arm64: kasan: instrument user memory access API
The upstream commit 1771c6e1a567ea0ba2cccc0a4ffe68a1419fd8ef
("x86/kasan: instrument user memory access API") added KASAN instrument to
x86 user memory access API, so added such instrument to ARM64 too.
Define __copy_to/from_user in C in order to add kasan_check_read/write call,
rename assembly implementation to __arch_copy_to/from_user.
Tested by test_kasan module.
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 9e397a5..5e834d1 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -21,6 +21,7 @@
/*
* User space memory access functions
*/
+#include <linux/kasan-checks.h>
#include <linux/string.h>
#include <linux/thread_info.h>
@@ -256,15 +257,29 @@
-EFAULT; \
})
-extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n);
-extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n);
+extern unsigned long __must_check __arch_copy_from_user(void *to, const void __user *from, unsigned long n);
+extern unsigned long __must_check __arch_copy_to_user(void __user *to, const void *from, unsigned long n);
extern unsigned long __must_check __copy_in_user(void __user *to, const void __user *from, unsigned long n);
extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
+static inline unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+ kasan_check_write(to, n);
+ return __arch_copy_from_user(to, from, n);
+}
+
+static inline unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+ kasan_check_read(from, n);
+ return __arch_copy_to_user(to, from, n);
+}
+
static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
{
+ kasan_check_write(to, n);
+
if (access_ok(VERIFY_READ, from, n))
- n = __copy_from_user(to, from, n);
+ n = __arch_copy_from_user(to, from, n);
else /* security hole - plug it */
memset(to, 0, n);
return n;
@@ -272,8 +287,10 @@
static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
{
+ kasan_check_read(from, n);
+
if (access_ok(VERIFY_WRITE, to, n))
- n = __copy_to_user(to, from, n);
+ n = __arch_copy_to_user(to, from, n);
return n;
}