Resolves: bz 1690364

rng-tools.spec

@@ -10,6 +10,8 @@ URL:            https://github.com/nhorman/rng-tools
 Source0:        https://github.com/nhorman/rng-tools/archive/rng-tools-%{version}.tar.gz
 Source1:        rngd.service
 
+Patch0:	rngd-shutdown.patch
+
 # https://sourceforge.net/p/gkernel/patches/111/
 
 BuildRequires: gcc make
@@ -68,6 +70,9 @@ install -Dt %{buildroot}%{_unitdir} -m0644 %{SOURCE1}
 %attr(0644,root,root)   %{_unitdir}/rngd.service
 
 %changelog
+* Fri May 24 2019 Neil Horman <nhorman@redhat.com> -6.7-2
+- Fix race in shutdown leading to hang (bz 1690364)
+
 * Thu Feb 14 2019 Neil Horman <nhorman@redhat.com> - 6.7-1
 - Update to latest upstream
 

rngd-shutdown.patch

@@ -0,0 +1,35 @@
+diff --git a/rngd_jitter.c b/rngd_jitter.c
+index 23d96b3..43a13e0 100644
+--- a/rngd_jitter.c
++++ b/rngd_jitter.c
+@@ -473,26 +473,22 @@ void close_jitter_entropy_source(struct rng *ent_src)
+ 	for (i=0; i < num_threads; i++)
+ 		tdata[i].active = 0;
+ 
+-	flags = fcntl(pipefds[1], F_GETFL, 0);
+-	flags |= O_NONBLOCK;
+-	fcntl(pipefds[1], F_SETFL, &flags);
++	close(pipefds[1]);
+ 
+ 	/* And wait for completion of each thread */
+ 	for (i=0; i < num_threads; i++) {
+ 		message(LOG_DAEMON|LOG_DEBUG, "Checking on done for thread %d\n", i);
+ 		while (!tdata[i].done)
++			pthread_kill(threads[i], SIGINT);
+ 			if(tdata[i].done) {
+ 				message(LOG_DAEMON|LOG_INFO, "Closing thread %d\n", tdata[i].core_id);
+ 				pthread_join(threads[i], NULL);
+ 				jent_entropy_collector_free(tdata[i].ec);
+-			} else {
+-				read(pipefds[0], tmpbuf, 1024);
++			} else 
+ 				sched_yield();
+-			}
+ 	}
+ 
+-	close(pipefds[2]);
+-	close(pipefds[1]);
++	close(pipefds[0]);
+ 	free(tdata);
+ 	free(threads);
+ 	return;