open_init_pty: restore stdin/stdout to blocking upon exit
At exit, restore stdin and stdout to blocking.
Test: run_init id && run_init id
Test: open_init_pty bash -c 'echo hello; exec >&- 2>&- <&-; sleep 1;'
Fixes: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=863187
Fixes: https://bugs.gentoo.org/show_bug.cgi?id=621062
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
diff --git a/policycoreutils/run_init/open_init_pty.c b/policycoreutils/run_init/open_init_pty.c
index 6e25ea3..150cb45 100644
--- a/policycoreutils/run_init/open_init_pty.c
+++ b/policycoreutils/run_init/open_init_pty.c
@@ -191,6 +191,28 @@
}
}
+static void setfd_block(int fd)
+{
+ int fsflags = fcntl(fd, F_GETFL);
+
+ if (fsflags < 0) {
+ fprintf(stderr, "fcntl(%d, F_GETFL): %s\n", fd, strerror(errno));
+ exit(EX_IOERR);
+ }
+
+ if (fcntl(fd, F_SETFL, fsflags & ~O_NONBLOCK) < 0) {
+ fprintf(stderr, "fcntl(%d, F_SETFL, ... & ~O_NONBLOCK): %s\n", fd, strerror(errno));
+ exit(EX_IOERR);
+ }
+}
+
+static void setfd_atexit(void)
+{
+ setfd_block(STDIN_FILENO);
+ setfd_block(STDOUT_FILENO);
+ return;
+}
+
static void sigchld_handler(int asig __attribute__ ((unused)))
{
}
@@ -280,6 +302,10 @@
setfd_nonblock(pty_master);
setfd_nonblock(STDIN_FILENO);
setfd_nonblock(STDOUT_FILENO);
+ if (atexit(setfd_atexit) < 0) {
+ perror("atexit()");
+ exit(EXIT_FAILURE);
+ }
if (isatty(STDIN_FILENO)) {
if (tty_semi_raw(STDIN_FILENO) < 0) {
