5 files changed, 39 insertions, 4 deletions
diff --git a/shell/ash.c b/shell/ash.c
index aee3d419c..efb4615db 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -5433,11 +5433,11 @@ redirect(union node *redir, int flags)
 			/* Careful to not accidentally "save"
 			 * to the same fd as right side fd in N>&M */
 			int minfd = right_fd < 10 ? 10 : right_fd + 1;
+#if defined(F_DUPFD_CLOEXEC)
+			i = fcntl(fd, F_DUPFD_CLOEXEC, minfd);
+#else
 			i = fcntl(fd, F_DUPFD, minfd);
-/* You'd expect copy to be CLOEXECed. Currently these extra "saved" fds
- * are closed in popredir() in the child, preventing them from leaking
- * into child. (popredir() also cleans up the mess in case of failures)
- */
+#endif
 			if (i == -1) {
 				i = errno;
 				if (i != EBADF) {
@@ -5452,6 +5452,9 @@ redirect(union node *redir, int flags)
  remember_to_close:
 				i = CLOSED;
 			} else { /* fd is open, save its copy */
+#if !defined(F_DUPFD_CLOEXEC)
+				fcntl(i, F_SETFD, FD_CLOEXEC);
+#endif
 				/* "exec fd>&-" should not close fds
 				 * which point to script file(s).
 				 * Force them to be restored afterwards */
diff --git a/shell/ash_test/ash-redir/redir_leak.right b/shell/ash_test/ash-redir/redir_leak.right
new file mode 100644
index 000000000..b1c48292b
--- /dev/null
+++ b/shell/ash_test/ash-redir/redir_leak.right
@@ -0,0 +1,6 @@
+4
+4
+4
+4
+4
+4
diff --git a/shell/ash_test/ash-redir/redir_leak.tests b/shell/ash_test/ash-redir/redir_leak.tests
new file mode 100755
index 000000000..c8a9c6343
--- /dev/null
+++ b/shell/ash_test/ash-redir/redir_leak.tests
@@ -0,0 +1,10 @@
+# Each of these should show only four lines:
+# fds 0,1,2 are stdio; fd 3 is open by opendir() in ls.
+# This test detects bugs where redirects leave stray open fds.
+
+ls -1 /proc/self/fd | wc -l
+ls -1 /proc/self/fd >/proc/self/fd/1 | wc -l
+ls -1 /proc/self/fd >/proc/self/fd/1 2>&1 | wc -l
+echo "`ls -1 /proc/self/fd `" | wc -l
+echo "`ls -1 /proc/self/fd >/proc/self/fd/1 `" | wc -l
+echo "`ls -1 /proc/self/fd >/proc/self/fd/1 2>&1 `" | wc -l
diff --git a/shell/hush_test/hush-redir/redir_leak.right b/shell/hush_test/hush-redir/redir_leak.right
new file mode 100644
index 000000000..b1c48292b
--- /dev/null
+++ b/shell/hush_test/hush-redir/redir_leak.right
@@ -0,0 +1,6 @@
+4
+4
+4
+4
+4
+4
diff --git a/shell/hush_test/hush-redir/redir_leak.tests b/shell/hush_test/hush-redir/redir_leak.tests
new file mode 100755
index 000000000..c8a9c6343
--- /dev/null
+++ b/shell/hush_test/hush-redir/redir_leak.tests
@@ -0,0 +1,10 @@
+# Each of these should show only four lines:
+# fds 0,1,2 are stdio; fd 3 is open by opendir() in ls.
+# This test detects bugs where redirects leave stray open fds.
+
+ls -1 /proc/self/fd | wc -l
+ls -1 /proc/self/fd >/proc/self/fd/1 | wc -l
+ls -1 /proc/self/fd >/proc/self/fd/1 2>&1 | wc -l
+echo "`ls -1 /proc/self/fd `" | wc -l
+echo "`ls -1 /proc/self/fd >/proc/self/fd/1 `" | wc -l
+echo "`ls -1 /proc/self/fd >/proc/self/fd/1 2>&1 `" | wc -l