linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Dmitry Vyukov <dvyukov@google.com>
To: linux-mm@kvack.org, akpm@linux-foundation.org
Cc: Dmitry Vyukov <dvyukov@google.com>,
	kasan-dev@googlegroups.com, Fengguang Wu <fengguang.wu@intel.com>,
	Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
	Andrey Ryabinin <aryabinin@virtuozzo.com>,
	Kees Cook <keescook@google.com>
Subject: [PATCH v2] KASAN: prohibit KASAN+STRUCTLEAK combination
Date: Thu, 19 Apr 2018 19:24:51 +0200	[thread overview]
Message-ID: <20180419172451.104700-1-dvyukov@google.com> (raw)

Currently STRUCTLEAK inserts initialization out of live scope of
variables from KASAN point of view. This leads to KASAN false
positive reports. Prohibit this combination for now.

Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: linux-mm@kvack.org
Cc: kasan-dev@googlegroups.com
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Kees Cook <keescook@google.com>

---

This combination leads to periodic confusion
and pointless debugging:

https://marc.info/?l=linux-kernel&m=151991367323082
https://marc.info/?l=linux-kernel&m=151992229326243
https://lkml.org/lkml/2017/11/30/33

Changes since v1:
 - replace KASAN with KASAN_EXTRA
   Only KASAN_EXTRA enables variable scope checking
---
 arch/Kconfig | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/Kconfig b/arch/Kconfig
index 8e0d665c8d53..75dd23acf133 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -464,6 +464,10 @@ config GCC_PLUGIN_LATENT_ENTROPY
 config GCC_PLUGIN_STRUCTLEAK
 	bool "Force initialization of variables containing userspace addresses"
 	depends on GCC_PLUGINS
+	# Currently STRUCTLEAK inserts initialization out of live scope of
+	# variables from KASAN point of view. This leads to KASAN false
+	# positive reports. Prohibit this combination for now.
+	depends on !KASAN_EXTRA
 	help
 	  This plugin zero-initializes any structures containing a
 	  __user attribute. This can prevent some classes of information
-- 
2.17.0.484.g0c8726318c-goog

             reply	other threads:[~2018-04-19 17:24 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-19 17:24 Dmitry Vyukov [this message]
2018-04-19 20:43 ` Kees Cook
2018-04-20  5:33   ` Dennis Zhou
2018-04-20  5:56     ` Dmitry Vyukov
2018-04-21 21:06       ` Dennis Zhou
2018-04-21 21:13         ` Kees Cook
2018-04-22  0:15           ` Dennis Zhou
2018-04-30 23:41 ` Kees Cook
2018-05-01  0:36   ` Dennis Zhou

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=20180419172451.104700-1-dvyukov@google.com \
    --to=dvyukov@google.com \
    --cc=akpm@linux-foundation.org \
    --cc=aryabinin@virtuozzo.com \
    --cc=fengguang.wu@intel.com \
    --cc=kasan-dev@googlegroups.com \
    --cc=keescook@google.com \
    --cc=linux-mm@kvack.org \
    --cc=sergey.senozhatsky.work@gmail.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