libtirpc: disallow calling auth_refresh from clnt_call with RPCSEC_GSSlibtirpc-1-3-2-rc1

Disallow calling auth_refresh from clnt_{dg,vc}_call if the client is
using RPCSEC_GSS.  Doing so can recurse back into clnt_{dg,vc}_call,
where we'll self-deadlock waiting on the condition variable.

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

3 files changed, 23 insertions, 0 deletions

diff --git a/src/auth_gss.c b/src/auth_gss.c
index d871672..e317664 100644
--- a/src/auth_gss.c
+++ b/src/auth_gss.c
@@ -982,3 +982,9 @@ rpc_gss_max_data_length(AUTH *auth, int maxlen)
 	rpc_gss_clear_error();
 	return result;
 }
+
+bool_t
+is_authgss_client(CLIENT *clnt)
+{
+	return (clnt->cl_auth->ah_ops == &authgss_ops);
+}
diff --git a/src/clnt_dg.c b/src/clnt_dg.c
index abc09f1..e1255de 100644
--- a/src/clnt_dg.c
+++ b/src/clnt_dg.c
@@ -61,6 +61,9 @@
 #include <sys/uio.h>
 #endif
 
+#ifdef HAVE_RPCSEC_GSS
+#include <rpc/auth_gss.h>
+#endif
 
 #define MAX_DEFAULT_FDS                 20000
 
@@ -334,6 +337,11 @@ clnt_dg_call(cl, proc, xargs, argsp, xresults, resultsp, utimeout)
 		salen = cu->cu_rlen;
 	}
 
+#ifdef HAVE_RPCSEC_GSS
+	if (is_authgss_client(cl))
+		nrefreshes = 0;
+#endif
+
 	/* Clean up in case the last call ended in a longjmp(3) call. */
 call_again:
 	xdrs = &(cu->cu_outxdrs);
diff --git a/src/clnt_vc.c b/src/clnt_vc.c
index 6f7f7da..a07e297 100644
--- a/src/clnt_vc.c
+++ b/src/clnt_vc.c
@@ -69,6 +69,10 @@
 #include "rpc_com.h"
 #include "clnt_fd_locks.h"
 
+#ifdef HAVE_RPCSEC_GSS
+#include <rpc/auth_gss.h>
+#endif
+
 #define MCALL_MSG_SIZE 24
 
 #define CMGROUP_MAX    16
@@ -363,6 +367,11 @@ clnt_vc_call(cl, proc, xdr_args, args_ptr, xdr_results, results_ptr, timeout)
 	    (xdr_results == NULL && timeout.tv_sec == 0
 	    && timeout.tv_usec == 0) ? FALSE : TRUE;
 
+#ifdef HAVE_RPCSEC_GSS
+	if (is_authgss_client(cl))
+		refreshes = 0;
+#endif
+
 call_again:
 	xdrs->x_op = XDR_ENCODE;
 	ct->ct_error.re_status = RPC_SUCCESS;