Merge pull request #8083 from shawnl/close-ssh

sd-bus: cleanup ssh sessions (Closes: #8076)

src/basic/process-util.c

@@ -806,6 +806,13 @@ void sigkill_waitp(pid_t *pid) {
         sigkill_wait(*pid);
 }
 
+void sigterm_wait(pid_t pid) {
+        assert(pid > 1);
+
+        if (kill_and_sigcont(pid, SIGTERM) > 0)
+                (void) wait_for_terminate(pid, NULL);
+}
+
 int kill_and_sigcont(pid_t pid, int sig) {
         int r;
 

src/basic/process-util.h

@@ -76,6 +76,7 @@ int wait_for_terminate_with_timeout(pid_t pid, usec_t timeout);
 
 void sigkill_wait(pid_t pid);
 void sigkill_waitp(pid_t *pid);
+void sigterm_wait(pid_t pid);
 
 int kill_and_sigcont(pid_t pid, int sig);
 

src/libsystemd/sd-bus/bus-internal.h

@@ -296,6 +296,7 @@ struct sd_bus {
         unsigned n_memfd_cache;
 
         pid_t original_pid;
+        pid_t busexec_pid;
 
         sd_event_source *input_io_event_source;
         sd_event_source *output_io_event_source;

src/libsystemd/sd-bus/bus-socket.c

@@ -937,18 +937,18 @@ int bus_socket_connect(sd_bus *b) {
 
 int bus_socket_exec(sd_bus *b) {
         int s[2], r;
-        pid_t pid;
 
         assert(b);
         assert(b->input_fd < 0);
         assert(b->output_fd < 0);
         assert(b->exec_path);
+        assert(b->busexec_pid == 0);
 
         r = socketpair(AF_UNIX, SOCK_STREAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, s);
         if (r < 0)
                 return -errno;
 
-        r = safe_fork_full("(sd-busexec)", s+1, 1, FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS, &pid);
+        r = safe_fork_full("(sd-busexec)", s+1, 1, FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS, &b->busexec_pid);
         if (r < 0) {
                 safe_close_pair(s);
                 return r;

src/libsystemd/sd-bus/sd-bus.c

@@ -22,8 +22,10 @@
 #include <netdb.h>
 #include <poll.h>
 #include <pthread.h>
+#include <signal.h>
 #include <stdlib.h>
 #include <sys/mman.h>
+#include <sys/wait.h>
 #include <unistd.h>
 
 #include "sd-bus.h"
@@ -1095,6 +1097,13 @@ static int bus_parse_next_address(sd_bus *b) {
         return 1;
 }
 
+static void bus_kill_exec(sd_bus *bus) {
+        if (pid_is_valid(bus->busexec_pid) > 0) {
+                sigterm_wait(bus->busexec_pid);
+                bus->busexec_pid = 0;
+        }
+}
+
 static int bus_start_address(sd_bus *b) {
         int r;
 
@@ -1104,6 +1113,8 @@ static int bus_start_address(sd_bus *b) {
                 bus_close_io_fds(b);
                 bus_close_inotify_fd(b);
 
+                bus_kill_exec(b);
+
                 /* If you provide multiple different bus-addresses, we
                  * try all of them in order and use the first one that
                  * succeeds. */
@@ -1507,6 +1518,9 @@ _public_ void sd_bus_close(sd_bus *bus) {
         if (bus_pid_changed(bus))
                 return;
 
+        /* Don't leave ssh hanging around */
+        bus_kill_exec(bus);
+
         bus_set_state(bus, BUS_CLOSED);
 
         sd_bus_detach_event(bus);
@@ -1524,6 +1538,9 @@ _public_ sd_bus* sd_bus_flush_close_unref(sd_bus *bus) {
         if (!bus)
                 return NULL;
 
+        /* Have to do this before flush() to prevent hang */
+        bus_kill_exec(bus);
+
         sd_bus_flush(bus);
         sd_bus_close(bus);
 

src/machine/machinectl.c

@@ -1724,6 +1724,8 @@ static int rename_image(int argc, char *argv[], void *userdata) {
         sd_bus *bus = userdata;
         int r;
 
+        assert(bus);
+
         polkit_agent_open_if_enabled(arg_transport, arg_ask_password);
 
         r = sd_bus_call_method(
@@ -1749,6 +1751,8 @@ static int clone_image(int argc, char *argv[], void *userdata) {
         sd_bus *bus = userdata;
         int r;
 
+        assert(bus);
+
         polkit_agent_open_if_enabled(arg_transport, arg_ask_password);
 
         r = sd_bus_message_new_method_call(
@@ -1778,6 +1782,8 @@ static int read_only_image(int argc, char *argv[], void *userdata) {
         sd_bus *bus = userdata;
         int b = true, r;
 
+        assert(bus);
+
         if (argc > 2) {
                 b = parse_boolean(argv[2]);
                 if (b < 0) {