) {
+                       if (res->acl_flags & NFS4_ACL_LEN_REQUEST) {
+                               /* getxattr interface called with a NULL buf */
+                               res->acl_len = attrlen;
+                               goto out;
+                       }
+                       dprintk("NFS: acl reply: attrlen %u > page_len %zu\n",
+                                       attrlen, page_len);
                        return -EINVAL;
                }
                xdr_read_pages(xdr, attrlen);
-               *acl_len = attrlen;
+               res->acl_len = attrlen;
        } else
                status = -EOPNOTSUPP;
 
@@ -6019,6 +6054,10 @@ nfs4_xdr_dec_getacl(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
        struct compound_hdr hdr;
        int status;
 
+       if (res->acl_scratch != NULL) {
+               void *p = page_address(res->acl_scratch);
+               xdr_set_scratch_buffer(xdr, p, PAGE_SIZE);
+       }
        status = decode_compound_hdr(xdr, &hdr);
        if (status)
                goto out;
@@ -6028,7 +6067,7 @@ nfs4_xdr_dec_getacl(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
        status = decode_putfh(xdr);
        if (status)
                goto out;
-       status = decode_getacl(xdr, rqstp, &res->acl_len);
+       status = decode_getacl(xdr, rqstp, res);
 
 out:
        return status;
@@ -6091,7 +6130,8 @@ static int nfs4_xdr_dec_open(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
        status = decode_open(xdr, res);
        if (status)
                goto out;
-       if (decode_getfh(xdr, &res->fh) != 0)
+       status = decode_getfh(xdr, &res->fh);
+       if (status)
                goto out;
        if (decode_getfattr(xdr, res->f_attr, res->server,
                                !RPC_IS_ASYNC(rqstp->rq_task)) != 0)