Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1568832 > unrolled thread

[PATCH v2 0/2] setgid hardening

Started byAndy Lutomirski <luto@kernel.org>
First post2017-01-28 04:00 +0100
Last post2017-01-31 05:00 +0100
Articles 3 — 3 participants

Back to article view | Back to linux.kernel


Contents

  [PATCH v2 0/2] setgid hardening Andy Lutomirski <luto@kernel.org> - 2017-01-28 04:00 +0100
    Re: [PATCH v2 0/2] setgid hardening Michael Kerrisk <mtk.manpages@gmail.com> - 2017-01-31 05:00 +0100
      Re: [PATCH v2 0/2] setgid hardening Andy Lutomirski <luto@amacapital.net> - 2017-01-31 05:00 +0100

#1568832 — [PATCH v2 0/2] setgid hardening

FromAndy Lutomirski <luto@kernel.org>
Date2017-01-28 04:00 +0100
Subject[PATCH v2 0/2] setgid hardening
Message-ID<t4rp7-3Yv-3@gated-at.bofh.it>
The kernel has some dangerous behavior involving the creation and
modification of setgid executables.  These issues aren't kernel
security bugs per se, but they have been used to turn various
filesystem permission oddities into reliably privilege escalation
exploits.

See http://www.halfdog.net/Security/2015/SetgidDirectoryPrivilegeEscalation/
for a nice writeup.

Let's fix them for real.

Changes from v1:
 - Fix uninitialized variable issue (Willy, Ben)
 - Also check current creds in should_remove_suid() (Ben)

Andy Lutomirski (2):
  fs: Check f_cred as well as of current's creds in should_remove_suid()
  fs: Harden against open(..., O_CREAT, 02777) in a setgid directory

 fs/inode.c         | 61 ++++++++++++++++++++++++++++++++++++++++++++++--------
 fs/internal.h      |  2 +-
 fs/ocfs2/file.c    |  4 ++--
 fs/open.c          |  2 +-
 include/linux/fs.h |  2 +-
 5 files changed, 57 insertions(+), 14 deletions(-)

-- 
2.9.3

[toc] | [next] | [standalone]


#1570299

FromMichael Kerrisk <mtk.manpages@gmail.com>
Date2017-01-31 05:00 +0100
Message-ID<t5xLP-4aI-1@gated-at.bofh.it>
In reply to#1568832
[CC += linux-api@]

Andy, this is an API change!

On Sat, Jan 28, 2017 at 3:49 PM, Andy Lutomirski <luto@kernel.org> wrote:
> The kernel has some dangerous behavior involving the creation and
> modification of setgid executables.  These issues aren't kernel
> security bugs per se, but they have been used to turn various
> filesystem permission oddities into reliably privilege escalation
> exploits.
>
> See http://www.halfdog.net/Security/2015/SetgidDirectoryPrivilegeEscalation/
> for a nice writeup.
>
> Let's fix them for real.
>
> Changes from v1:
>  - Fix uninitialized variable issue (Willy, Ben)
>  - Also check current creds in should_remove_suid() (Ben)
>
> Andy Lutomirski (2):
>   fs: Check f_cred as well as of current's creds in should_remove_suid()
>   fs: Harden against open(..., O_CREAT, 02777) in a setgid directory
>
>  fs/inode.c         | 61 ++++++++++++++++++++++++++++++++++++++++++++++--------
>  fs/internal.h      |  2 +-
>  fs/ocfs2/file.c    |  4 ++--
>  fs/open.c          |  2 +-
>  include/linux/fs.h |  2 +-
>  5 files changed, 57 insertions(+), 14 deletions(-)
>
> --
> 2.9.3
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@kvack.org.  For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>



-- 
Michael Kerrisk Linux man-pages maintainer;
http://www.kernel.org/doc/man-pages/
Author of "The Linux Programming Interface", http://blog.man7.org/

[toc] | [prev] | [next] | [standalone]


#1570306

FromAndy Lutomirski <luto@amacapital.net>
Date2017-01-31 05:00 +0100
Message-ID<t5xLQ-4aI-21@gated-at.bofh.it>
In reply to#1570299
On Mon, Jan 30, 2017 at 7:49 PM, Michael Kerrisk <mtk.manpages@gmail.com> wrote:
> [CC += linux-api@]
>
> Andy, this is an API change!

Indeed.  I should be ashamed of myself!

>
> On Sat, Jan 28, 2017 at 3:49 PM, Andy Lutomirski <luto@kernel.org> wrote:
>> The kernel has some dangerous behavior involving the creation and
>> modification of setgid executables.  These issues aren't kernel
>> security bugs per se, but they have been used to turn various
>> filesystem permission oddities into reliably privilege escalation
>> exploits.
>>
>> See http://www.halfdog.net/Security/2015/SetgidDirectoryPrivilegeEscalation/
>> for a nice writeup.
>>
>> Let's fix them for real.
>>
>> Changes from v1:
>>  - Fix uninitialized variable issue (Willy, Ben)
>>  - Also check current creds in should_remove_suid() (Ben)
>>
>> Andy Lutomirski (2):
>>   fs: Check f_cred as well as of current's creds in should_remove_suid()
>>   fs: Harden against open(..., O_CREAT, 02777) in a setgid directory
>>
>>  fs/inode.c         | 61 ++++++++++++++++++++++++++++++++++++++++++++++--------
>>  fs/internal.h      |  2 +-
>>  fs/ocfs2/file.c    |  4 ++--
>>  fs/open.c          |  2 +-
>>  include/linux/fs.h |  2 +-
>>  5 files changed, 57 insertions(+), 14 deletions(-)
>>
>> --
>> 2.9.3
>>
>> --
>> To unsubscribe, send a message with 'unsubscribe linux-mm' in
>> the body to majordomo@kvack.org.  For more info on Linux MM,
>> see: http://www.linux-mm.org/ .
>> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
>
>
>
> --
> Michael Kerrisk Linux man-pages maintainer;
> http://www.kernel.org/doc/man-pages/
> Author of "The Linux Programming Interface", http://blog.man7.org/



-- 
Andy Lutomirski
AMA Capital Management, LLC

[toc] | [prev] | [standalone]


Back to top | Article view | linux.kernel


csiph-web