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authorFlorian Weimer <fweimer@redhat.com>2016-02-19 14:49:38 +0100
committerFlorian Weimer <fweimer@redhat.com>2016-02-19 14:49:38 +0100
commit6793dd51d8e7d4f3408c183c6f7dc86acd7f1330 (patch)
tree7d8f6b314549b47a510f3cfb387743f8fd4e7001 /posix/spawn_valid_fd.c
parentff889b196575c2fbf6aa7130abb1ec862714ea4e (diff)
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Improve file descriptor checks for posix_spawn actions [BZ #19505]
Diffstat (limited to 'posix/spawn_valid_fd.c')
-rw-r--r--posix/spawn_valid_fd.c31
1 files changed, 31 insertions, 0 deletions
diff --git a/posix/spawn_valid_fd.c b/posix/spawn_valid_fd.c
new file mode 100644
index 0000000000..c199750557
--- /dev/null
+++ b/posix/spawn_valid_fd.c
@@ -0,0 +1,31 @@
+/* File descriptor validity check for posix_spawn file actions.
+   Copyright (C) 2000-2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include "spawn_int.h"
+
+#include <unistd.h>
+
+bool
+internal_function
+__spawn_valid_fd (int fd)
+{
+  long maxfd = __sysconf (_SC_OPEN_MAX);
+  return __glibc_likely (fd >= 0)
+    && (__glibc_unlikely (maxfd < 0) /* No limit set.  */
+	|| __glibc_likely (fd < maxfd));
+}