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authorEric Rannaud <e@nanocritical.com>2015-02-24 13:12:26 +0530
committerAurelien Jarno <aurelien@aurel32.net>2016-08-14 18:16:12 +0200
commit9d328da0a82c8cba8dd7f9e537af2dd8ca60ebdf (patch)
tree5248983bfe98f70574cae9854c640d27a7a6878d
parent66986dec455c2011085a04b72a5bd55d9f9c7d1c (diff)
downloadglibc-9d328da0a82c8cba8dd7f9e537af2dd8ca60ebdf.tar.gz
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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.
	* ports/sysdeps/unix/sysv/linux/generic/open.c (__libc_open): Likewise.
	(__open_nocancel): Likewise.
	* ports/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.

(cherry picked from commit 65f6f938cd562a614a68e15d0581a34b177ec29d)
-rw-r--r--ChangeLog25
-rw-r--r--NEWS6
-rw-r--r--io/bits/fcntl2.h18
-rw-r--r--io/fcntl.h14
-rw-r--r--io/open.c4
-rw-r--r--io/open64.c4
-rw-r--r--io/open64_2.c4
-rw-r--r--io/open_2.c4
-rw-r--r--io/openat.c4
-rw-r--r--io/openat64.c4
-rw-r--r--io/openat64_2.c4
-rw-r--r--io/openat_2.c4
-rw-r--r--ports/sysdeps/unix/sysv/linux/generic/open.c6
-rw-r--r--ports/sysdeps/unix/sysv/linux/generic/open64.c4
-rw-r--r--sysdeps/mach/hurd/open.c4
-rw-r--r--sysdeps/mach/hurd/openat.c4
-rw-r--r--sysdeps/posix/open64.c4
-rw-r--r--sysdeps/unix/sysv/linux/dl-openat64.c2
-rw-r--r--sysdeps/unix/sysv/linux/open64.c4
-rw-r--r--sysdeps/unix/sysv/linux/openat.c6
20 files changed, 82 insertions, 47 deletions
diff --git a/ChangeLog b/ChangeLog
index 5d3bc8f7d2..3d2063bb1c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,28 @@
+2015-02-24  Eric Rannaud  <e@nanocritical.com>
+
+	[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.
+	* ports/sysdeps/unix/sysv/linux/generic/open.c (__libc_open): Likewise.
+	(__open_nocancel): Likewise.
+	* ports/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.
+
 2016-07-11  Florian Weimer  <fweimer@redhat.com>
 
 	[BZ #19018]
diff --git a/NEWS b/NEWS
index 41481cd33e..473e35adf9 100644
--- a/NEWS
+++ b/NEWS
@@ -11,9 +11,9 @@ Version 2.19.1
 
   15946, 16009, 16545, 16574, 16623, 16657, 16695, 16743, 16758, 16759,
   16760, 16878, 16882, 16885, 16916, 16932, 16943, 16958, 17048, 17062,
-  17069, 17079, 17137, 17153, 17213, 17263, 17269, 17325, 17555, 17905,
-  18007, 18032, 18080, 18240, 18287, 18508, 18665, 18905, 18928, 19018,
-  19779, 19791, 19879, 20010, 20112.
+  17069, 17079, 17137, 17153, 17213, 17263, 17269, 17325, 17523, 17555,
+  17905, 18007, 18032, 18080, 18240, 18287, 18508, 18665, 18905, 18928,
+  19018, 19779, 19791, 19879, 20010, 20112.
 
 * A buffer overflow in gethostbyname_r and related functions performing DNS
   requests has been fixed.  If the NSS functions were called with a
diff --git a/io/bits/fcntl2.h b/io/bits/fcntl2.h
index 4f13b10706..bb8d233b01 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 28d83aeab5..16f792e7b4 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 24aa380339..d1df5c38d3 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 3f3d2e8bbd..def4e0b1b2 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 7cafbba4fc..dced8abbe7 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 65d2c1c845..d5b3afe530 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 2d822702af..f3ac8a7532 100644
--- a/io/openat.c
+++ b/io/openat.c
@@ -30,7 +30,7 @@ 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 (fd, file, oflag)
@@ -60,7 +60,7 @@ __openat (fd, file, 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 c0c4e19589..d104bc123b 100644
--- a/io/openat64.c
+++ b/io/openat64.c
@@ -23,7 +23,7 @@
 #include <sys/stat.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 (fd, file, oflag)
@@ -53,7 +53,7 @@ __openat64 (fd, file, 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 6cfea6a9aa..9c22a28cad 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 9e38c14267..d15d1e922d 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);
 }
diff --git a/ports/sysdeps/unix/sysv/linux/generic/open.c b/ports/sysdeps/unix/sysv/linux/generic/open.c
index 4f73fa019c..b4c68344c2 100644
--- a/ports/sysdeps/unix/sysv/linux/generic/open.c
+++ b/ports/sysdeps/unix/sysv/linux/generic/open.c
@@ -22,14 +22,14 @@
 #include <stdio.h>
 #include <sysdep-cancel.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 (const char *file, int oflag, ...)
 {
   int mode = 0;
 
-  if (oflag & O_CREAT)
+  if (__OPEN_NEEDS_MODE (oflag))
     {
       va_list arg;
       va_start (arg, oflag);
@@ -59,7 +59,7 @@ __open_nocancel (const char *file, int oflag, ...)
 {
   int mode = 0;
 
-  if (oflag & O_CREAT)
+  if (__OPEN_NEEDS_MODE (oflag))
     {
       va_list arg;
       va_start (arg, oflag);
diff --git a/ports/sysdeps/unix/sysv/linux/generic/open64.c b/ports/sysdeps/unix/sysv/linux/generic/open64.c
index 93d79e381f..faea4df951 100644
--- a/ports/sysdeps/unix/sysv/linux/generic/open64.c
+++ b/ports/sysdeps/unix/sysv/linux/generic/open64.c
@@ -22,14 +22,14 @@
 #include <stdio.h>
 #include <sysdep-cancel.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 (const char *file, int oflag, ...)
 {
   int mode = 0;
 
-  if (oflag & O_CREAT)
+  if (__OPEN_NEEDS_MODE (oflag))
     {
       va_list arg;
       va_start (arg, oflag);
diff --git a/sysdeps/mach/hurd/open.c b/sysdeps/mach/hurd/open.c
index 7d9b2de70c..f003d032e4 100644
--- a/sysdeps/mach/hurd/open.c
+++ b/sysdeps/mach/hurd/open.c
@@ -22,7 +22,7 @@
 #include <hurd.h>
 #include <hurd/fd.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 (const char *file, int oflag, ...)
@@ -30,7 +30,7 @@ __libc_open (const char *file, int oflag, ...)
   mode_t mode;
   io_t port;
 
-  if (oflag & O_CREAT)
+  if (__OPEN_NEEDS_MODE (oflag))
     {
       va_list arg;
       va_start (arg, oflag);
diff --git a/sysdeps/mach/hurd/openat.c b/sysdeps/mach/hurd/openat.c
index 318cb229ef..83ffe13e5a 100644
--- a/sysdeps/mach/hurd/openat.c
+++ b/sysdeps/mach/hurd/openat.c
@@ -26,7 +26,7 @@
 #include <hurd/fd.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
 __openat (fd, file, oflag)
@@ -37,7 +37,7 @@ __openat (fd, file, oflag)
   mode_t mode;
   io_t port;
 
-  if (oflag & O_CREAT)
+  if (__OPEN_NEEDS_MODE (oflag))
     {
       va_list arg;
       va_start (arg, oflag);
diff --git a/sysdeps/posix/open64.c b/sysdeps/posix/open64.c
index 64d192af97..4b7ec362be 100644
--- a/sysdeps/posix/open64.c
+++ b/sysdeps/posix/open64.c
@@ -19,14 +19,14 @@
 #include <stdarg.h>
 #include <sysdep-cancel.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 (const char *file, int oflag, ...)
 {
   int mode = 0;
 
-  if (oflag & O_CREAT)
+  if (__OPEN_NEEDS_MODE (oflag))
     {
       va_list arg;
       va_start (arg, oflag);
diff --git a/sysdeps/unix/sysv/linux/dl-openat64.c b/sysdeps/unix/sysv/linux/dl-openat64.c
index 9d00b459a6..5ac16a2213 100644
--- a/sysdeps/unix/sysv/linux/dl-openat64.c
+++ b/sysdeps/unix/sysv/linux/dl-openat64.c
@@ -28,7 +28,7 @@ openat64 (dfd, file, oflag)
      const char *file;
      int oflag;
 {
-  assert ((oflag & O_CREAT) == 0);
+  assert (!__OPEN_NEEDS_MODE (oflag));
 
 #ifdef __NR_openat
   return INLINE_SYSCALL (openat, 3, dfd, file, oflag | O_LARGEFILE);
diff --git a/sysdeps/unix/sysv/linux/open64.c b/sysdeps/unix/sysv/linux/open64.c
index 0d63806d04..6d91b21c3c 100644
--- a/sysdeps/unix/sysv/linux/open64.c
+++ b/sysdeps/unix/sysv/linux/open64.c
@@ -21,14 +21,14 @@
 #include <stdio.h>
 #include <sysdep-cancel.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 (const char *file, int oflag, ...)
 {
   int mode = 0;
 
-  if (oflag & O_CREAT)
+  if (__OPEN_NEEDS_MODE (oflag))
     {
       va_list arg;
       va_start (arg, oflag);
diff --git a/sysdeps/unix/sysv/linux/openat.c b/sysdeps/unix/sysv/linux/openat.c
index 9bb8acec1f..5a75f52941 100644
--- a/sysdeps/unix/sysv/linux/openat.c
+++ b/sysdeps/unix/sysv/linux/openat.c
@@ -148,8 +148,8 @@ OPENAT_NOT_CANCEL (fd, file, oflag, mode)
 
 
 /* Open FILE with access OFLAG.  Interpret relative paths relative to
-   the directory associated with FD.  If OFLAG includes O_CREAT, a
-   third argument is the file protection.  */
+   the directory associated with FD.  If OFLAG includes O_CREAT or
+   O_TMPFILE, a fourth argument is the file protection.  */
 int
 __OPENAT (fd, file, oflag)
      int fd;
@@ -157,7 +157,7 @@ __OPENAT (fd, file, oflag)
      int oflag;
 {
   mode_t mode = 0;
-  if (oflag & O_CREAT)
+  if (__OPEN_NEEDS_MODE (oflag))
     {
       va_list arg;
       va_start (arg, oflag);