SUNRPC: Introduce new xdr_stream-based encoders to rpcb_clnt.c
Replace the open-coded encode logic for rpcbind arguments with an
xdr_stream-based implementation, similar to what NFSv4 uses, to
better protect against buffer overflows.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index 1fb1c07..823d20d 100644
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -708,6 +708,30 @@
return 0;
}
+static int rpcb_enc_mapping(struct rpc_rqst *req, __be32 *p,
+ const struct rpcbind_args *rpcb)
+{
+ struct rpc_task *task = req->rq_task;
+ struct xdr_stream xdr;
+
+ dprintk("RPC: %5u encoding PMAP_%s call (%u, %u, %d, %u)\n",
+ task->tk_pid, task->tk_msg.rpc_proc->p_name,
+ rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
+
+ xdr_init_encode(&xdr, &req->rq_snd_buf, p);
+
+ p = xdr_reserve_space(&xdr, sizeof(__be32) * RPCB_mappingargs_sz);
+ if (unlikely(p == NULL))
+ return -EIO;
+
+ *p++ = htonl(rpcb->r_prog);
+ *p++ = htonl(rpcb->r_vers);
+ *p++ = htonl(rpcb->r_prot);
+ *p = htonl(rpcb->r_port);
+
+ return 0;
+}
+
static int rpcb_decode_getport(struct rpc_rqst *req, __be32 *p,
unsigned short *portp)
{
@@ -746,6 +770,56 @@
return 0;
}
+static int encode_rpcb_string(struct xdr_stream *xdr, const char *string,
+ const u32 maxstrlen)
+{
+ u32 len;
+ __be32 *p;
+
+ if (unlikely(string == NULL))
+ return -EIO;
+ len = strlen(string);
+ if (unlikely(len > maxstrlen))
+ return -EIO;
+
+ p = xdr_reserve_space(xdr, sizeof(__be32) + len);
+ if (unlikely(p == NULL))
+ return -EIO;
+ xdr_encode_opaque(p, string, len);
+
+ return 0;
+}
+
+static int rpcb_enc_getaddr(struct rpc_rqst *req, __be32 *p,
+ const struct rpcbind_args *rpcb)
+{
+ struct rpc_task *task = req->rq_task;
+ struct xdr_stream xdr;
+
+ dprintk("RPC: %5u encoding RPCB_%s call (%u, %u, '%s', '%s')\n",
+ task->tk_pid, task->tk_msg.rpc_proc->p_name,
+ rpcb->r_prog, rpcb->r_vers,
+ rpcb->r_netid, rpcb->r_addr);
+
+ xdr_init_encode(&xdr, &req->rq_snd_buf, p);
+
+ p = xdr_reserve_space(&xdr,
+ sizeof(__be32) * (RPCB_program_sz + RPCB_version_sz));
+ if (unlikely(p == NULL))
+ return -EIO;
+ *p++ = htonl(rpcb->r_prog);
+ *p = htonl(rpcb->r_vers);
+
+ if (encode_rpcb_string(&xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN))
+ return -EIO;
+ if (encode_rpcb_string(&xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN))
+ return -EIO;
+ if (encode_rpcb_string(&xdr, rpcb->r_owner, RPCB_MAXOWNERLEN))
+ return -EIO;
+
+ return 0;
+}
+
static int rpcb_decode_getaddr(struct rpc_rqst *req, __be32 *p,
unsigned short *portp)
{
@@ -812,7 +886,7 @@
#define PROC(proc, argtype, restype) \
[RPCBPROC_##proc] = { \
.p_proc = RPCBPROC_##proc, \
- .p_encode = (kxdrproc_t) rpcb_encode_##argtype, \
+ .p_encode = (kxdrproc_t) rpcb_enc_##argtype, \
.p_decode = (kxdrproc_t) rpcb_decode_##restype, \
.p_arglen = RPCB_##argtype##args_sz, \
.p_replen = RPCB_##restype##res_sz, \