linux-kernel - [tip:x86/urgent] x86: disable stack-protector for __restore_processor

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 3 Apr 2009 17:33:42 GMT
From:	Joseph Cihula <joseph.cihula@...el.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, hpa@...or.com, mingo@...hat.com,
	arjan@...ux.intel.com, tj@...nel.org, tglx@...utronix.de,
	joseph.cihula@...el.com, mingo@...e.hu
Subject: [tip:x86/urgent] x86: disable stack-protector for __restore_processor_state()

Commit-ID:  1f23b77e09be10edb30eb03c1b03879083e3cc72
Gitweb:     http://git.kernel.org/tip/1f23b77e09be10edb30eb03c1b03879083e3cc72
Author:     Joseph Cihula <joseph.cihula@...el.com>
AuthorDate: Mon, 30 Mar 2009 14:03:01 -0700
Committer:  Ingo Molnar <mingo@...e.hu>
CommitDate: Fri, 3 Apr 2009 19:30:23 +0200

x86: disable stack-protector for __restore_processor_state()

The __restore_processor_state() fn restores %gs on resume from S3.  As
such, it cannot be protected by the stack-protector guard since %gs will
not be correct on function entry.

There are only a few other fns in this file and it should not negatively
impact kernel security that they will also have the stack-protector
guard removed (and so it's not worth moving them to another file).

Without this change, S3 resume on a kernel built with
CONFIG_CC_STACKPROTECTOR_ALL=y will fail.

Signed-off-by: Joseph Cihula <joseph.cihula@...el.com>
Cc: Arjan van de Ven <arjan@...ux.intel.com>
Cc: Tejun Heo <tj@...nel.org>
LKML-Reference: <49D13385.5060900@...el.com>
Signed-off-by: Ingo Molnar <mingo@...e.hu>


---
 arch/x86/power/Makefile |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/arch/x86/power/Makefile b/arch/x86/power/Makefile
index 9ff4d5b..58b32db 100644
--- a/arch/x86/power/Makefile
+++ b/arch/x86/power/Makefile
@@ -1,2 +1,7 @@
+# __restore_processor_state() restores %gs after S3 resume and so should not
+# itself be stack-protected
+nostackp := $(call cc-option, -fno-stack-protector)
+CFLAGS_cpu_$(BITS).o	:= $(nostackp)
+
 obj-$(CONFIG_PM_SLEEP)		+= cpu_$(BITS).o
 obj-$(CONFIG_HIBERNATION)	+= hibernate_$(BITS).o hibernate_asm_$(BITS).o
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/