Fixed Seg fault in PMAP_CALLIT code (bz1264351)

Signed-off-by: Steve Dickson <steved@redhat.com>

rpcbind-0.2.3-pmap_callit.diff

@@ -0,0 +1,77 @@
+commit d5dace219953c45d26ae42db238052b68540649a
+Author: Olaf Kirch <okir@suse.de>
+Date:   Fri Oct 30 10:18:20 2015 -0400
+
+    Fix memory corruption in PMAP_CALLIT code
+    
+     - A PMAP_CALLIT call comes in on IPv4 UDP
+     - rpcbind duplicates the caller's address to a netbuf and stores it in
+       FINFO[0].caller_addr. caller_addr->buf now points to a memory region A
+       with a size of 16 bytes
+     - rpcbind forwards the call to the local service, receives a reply
+     - when processing the reply, it does this in xprt_set_caller:
+        xprt->xp_rtaddr = *FINFO[0].caller_addr
+       It sends out the reply, and then frees the netbuf caller_addr and
+       caller_addr.buf.
+       However, it does not clear xp_rtaddr, so xp_rtaddr.buf now refers
+       to memory region A, which is free.
+     - When the next call comes in on the UDP/IPv4 socket, svc_dg_recv will
+       be called, which will set xp_rtaddr to the client's address.
+       It will reuse the buffer inside xp_rtaddr, ie it will write a
+       sockaddr_in to region A
+    
+    Some time down the road, an incoming TCP connection is accepted,
+    allocating a fresh SVCXPRT. The memory region A is inside the
+    new SVCXPRT
+    
+     - While processing the TCP call, another UDP call comes in, again
+       overwriting region A with the client's address
+     - TCP client closes connection. In svc_destroy, we now trip over
+       the garbage left in region A
+    
+    We ran into the case where a commercial scanner was triggering
+    occasional rpcbind segfaults. The core file that was captured showed
+    a corrupted xprt->xp_netid pointer that was really a sockaddr_in.
+    
+    Signed-off-by: Olaf Kirch <okir@suse.de>
+    Signed-off-by: Steve Dickson <steved@redhat.com>
+
+diff --git a/src/rpcb_svc_com.c b/src/rpcb_svc_com.c
+index ff9ce6b..4ae93f1 100644
+--- a/src/rpcb_svc_com.c
++++ b/src/rpcb_svc_com.c
+@@ -1183,12 +1183,33 @@ check_rmtcalls(struct pollfd *pfds, int nfds)
+ 	return (ncallbacks_found);
+ }
+ 
++/*
++ * This is really a helper function defined in libtirpc, 
++ * but unfortunately, it hasn't been exported yet.
++ */
++static struct netbuf *
++__rpc_set_netbuf(struct netbuf *nb, const void *ptr, size_t len)
++{
++	if (nb->len != len) {
++		if (nb->len)
++			mem_free(nb->buf, nb->len);
++		nb->buf = mem_alloc(len);
++		if (nb->buf == NULL)
++			return NULL;
++
++		nb->maxlen = nb->len = len;
++	}
++	memcpy(nb->buf, ptr, len);
++	return nb;
++}
++
+ static void
+ xprt_set_caller(SVCXPRT *xprt, struct finfo *fi)
+ {
++	const struct netbuf *caller = fi->caller_addr;
+ 	u_int32_t *xidp;
+ 
+-	*(svc_getrpccaller(xprt)) = *(fi->caller_addr);
++	__rpc_set_netbuf(svc_getrpccaller(xprt), caller->buf, caller->len);
+ 	xidp = __rpcb_get_dg_xidp(xprt);
+ 	*xidp = fi->caller_xid;
+ }

rpcbind.spec

@@ -1,6 +1,6 @@
 Name:           rpcbind
 Version:        0.2.3
-Release:        0.3%{?dist}
+Release:        0.4%{?dist}
 Summary:        Universal Addresses to RPC Program Number Mapper
 Group:          System Environment/Daemons
 License:        BSD
@@ -21,6 +21,8 @@ Requires(post): chkconfig systemd
 Requires(preun): systemd
 Requires(postun): systemd coreutils
 
+Patch001: rpcbind-0.2.3-pmap_callit.diff
+
 Provides: portmap = %{version}-%{release}
 Obsoletes: portmap <= 4.0-65.3
 
@@ -32,6 +34,8 @@ RPC calls on a server on that machine.
 %prep
 %setup -q
 
+%patch001 -p1
+
 %build
 %ifarch s390 s390x
 PIE="-fPIE"
@@ -121,6 +125,9 @@ fi
 %{_unitdir}/rpcbind.socket
 
 %changelog
+* Mon Nov  2 2015 Steve Dickson <steved@redhat.com> - 0.2.3-0.4
+- Fixed Seg fault in PMAP_CALLIT code (bz1264351)
+
 * Sun Nov 01 2015 Kalev Lember <klember@redhat.com> - 0.2.3-0.3
 - Rebuilt for libtirpc soname bump