From 65f6f938cd562a614a68e15d0581a34b177ec29d Mon Sep 17 00:00:00 2001
From: Eric Rannaud <e@nanocritical.com>
Date: Tue, 24 Feb 2015 13:12:26 +0530
Subject: 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.
---
sysdeps/unix/sysv/linux/generic/open64.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
(limited to 'sysdeps/unix/sysv/linux/generic/open64.c')
diff --git a/sysdeps/unix/sysv/linux/generic/open64.c b/sysdeps/unix/sysv/linux/generic/open64.c
index 4feedbaff5..374e41cf3a 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 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);
--
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