Fix bug #9166 - Starting smbd or nmbd with stdin from /dev/null results in "EOF on stdin"

Only install the stdin handler if it's a pipe or fifo.

Signed-off-by: Jeremy Allison <jra@samba.org>

Reviewed-by: Andrew Bartlett <abartlet@samba.org>

4 files changed, 54 insertions, 6 deletions

diff --git a/source3/nmbd/nmbd.c b/source3/nmbd/nmbd.c
index 12afb00993..42e2b2f6ff 100644
--- a/source3/nmbd/nmbd.c
+++ b/source3/nmbd/nmbd.c
@@ -130,8 +130,20 @@ static bool nmbd_setup_stdin_handler(struct messaging_context *msg, bool foregro
 		/* if we are running in the foreground then look for
 		   EOF on stdin, and exit if it happens. This allows
 		   us to die if the parent process dies
+		   Only do this on a pipe or socket, no other device.
 		*/
-		tevent_add_fd(nmbd_event_context(), nmbd_event_context(), 0, TEVENT_FD_READ, nmbd_stdin_handler, msg);
+		struct stat st;
+		if (fstat(0, &st) != 0) {
+			return false;
+		}
+		if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode)) {
+			tevent_add_fd(nmbd_event_context(),
+				nmbd_event_context(),
+				0,
+				TEVENT_FD_READ,
+				nmbd_stdin_handler,
+				msg);
+		}
 	}
 
 	return true;
diff --git a/source3/smbd/server.c b/source3/smbd/server.c
index f07bd28fb4..d3cd33ec90 100644
--- a/source3/smbd/server.c
+++ b/source3/smbd/server.c
@@ -1558,8 +1558,20 @@ extern void build_options(bool screen);
 		/* if we are running in the foreground then look for
 		   EOF on stdin, and exit if it happens. This allows
 		   us to die if the parent process dies
+		   Only do this on a pipe or socket, no other device.
 		*/
-		tevent_add_fd(ev_ctx, parent, 0, TEVENT_FD_READ, smbd_stdin_handler, NULL);
+		struct stat st;
+		if (fstat(0, &st) != 0) {
+			return false;
+		}
+		if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode)) {
+			tevent_add_fd(ev_ctx,
+					parent,
+					0,
+					TEVENT_FD_READ,
+					smbd_stdin_handler,
+					NULL);
+		}
 	}
 
 	smbd_parent_loop(ev_ctx, parent);
diff --git a/source3/winbindd/winbindd.c b/source3/winbindd/winbindd.c
index 7a0700dffa..141ca5c7c5 100644
--- a/source3/winbindd/winbindd.c
+++ b/source3/winbindd/winbindd.c
@@ -308,6 +308,8 @@ bool winbindd_setup_stdin_handler(bool parent, bool foreground)
 	bool *is_parent;
 
 	if (foreground) {
+		struct stat st;
+
 		is_parent = talloc(winbind_event_context(), bool);
 		if (!is_parent) {
 			return false;
@@ -318,8 +320,19 @@ bool winbindd_setup_stdin_handler(bool parent, bool foreground)
 		/* if we are running in the foreground then look for
 		   EOF on stdin, and exit if it happens. This allows
 		   us to die if the parent process dies
+		   Only do this on a pipe or socket, no other device.
 		*/
-		tevent_add_fd(winbind_event_context(), is_parent, 0, TEVENT_FD_READ, winbindd_stdin_handler, is_parent);
+		if (fstat(0, &st) != 0) {
+			return false;
+		}
+		if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode)) {
+			tevent_add_fd(winbind_event_context(),
+					is_parent,
+					0,
+					TEVENT_FD_READ,
+					winbindd_stdin_handler,
+					is_parent);
+		}
 	}
 
 	return true;
diff --git a/source4/smbd/server.c b/source4/smbd/server.c
index 5fb252e93d..0ad3e6ba41 100644
--- a/source4/smbd/server.c
+++ b/source4/smbd/server.c
@@ -301,6 +301,7 @@ static int binary_smbd_main(const char *binary_name, int argc, const char *argv[
 	NTSTATUS status;
 	const char *model = "standard";
 	int max_runtime = 0;
+	struct stat st;
 	enum {
 		OPT_DAEMON = 1000,
 		OPT_INTERACTIVE,
@@ -439,9 +440,19 @@ static int binary_smbd_main(const char *binary_name, int argc, const char *argv[
 #ifdef SIGTTIN
 	signal(SIGTTIN, SIG_IGN);
 #endif
-	tevent_add_fd(event_ctx, event_ctx, 0, stdin_event_flags,
-		      server_stdin_handler,
-		      discard_const(binary_name));
+
+	if (fstat(0, &st) != 0) {
+		exit(1);
+	}
+
+	if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode)) {
+		tevent_add_fd(event_ctx,
+				event_ctx,
+				0,
+				stdin_event_flags,
+				server_stdin_handler,
+				discard_const(binary_name));
+	}
 
 	if (max_runtime) {
 		DEBUG(0,("Called with maxruntime %d - current ts %llu\n",