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-rw-r--r--src/misc/forkpty.c17
1 files changed, 15 insertions, 2 deletions
diff --git a/src/misc/forkpty.c b/src/misc/forkpty.c
index 0bbf2de2..07f8d01e 100644
--- a/src/misc/forkpty.c
+++ b/src/misc/forkpty.c
@@ -1,14 +1,25 @@
 #include <pty.h>
 #include <unistd.h>
 #include <sys/ioctl.h>
+#include <fcntl.h>
 
 int forkpty(int *m, char *name, const struct termios *tio, const struct winsize *ws)
 {
-	int s;
+	int s, t, i, istmp[3]={0};
 	pid_t pid;
 
 	if (openpty(m, &s, name, tio, ws) < 0) return -1;
-	pid = fork();
+
+	/* Ensure before forking that we don't exceed fd limit */
+	for (i=0; i<3; i++) {
+		if (fcntl(i, F_GETFL) < 0) {
+			t = fcntl(s, F_DUPFD, i);
+			if (t<0) break;
+			else if (t!=i) close(t);
+			else istmp[i] = 1;
+		}
+	}
+	pid = i==3 ? fork() : -1;
 	if (!pid) {
 		close(*m);
 		setsid();
@@ -19,6 +30,8 @@ int forkpty(int *m, char *name, const struct termios *tio, const struct winsize
 		if (s>2) close(s);
 		return 0;
 	}
+	for (i=0; i<3; i++)
+		if (istmp[i]) close(i);
 	close(s);
 	if (pid < 0) close(*m);
 	return pid;