1 files changed, 67 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/xstatover.h b/sysdeps/unix/sysv/linux/xstatover.h
new file mode 100644
index 0000000000..20178114f9
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/xstatover.h
@@ -0,0 +1,67 @@
+/* Overflow tests for stat, statfs, and lseek functions.
+   Copyright (C) 2020 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <sys/stat.h>
+#include <sys/statfs.h>
+
+/* Test for overflows of structures where we ask the kernel to fill them
+   in with standard 64-bit syscalls but return them through APIs that
+   only expose the low 32 bits of some fields.  */
+
+static inline off_t lseek_overflow (loff_t res)
+{
+  off_t retval = (off_t) res;
+  if (retval == res)
+    return retval;
+
+  __set_errno (EOVERFLOW);
+  return (off_t) -1;
+}
+
+static inline int stat_overflow (struct stat *buf)
+{
+#if defined __INO_T_MATCHES_INO64_T || !STAT_IS_KERNEL_STAT
+  return 0;
+#else
+  if (buf->__st_ino_pad == 0 && buf->__st_size_pad == 0
+      && buf->__st_blocks_pad == 0)
+    return 0;
+
+  __set_errno (EOVERFLOW);
+  return -1;
+#endif
+}
+
+/* Note that f_files and f_ffree may validly be a sign-extended -1.  */
+static inline int statfs_overflow (struct statfs *buf)
+{
+#if __STATFS_MATCHES_STATFS64 || !STAT_IS_KERNEL_STAT
+  return 0;
+#else
+  if (buf->__f_blocks_pad == 0 && buf->__f_bfree_pad == 0
+      && buf->__f_bavail_pad == 0
+      && (buf->__f_files_pad == 0
+	  || (buf->f_files == -1U && buf->__f_files_pad == -1))
+      && (buf->__f_ffree_pad == 0
+	  || (buf->f_ffree == -1U && buf->__f_ffree_pad == -1)))
+    return 0;
+
+  __set_errno (EOVERFLOW);
+  return -1;
+#endif
+}