Le 2018-11-15 18:05, Sasha Levin a écrit :
On Tue, Oct 23, 2018 at 08:37:39PM +0200, Loic wrote:
Hello,
Please picked up this patch for linux 4.9 and 4.14 (linux 4.4 needs a
small modification).
Indeed, this code will be beneficial to the GNU/Linux distributions
that use a longterm kernel.
Compiled/tested without problem.
Thank.
[ Upstream commit 30aba6656f61ed44cba445a3c0d38b296fa9e8f5 ]
From: Salvatore Mesoraca <s.mesoraca16@xxxxxxxxx>
Date: Thu, 23 Aug 2018 17:00:35 -0700
Subject: namei: allow restricted O_CREAT of FIFOs and regular files
Disallows open of FIFOs or regular files not owned by the user in
world
writable sticky directories, unless the owner is the same as that of
the
directory or the file is opened without the O_CREAT flag. The purpose
is to make data spoofing attacks harder. This protection can be
turned
on and off separately for FIFOs and regular files via sysctl, just
like
the symlinks/hardlinks protection. This patch is based on Openwall's
"HARDEN_FIFO" feature by Solar Designer.
This is a brief list of old vulnerabilities that could have been
prevented
by this feature, some of them even allow for privilege escalation:
CVE-2000-1134
CVE-2007-3852
CVE-2008-0525
CVE-2009-0416
CVE-2011-4834
CVE-2015-1838
CVE-2015-7442
CVE-2016-7489
This list is not meant to be complete. It's difficult to track down
all
vulnerabilities of this kind because they were often reported without
any
mention of this particular attack vector. In fact, before
hardlinks/symlinks restrictions, fifos/regular files weren't the
favorite
vehicle to exploit them.
[s.mesoraca16@xxxxxxxxx: fix bug reported by Dan Carpenter]
Link: https://lkml.kernel.org/r/20180426081456.GA7060@mwanda
Link:
http://lkml.kernel.org/r/1524829819-11275-1-git-send-email-s.mesoraca16@xxxxxxxxx
[keescook@xxxxxxxxxxxx: drop pr_warn_ratelimited() in favor of audit
changes in the future]
[keescook@xxxxxxxxxxxx: adjust commit subjet]
Link: http://lkml.kernel.org/r/20180416175918.GA13494@beast
Signed-off-by: Salvatore Mesoraca <s.mesoraca16@xxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Suggested-by: Solar Designer <solar@xxxxxxxxxxxx>
Suggested-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Loic, could you please sign off on this one? You did so for the other
but not this.
Of course if you need it.
Signed-off-by: Loic Fr. <hackurx@xxxxxxxxxx>
--
Thanks,
Sasha
Thanks to you too
Best regards,
Loic
