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Date:   Wed, 24 Jun 2020 00:50:42 +0300
From:   Alexey Dobriyan <adobriyan@gmail.com>
To:     Christian Kujau <lists@nerdbynature.de>
Cc:     Kees Cook <keescook@chromium.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Willy Tarreau <w@1wt.eu>,
        Dan Carpenter <dan.carpenter@oracle.com>,
        linux-kernel@vger.kernel.org
Subject: Re: process '/usr/bin/rsync' started with executable stack
Message-ID: <20200623215042.GA43266@localhost.localdomain>
References: <alpine.DEB.2.22.1.446.2006231023390.3892@trent.utfs.org>
 <202006231131.AD0A7F5F@keescook>
 <alpine.DEB.2.22.1.446.2006231430280.3892@trent.utfs.org>
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On Tue, Jun 23, 2020 at 02:33:50PM -0700, Christian Kujau wrote:
> On Tue, 23 Jun 2020, Kees Cook wrote:
> > > $ checksec --format=json --extended --file=`which rsync` | jq
> > > {
> > >   "/usr/bin/rsync": {
> > >     "relro": "full",
> > >     "canary": "yes",
> > >     "nx": "no",
> > ^^^^^^^^^^^^^^^^^^
> > 
> > It is, indeed, marked executable, it seems. What distro is this?
> 
> Arch Linux (x86-64) with 5.6.5.a-1-hardened[0], running in a Xen DomU.

BTW this bug was exactly the one described in the changelog:
compiling assembly brings executable stack by default:

	$ git-show 73faaab26d7db19ae6e04396a6e9d6372ed8e4ad
	commit 73faaab26d7db19ae6e04396a6e9d6372ed8e4ad

	    Pass --noexecstack to assembler.

	--- a/Makefile.in
	+++ b/Makefile.in
	@@ -135,7 +135,7 @@ simd-checksum-x86_64.o: simd-checksum-x86_64.cpp
	        $(CXX) -I. $(CXXFLAGS) $(CPPFLAGS) -c -o $@ $(srcdir)/simd-checksum-x86_64.cpp

	 lib/md5-asm-x86_64.o: lib/md5-asm-x86_64.S config.h lib/md-defines.h
	-       $(CC) -I. -c -o $@ $(srcdir)/lib/md5-asm-x86_64.S
	+       $(CC) -I. -Wa,--noexecstack -c -o $@ $(srcdir)/lib/md5-asm-x86_64.S