linux: open and openat ignore 'mode' with O_TMPFILE in flags

Both open and openat load their last argument 'mode' lazily, using
va_arg() only if O_CREAT is found in oflag. This is wrong, mode is also
necessary if O_TMPFILE is in oflag.

By chance on x86_64, the problem wasn't evident when using O_TMPFILE
with open, as the 3rd argument of open, even when not loaded with
va_arg, is left untouched in RDX, where the syscall expects it.

However, openat was not so lucky, and O_TMPFILE couldn't be used: mode
is the 4th argument, in RCX, but the syscall expects its 4th argument in
a different register than the glibc wrapper, in R10.

Introduce a macro __OPEN_NEEDS_MODE (oflag) to test if either O_CREAT or
O_TMPFILE is set in oflag.

Tested on Linux x86_64.

	[BZ #17523]
	* io/fcntl.h (__OPEN_NEEDS_MODE): New macro.
	* io/bits/fcntl2.h (open): Use it.
	(openat): Likewise.
	* io/open.c (__libc_open): Likewise.
	* io/open64.c (__libc_open64): Likewise.
	* io/open64_2.c (__open64_2): Likewise.
	* io/open_2.c (__open_2): Likewise.
	* io/openat.c (__openat): Likewise.
	* io/openat64.c (__openat64): Likewise.
	* io/openat64_2.c (__openat64_2): Likewise.
	* io/openat_2.c (__openat_2): Likewise.
	* sysdeps/mach/hurd/open.c (__libc_open): Likewise.
	* sysdeps/mach/hurd/openat.c (__openat): Likewise.
	* sysdeps/posix/open64.c (__libc_open64): Likewise.
	* sysdeps/unix/sysv/linux/dl-openat64.c (openat64): Likewise.
	* sysdeps/unix/sysv/linux/generic/open.c (__libc_open): Likewise.
	(__open_nocancel): Likewise.
	* sysdeps/unix/sysv/linux/generic/open64.c (__libc_open64): Likewise.
	* sysdeps/unix/sysv/linux/open64.c (__libc_open64): Likewise.
	* sysdeps/unix/sysv/linux/openat.c (__OPENAT): Likewise.

10 files changed, 37 insertions, 27 deletions

diff --git a/io/bits/fcntl2.h b/io/bits/fcntl2.h
index 745bb0b..2ac54b2 100644
--- a/io/bits/fcntl2.h
+++ b/io/bits/fcntl2.h
@@ -20,7 +20,7 @@
 # error "Never include <bits/fcntl2.h> directly; use <fcntl.h> instead."
 #endif
 
-/* Check that calls to open and openat with O_CREAT set have an
+/* Check that calls to open and openat with O_CREAT or O_TMPFILE set have an
    appropriate third/fourth parameter.  */
 #ifndef __USE_FILE_OFFSET64
 extern int __open_2 (const char *__path, int __oflag) __nonnull ((1));
@@ -35,7 +35,7 @@ extern int __REDIRECT (__open_alias, (const char *__path, int __oflag, ...),
 __errordecl (__open_too_many_args,
 	     "open can be called either with 2 or 3 arguments, not more");
 __errordecl (__open_missing_mode,
-	     "open with O_CREAT in second argument needs 3 arguments");
+	     "open with O_CREAT or O_TMPFILE in second argument needs 3 arguments");
 
 __fortify_function int
 open (const char *__path, int __oflag, ...)
@@ -45,7 +45,7 @@ open (const char *__path, int __oflag, ...)
 
   if (__builtin_constant_p (__oflag))
     {
-      if ((__oflag & O_CREAT) != 0 && __va_arg_pack_len () < 1)
+      if (__OPEN_NEEDS_MODE (__oflag) && __va_arg_pack_len () < 1)
 	{
 	  __open_missing_mode ();
 	  return __open_2 (__path, __oflag);
@@ -67,7 +67,7 @@ extern int __REDIRECT (__open64_alias, (const char *__path, int __oflag,
 __errordecl (__open64_too_many_args,
 	     "open64 can be called either with 2 or 3 arguments, not more");
 __errordecl (__open64_missing_mode,
-	     "open64 with O_CREAT in second argument needs 3 arguments");
+	     "open64 with O_CREAT or O_TMPFILE in second argument needs 3 arguments");
 
 __fortify_function int
 open64 (const char *__path, int __oflag, ...)
@@ -77,7 +77,7 @@ open64 (const char *__path, int __oflag, ...)
 
   if (__builtin_constant_p (__oflag))
     {
-      if ((__oflag & O_CREAT) != 0 && __va_arg_pack_len () < 1)
+      if (__OPEN_NEEDS_MODE (__oflag) && __va_arg_pack_len () < 1)
 	{
 	  __open64_missing_mode ();
 	  return __open64_2 (__path, __oflag);
@@ -111,7 +111,7 @@ extern int __REDIRECT (__openat_alias, (int __fd, const char *__path,
 __errordecl (__openat_too_many_args,
 	     "openat can be called either with 3 or 4 arguments, not more");
 __errordecl (__openat_missing_mode,
-	     "openat with O_CREAT in third argument needs 4 arguments");
+	     "openat with O_CREAT or O_TMPFILE in third argument needs 4 arguments");
 
 __fortify_function int
 openat (int __fd, const char *__path, int __oflag, ...)
@@ -121,7 +121,7 @@ openat (int __fd, const char *__path, int __oflag, ...)
 
   if (__builtin_constant_p (__oflag))
     {
-      if ((__oflag & O_CREAT) != 0 && __va_arg_pack_len () < 1)
+      if (__OPEN_NEEDS_MODE (__oflag) && __va_arg_pack_len () < 1)
 	{
 	  __openat_missing_mode ();
 	  return __openat_2 (__fd, __path, __oflag);
@@ -145,7 +145,7 @@ extern int __REDIRECT (__openat64_alias, (int __fd, const char *__path,
 __errordecl (__openat64_too_many_args,
 	     "openat64 can be called either with 3 or 4 arguments, not more");
 __errordecl (__openat64_missing_mode,
-	     "openat64 with O_CREAT in third argument needs 4 arguments");
+	     "openat64 with O_CREAT or O_TMPFILE in third argument needs 4 arguments");
 
 __fortify_function int
 openat64 (int __fd, const char *__path, int __oflag, ...)
@@ -155,7 +155,7 @@ openat64 (int __fd, const char *__path, int __oflag, ...)
 
   if (__builtin_constant_p (__oflag))
     {
-      if ((__oflag & O_CREAT) != 0 && __va_arg_pack_len () < 1)
+      if (__OPEN_NEEDS_MODE (__oflag) && __va_arg_pack_len () < 1)
 	{
 	  __openat64_missing_mode ();
 	  return __openat64_2 (__fd, __path, __oflag);
diff --git a/io/fcntl.h b/io/fcntl.h
index 71f5e52..c6812c4 100644
--- a/io/fcntl.h
+++ b/io/fcntl.h
@@ -34,6 +34,15 @@ __BEGIN_DECLS
    numbers and flag bits for `open', `fcntl', et al.  */
 #include <bits/fcntl.h>
 
+/* Detect if open needs mode as a third argument (or for openat as a fourth
+   argument).  */
+#ifdef __O_TMPFILE
+# define __OPEN_NEEDS_MODE(oflag) \
+  (((oflag) & O_CREAT) != 0 || ((oflag) & __O_TMPFILE) == __O_TMPFILE)
+#else
+# define __OPEN_NEEDS_MODE(oflag) (((oflag) & O_CREAT) != 0)
+#endif
+
 /* POSIX.1-2001 specifies that these types are defined by <fcntl.h>.
    Earlier POSIX standards permitted any type ending in `_t' to be defined
    by any POSIX header, so we don't conditionalize the definitions here.  */
@@ -160,8 +169,9 @@ typedef __pid_t pid_t;
 extern int fcntl (int __fd, int __cmd, ...);
 
 /* Open FILE and return a new file descriptor for it, or -1 on error.
-   OFLAG determines the type of access used.  If O_CREAT is on OFLAG,
-   the third argument is taken as a `mode_t', the mode of the created file.
+   OFLAG determines the type of access used.  If O_CREAT or O_TMPFILE is set
+   in OFLAG, the third argument is taken as a `mode_t', the mode of the
+   created file.
 
    This function is a cancellation point and therefore not marked with
    __THROW.  */
diff --git a/io/open.c b/io/open.c
index cf1245b..c0000ba 100644
--- a/io/open.c
+++ b/io/open.c
@@ -23,7 +23,7 @@
 #include <stdio.h>
 
 
-/* Open FILE with access OFLAG.  If OFLAG includes O_CREAT,
+/* Open FILE with access OFLAG.  If O_CREAT or O_TMPFILE is in OFLAG,
    a third argument is the file protection.  */
 int
 __libc_open (file, oflag)
@@ -38,7 +38,7 @@ __libc_open (file, oflag)
       return -1;
     }
 
-  if (oflag & O_CREAT)
+  if (__OPEN_NEEDS_MODE (oflag))
     {
       va_list arg;
       va_start(arg, oflag);
diff --git a/io/open64.c b/io/open64.c
index edd5fd3..f87ee57 100644
--- a/io/open64.c
+++ b/io/open64.c
@@ -21,7 +21,7 @@
 #include <stddef.h>
 #include <stdio.h>
 
-/* Open FILE with access OFLAG.  If OFLAG includes O_CREAT,
+/* Open FILE with access OFLAG.  If O_CREAT or O_TMPFILE is in OFLAG,
    a third argument is the file protection.  */
 int
 __libc_open64 (file, oflag)
@@ -36,7 +36,7 @@ __libc_open64 (file, oflag)
       return -1;
     }
 
-  if (oflag & O_CREAT)
+  if (__OPEN_NEEDS_MODE (oflag))
     {
       va_list arg;
       va_start (arg, oflag);
diff --git a/io/open64_2.c b/io/open64_2.c
index d56dc65..0fd562d 100644
--- a/io/open64_2.c
+++ b/io/open64_2.c
@@ -22,8 +22,8 @@
 int
 __open64_2 (const char *file, int oflag)
 {
-  if (oflag & O_CREAT)
-    __fortify_fail ("invalid open64 call: O_CREAT without mode");
+  if (__OPEN_NEEDS_MODE (oflag))
+    __fortify_fail ("invalid open64 call: O_CREAT or O_TMPFILE without mode");
 
   return __open64 (file, oflag);
 }
diff --git a/io/open_2.c b/io/open_2.c
index c07ecdd..f11ebe0 100644
--- a/io/open_2.c
+++ b/io/open_2.c
@@ -22,8 +22,8 @@
 int
 __open_2 (const char *file, int oflag)
 {
-  if (oflag & O_CREAT)
-    __fortify_fail ("invalid open call: O_CREAT without mode");
+  if (__OPEN_NEEDS_MODE (oflag))
+    __fortify_fail ("invalid open call: O_CREAT or O_TMPFILE without mode");
 
   return __open (file, oflag);
 }
diff --git a/io/openat.c b/io/openat.c
index e54eb9b..08d6184 100644
--- a/io/openat.c
+++ b/io/openat.c
@@ -31,7 +31,7 @@ int __have_atfcts;
 #endif
 
 /* Open FILE with access OFLAG.  Interpret relative paths relative to
-   the directory associated with FD.  If OFLAG includes O_CREAT, a
+   the directory associated with FD.  If O_CREAT or O_TMPFILE is in OFLAG, a
    third argument is the file protection.  */
 int
 __openat (int fd, const char *file, int oflag, ...)
@@ -58,7 +58,7 @@ __openat (int fd, const char *file, int oflag, ...)
 	}
     }
 
-  if (oflag & O_CREAT)
+  if (__OPEN_NEEDS_MODE (oflag))
     {
       va_list arg;
       va_start (arg, oflag);
diff --git a/io/openat64.c b/io/openat64.c
index 7801a92..060fdf9 100644
--- a/io/openat64.c
+++ b/io/openat64.c
@@ -24,7 +24,7 @@
 #include <libc-internal.h>
 
 /* Open FILE with access OFLAG.  Interpret relative paths relative to
-   the directory associated with FD.  If OFLAG includes O_CREAT, a
+   the directory associated with FD.  If O_CREAT or O_TMPFILE is in OFLAG, a
    third argument is the file protection.  */
 int
 __openat64 (int fd, const char *file, int oflag, ...)
@@ -51,7 +51,7 @@ __openat64 (int fd, const char *file, int oflag, ...)
 	}
     }
 
-  if (oflag & O_CREAT)
+  if (__OPEN_NEEDS_MODE (oflag))
     {
       va_list arg;
       va_start (arg, oflag);
diff --git a/io/openat64_2.c b/io/openat64_2.c
index 96f04d2..8548c3d 100644
--- a/io/openat64_2.c
+++ b/io/openat64_2.c
@@ -22,8 +22,8 @@
 int
 __openat64_2 (int fd, const char *file, int oflag)
 {
-  if (oflag & O_CREAT)
-    __fortify_fail ("invalid openat64 call: O_CREAT without mode");
+  if (__OPEN_NEEDS_MODE (oflag))
+    __fortify_fail ("invalid openat64 call: O_CREAT or O_TMPFILE without mode");
 
   return __openat64 (fd, file, oflag);
 }
diff --git a/io/openat_2.c b/io/openat_2.c
index 2345cc2..54a98be 100644
--- a/io/openat_2.c
+++ b/io/openat_2.c
@@ -22,8 +22,8 @@
 int
 __openat_2 (int fd, const char *file, int oflag)
 {
-  if (oflag & O_CREAT)
-    __fortify_fail ("invalid openat call: O_CREAT without mode");
+  if (__OPEN_NEEDS_MODE (oflag))
+    __fortify_fail ("invalid openat call: O_CREAT or O_TMPFILE without mode");
 
   return __openat (fd, file, oflag);
 }