Bug#832521: Please backport fix for O_TMPFILE for jessie

[Aurelien Jarno]

On 2016-07-26 15:10, Michael Biebl wrote:
> Source: glibc
> Version: 2.19-18+deb8u4
> Severity: normal
> Tags: patch
> 
> Hi,

Hi,

> while working on a backport of systemd v230 for jessie, we ran into
> issues. Our test-suite was failing on i386, specifically test-tmpfiles.
> It turns out, the files created wit O_TMPFILE had broken permissions and
> were unreadable. After further investigation, this turned out to be a
> bug in glibc[2].
> I've backported the commit to 2.19 and with that patch applied, our
> test-suite completed successfully on i386. The patch I've attached did
> compile successfully on i386 and it fixed our issue in systemd. There
> where a few conflicts when cherry-picking the patch, so please
> double-check, just in case I missed something.

The conflicts concerns file which have been moved out of the ports/
directory. The changes to generic/open.c and generic/open64.c should
therefore be applied to these files on the ports directory. There are
used by arm64 so we also want the bug to be fixed there.

I'll get the bug fixed by backporting this commit to the upstream 2.19
stable branch, and then pull this branch in the debian package.

> It would be great if you could include this patch in your next stable
> upload. I noticed that there is already an accepted upload
> 2.19-18+deb8u5 for jessie 8.6. It would be awesome if you could make a
> follow-up upload 2.19-18+deb8u6 to get that fix into 8.6 (I think there
> is still some time left for that). If not, please consider including it
> for 8.7.

I am still doing tests for other fixes we have pending, I expect to open
a bug report against release.debian.org for an upload to stable in the
next days. If it get accepted, that should be in time for 8.6.

> The commit itself has been in unstable/stretch for a while, so seen some
> wider testing.

Indeed, and the fix looks straightforward and easily reviewable.

Aurelien

-- 
Aurelien Jarno  GPG: 4096R/1DDD8C9B
aurel...@aurel32.net http://www.aurel32.net

Bug#832521: Please backport fix for O_TMPFILE for jessie

[Michael Biebl]

Source: glibc
Version: 2.19-18+deb8u4
Severity: normal
Tags: patch

Hi,

while working on a backport of systemd v230 for jessie, we ran into
issues. Our test-suite was failing on i386, specifically test-tmpfiles.
It turns out, the files created wit O_TMPFILE had broken permissions and
were unreadable. After further investigation, this turned out to be a
bug in glibc[2].
I've backported the commit to 2.19 and with that patch applied, our
test-suite completed successfully on i386. The patch I've attached did
compile successfully on i386 and it fixed our issue in systemd. There
where a few conflicts when cherry-picking the patch, so please
double-check, just in case I missed something.

It would be great if you could include this patch in your next stable
upload. I noticed that there is already an accepted upload
2.19-18+deb8u5 for jessie 8.6. It would be awesome if you could make a
follow-up upload 2.19-18+deb8u6 to get that fix into 8.6 (I think there
is still some time left for that). If not, please consider including it
for 8.7.
The commit itself has been in unstable/stretch for a while, so seen some
wider testing.

Regards,
Michael

[1] 
https://buildd.debian.org/status/fetch.php?pkg=systemd=i386=230-7~bpo8%2B1=1468945449
[2] https://sourceware.org/bugzilla/show_bug.cgi?id=17523
-- System Information:
Debian Release: stretch/sid
  APT prefers unstable-debug
  APT policy: (500, 'unstable-debug'), (500, 'unstable'), (200, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.6.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
>From dfff01413587d937e077d94b07b2fa0b7d6f8080 Mon Sep 17 00:00:00 2001
From: Eric Rannaud 
Date: Tue, 24 Feb 2015 13:12:26 +0530
Subject: [PATCH] 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.

Conflicts:
	ChangeLog
	NEWS
	sysdeps/unix/sysv/linux/generic/open.c
	sysdeps/unix/sysv/linux/generic/open64.c

(cherry-picked from commit 65f6f938cd562a614a68e15d0581a34b177ec29d)
---
 io/bits/fcntl2.h  | 18 +-
 io/fcntl.h| 14 --
 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/dl-openat64.c |  2 +-
 sysdeps/unix/sysv/linux/open64.c  |  4 ++--
 sysdeps/unix/sysv/linux/openat.c  |  6 +++---
 16 files changed, 49 insertions(+), 39 deletions(-)

diff --git a/io/bits/fcntl2.h b/io/bits/fcntl2.h
index 4f13b10..bb8d233 100644
--- a/io/bits/fcntl2.h
+++ b/io/bits/fcntl2.h
@@ -20,7 +20,7 @@
 # error "Never include  directly; use  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