From: Kees Cook <keescook@chromium.org>
Date: Thu, 7 Jul 2016 18:38:39 +0000 (-0700)
Subject: s390/uaccess: Enable hardened usercopy
X-Git-Tag: firefly_0821_release~176^2~4^2~33^2~2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=41e3ca9b2fc29b61dda146c9ba79736ba11e28e8;p=firefly-linux-kernel-4.4.55.git

s390/uaccess: Enable hardened usercopy

Enables CONFIG_HARDENED_USERCOPY checks on s390.

Signed-off-by: Kees Cook <keescook@chromium.org>
(cherry picked from commit 97433ea4fda62349bfa42089455593cbcb57e06c)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
---

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 3a55f493c7da..60530fd93d6d 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -117,6 +117,7 @@ config S390
 	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_EARLY_PFN_TO_NID
+	select HAVE_ARCH_HARDENED_USERCOPY
 	select HAVE_ARCH_JUMP_LABEL
 	select HAVE_ARCH_SECCOMP_FILTER
 	select HAVE_ARCH_SOFT_DIRTY
diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c
index ae4de559e3a0..6986c20166f0 100644
--- a/arch/s390/lib/uaccess.c
+++ b/arch/s390/lib/uaccess.c
@@ -104,6 +104,7 @@ static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
 
 unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
 {
+	check_object_size(to, n, false);
 	if (static_branch_likely(&have_mvcos))
 		return copy_from_user_mvcos(to, from, n);
 	return copy_from_user_mvcp(to, from, n);
@@ -177,6 +178,7 @@ static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
 
 unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
 {
+	check_object_size(from, n, true);
 	if (static_branch_likely(&have_mvcos))
 		return copy_to_user_mvcos(to, from, n);
 	return copy_to_user_mvcs(to, from, n);