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[PATCH 1/1] linux: open and openat ignore 'mode' with O_TMPFILE in flags


Both open and openat load the 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 the 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 system-specific macro __OPEN_NEEDS_MODE(oflag): by default,
it tests for O_CREAT in oflag; on Linux, it tests for either O_CREAT or
__O_TMPFILE (even if __USE_GNU is not defined).

Tested on Linux x86_64.

	[BZ #17523]
	* io/fcntl.h: Default definition of __OPEN_NEEDS_MODE(oflag).
	* sysdeps/unix/sysv/linux/bits/fcntl-linux.h: Linux-specific definition of __OPEN_NEEDS_MODE().
	* io/bits/fcntl2.h: Use __OPEN_NEEDS_MODE().
	* io/open.c: Likewise.
	* io/open64.c: Likewise.
	* io/open64_2.c: Likewise.
	* io/open_2.c: Likewise.
	* io/openat.c: Likewise.
	* io/openat64.c: Likewise.
	* io/openat64_2.c: Likewise.
	* io/openat_2.c: Likewise.
	* sysdeps/mach/hurd/open.c: Likewise.
	* sysdeps/mach/hurd/openat.c: Likewise.
	* sysdeps/posix/open64.c: Likewise.
	* sysdeps/unix/sysv/linux/dl-openat64.c: Likewise.
	* sysdeps/unix/sysv/linux/generic/open.c: Likewise.
	* sysdeps/unix/sysv/linux/generic/open64.c: Likewise.
	* sysdeps/unix/sysv/linux/open64.c: Likewise.
	* sysdeps/unix/sysv/linux/openat.c: Likewise.
---
 io/bits/fcntl2.h                           | 20 ++++++++++----------
 io/fcntl.h                                 |  6 +++++-
 io/open.c                                  |  4 ++--
 io/open64.c                                |  4 ++--
 io/open64_2.c                              |  4 ++--
 io/open_2.c                                |  4 ++--
 io/openat.c                                |  4 ++--
 io/openat64.c                              |  4 ++--
 io/openat64_2.c                            |  4 ++--
 io/openat_2.c                              |  4 ++--
 sysdeps/mach/hurd/open.c                   |  4 ++--
 sysdeps/mach/hurd/openat.c                 |  4 ++--
 sysdeps/posix/open64.c                     |  4 ++--
 sysdeps/unix/sysv/linux/bits/fcntl-linux.h |  3 +++
 sysdeps/unix/sysv/linux/dl-openat64.c      |  2 +-
 sysdeps/unix/sysv/linux/generic/open.c     |  6 +++---
 sysdeps/unix/sysv/linux/generic/open64.c   |  4 ++--
 sysdeps/unix/sysv/linux/open64.c           |  4 ++--
 sysdeps/unix/sysv/linux/openat.c           |  2 +-
 19 files changed, 49 insertions(+), 42 deletions(-)

diff --git a/io/bits/fcntl2.h b/io/bits/fcntl2.h
index 4f13b1070673..677e349f4ca3 100644
--- a/io/bits/fcntl2.h
+++ b/io/bits/fcntl2.h
@@ -20,8 +20,8 @@
 # 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
-   appropriate third/fourth parameter.  */
+/* Check that calls to open and openat have an appropriate third/fourth
+   parameter.  */
 #ifndef __USE_FILE_OFFSET64
 extern int __open_2 (const char *__path, int __oflag) __nonnull ((1));
 extern int __REDIRECT (__open_alias, (const char *__path, int __oflag, ...),
@@ -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 e.g. O_CREAT 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 e.g. O_CREAT 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 e.g. O_CREAT 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 e.g. O_CREAT 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 cf512dd27f8c..e73d701f3eb0 100644
--- a/io/fcntl.h
+++ b/io/fcntl.h
@@ -34,6 +34,10 @@ __BEGIN_DECLS
    numbers and flag bits for `open', `fcntl', et al.  */
 #include <bits/fcntl.h>
 
+#ifndef __OPEN_NEEDS_MODE
+# 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.  */
@@ -160,7 +164,7 @@ 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,
+   OFLAG determines the type of access used.  If __OPEN_NEEDS_MODE(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
diff --git a/io/open.c b/io/open.c
index 24aa38033984..4a00c3359e02 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 __OPEN_NEEDS_MODE(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 3f3d2e8bbd4b..e3f2630bcf06 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 __OPEN_NEEDS_MODE(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 7cafbba4fcc4..b95b205d92de 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: missing mode argument");
 
   return __open64 (file, oflag);
 }
diff --git a/io/open_2.c b/io/open_2.c
index 65d2c1c845bc..e405280eeb5a 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: missing mode argument");
 
   return __open (file, oflag);
 }
diff --git a/io/openat.c b/io/openat.c
index 2d822702af43..aff079eb9fd4 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 __OPEN_NEEDS_MODE(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 c0c4e19589bc..23a27a8baefd 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 __OPEN_NEEDS_MODE(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 6cfea6a9aace..20e1ecbed8d8 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: missing mode argument");
 
   return __openat64 (fd, file, oflag);
 }
diff --git a/io/openat_2.c b/io/openat_2.c
index 9e38c142671c..947a5d65b09f 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: missing mode argument");
 
   return __openat (fd, file, oflag);
 }
diff --git a/sysdeps/mach/hurd/open.c b/sysdeps/mach/hurd/open.c
index 7d9b2de70c38..5c3f40d4d505 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 __OPEN_NEEDS_MODE(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 318cb229ef64..cc8d97389c20 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 __OPEN_NEEDS_MODE(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 64d192af9793..9d484884d467 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 __OPEN_NEEDS_MODE(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/bits/fcntl-linux.h b/sysdeps/unix/sysv/linux/bits/fcntl-linux.h
index e224dab58be2..906c6189043f 100644
--- a/sysdeps/unix/sysv/linux/bits/fcntl-linux.h
+++ b/sysdeps/unix/sysv/linux/bits/fcntl-linux.h
@@ -100,6 +100,9 @@
 # define __O_TMPFILE   020200000
 #endif
 
+#define __OPEN_NEEDS_MODE(oflag) \
+  ( ((oflag) & O_CREAT) != 0 || ((oflag) & __O_TMPFILE) == __O_TMPFILE )
+
 #ifndef F_GETLK
 # ifndef __USE_FILE_OFFSET64
 #  define F_GETLK	5	/* Get record locking info.  */
diff --git a/sysdeps/unix/sysv/linux/dl-openat64.c b/sysdeps/unix/sysv/linux/dl-openat64.c
index 9d00b459a60d..fea11da41fcb 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/generic/open.c b/sysdeps/unix/sysv/linux/generic/open.c
index 4f73fa019cd8..2a4a219cfe31 100644
--- a/sysdeps/unix/sysv/linux/generic/open.c
+++ b/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 __OPEN_NEEDS_MODE(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/sysdeps/unix/sysv/linux/generic/open64.c b/sysdeps/unix/sysv/linux/generic/open64.c
index 93d79e381fab..4ad004bb7f67 100644
--- a/sysdeps/unix/sysv/linux/generic/open64.c
+++ b/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 __OPEN_NEEDS_MODE(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/open64.c b/sysdeps/unix/sysv/linux/open64.c
index 0d63806d04ae..fa1ea270cac5 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 __OPEN_NEEDS_MODE(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 36555b958fdd..21748339ee1d 100644
--- a/sysdeps/unix/sysv/linux/openat.c
+++ b/sysdeps/unix/sysv/linux/openat.c
@@ -67,7 +67,7 @@ __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);
-- 
2.1.2


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