public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Tycho Andersen <tycho@docker.com>
To: Kees Cook <keescook@chromium.org>,
	James Morris <james.l.morris@oracle.com>
Cc: linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org, Tycho Andersen <tycho@docker.com>,
	"Serge E. Hallyn" <serge@hallyn.com>
Subject: [PATCH] security/Kconfig: further restrict HARDENED_USERCOPY
Date: Thu,  9 Mar 2017 09:29:21 -0800	[thread overview]
Message-ID: <1489080561-30786-1-git-send-email-tycho@docker.com> (raw)

It doesn't make sense to have HARDENED_USERCOPY when either /dev/kmem is
enabled or /dev/mem can be used to read kernel memory.

v2: add !MMU depend as well

Signed-off-by: Tycho Andersen <tycho@docker.com>
CC: Kees Cook <keescook@chromium.org>
CC: "Serge E. Hallyn" <serge@hallyn.com>
CC: James Morris <james.l.morris@oracle.com>
---
 security/Kconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/security/Kconfig b/security/Kconfig
index 3ff1bf9..aeabd40 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -142,6 +142,8 @@ config HARDENED_USERCOPY
 	bool "Harden memory copies between kernel and userspace"
 	depends on HAVE_ARCH_HARDENED_USERCOPY
 	depends on HAVE_HARDENED_USERCOPY_ALLOCATOR
+	depends on !DEVKMEM
+	depends on !ARCH_HAS_DEVMEM_IS_ALLOWED || STRICT_DEVMEM || !MMU
 	select BUG
 	help
 	  This option checks for obviously wrong memory regions when
-- 
2.7.4

             reply	other threads:[~2017-03-09 17:31 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-09 17:29 Tycho Andersen [this message]
2017-03-09 19:18 ` [PATCH] security/Kconfig: further restrict HARDENED_USERCOPY Kees Cook

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1489080561-30786-1-git-send-email-tycho@docker.com \
    --to=tycho@docker.com \
    --cc=james.l.morris@oracle.com \
    --cc=keescook@chromium.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=serge@hallyn.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox