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authorKees Cook <keescook@chromium.org>2017-02-16 01:43:58 +0100
committerRussell King <rmk+kernel@armlinux.org.uk>2017-02-16 15:58:31 +0000
commit32b143637e8180f5d5cea54320c769210dea4f19 (patch)
tree636eec0a91ac1dfffdd9208539633cc8ccb0417a
parent228dbbfb5d77f8e047b2a1d78da14b7158433027 (diff)
downloadlinux-stericsson-32b143637e8180f5d5cea54320c769210dea4f19.tar.gz
ARM: 8657/1: uaccess: consistently check object sizes
In commit 76624175dcae ("arm64: uaccess: consistently check object sizes"), the object size checks are moved outside the access_ok() so that bad destinations are detected before hitting the "memset(dest, 0, size)" in the copy_from_user() failure path. This makes the same change for arm, with attention given to possibly extracting the uaccess routines into a common header file for all architectures in the future. Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
-rw-r--r--arch/arm/include/asm/uaccess.h44
1 files changed, 32 insertions, 12 deletions
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
index 1f59ea051bab..b7e0125c0bbf 100644
--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h
@@ -478,11 +478,10 @@ extern unsigned long __must_check
arm_copy_from_user(void *to, const void __user *from, unsigned long n);
static inline unsigned long __must_check
-__copy_from_user(void *to, const void __user *from, unsigned long n)
+__arch_copy_from_user(void *to, const void __user *from, unsigned long n)
{
unsigned int __ua_flags;
- check_object_size(to, n, false);
__ua_flags = uaccess_save_and_enable();
n = arm_copy_from_user(to, from, n);
uaccess_restore(__ua_flags);
@@ -495,18 +494,15 @@ extern unsigned long __must_check
__copy_to_user_std(void __user *to, const void *from, unsigned long n);
static inline unsigned long __must_check
-__copy_to_user(void __user *to, const void *from, unsigned long n)
+__arch_copy_to_user(void __user *to, const void *from, unsigned long n)
{
#ifndef CONFIG_UACCESS_WITH_MEMCPY
unsigned int __ua_flags;
-
- check_object_size(from, n, true);
__ua_flags = uaccess_save_and_enable();
n = arm_copy_to_user(to, from, n);
uaccess_restore(__ua_flags);
return n;
#else
- check_object_size(from, n, true);
return arm_copy_to_user(to, from, n);
#endif
}
@@ -526,25 +522,49 @@ __clear_user(void __user *addr, unsigned long n)
}
#else
-#define __copy_from_user(to, from, n) (memcpy(to, (void __force *)from, n), 0)
-#define __copy_to_user(to, from, n) (memcpy((void __force *)to, from, n), 0)
+#define __arch_copy_from_user(to, from, n) \
+ (memcpy(to, (void __force *)from, n), 0)
+#define __arch_copy_to_user(to, from, n) \
+ (memcpy((void __force *)to, from, n), 0)
#define __clear_user(addr, n) (memset((void __force *)addr, 0, n), 0)
#endif
-static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
+static inline unsigned long __must_check
+__copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+ check_object_size(to, n, false);
+ return __arch_copy_from_user(to, from, n);
+}
+
+static inline unsigned long __must_check
+copy_from_user(void *to, const void __user *from, unsigned long n)
{
unsigned long res = n;
+
+ check_object_size(to, n, false);
+
if (likely(access_ok(VERIFY_READ, from, n)))
- res = __copy_from_user(to, from, n);
+ res = __arch_copy_from_user(to, from, n);
if (unlikely(res))
memset(to + (n - res), 0, res);
return res;
}
-static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
+static inline unsigned long __must_check
+__copy_to_user(void __user *to, const void *from, unsigned long n)
{
+ check_object_size(from, n, true);
+
+ return __arch_copy_to_user(to, from, n);
+}
+
+static inline unsigned long __must_check
+copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+ check_object_size(from, n, true);
+
if (access_ok(VERIFY_WRITE, to, n))
- n = __copy_to_user(to, from, n);
+ n = __arch_copy_to_user(to, from, n);
return n;
}