[PATCH] arm64: kasan: instrument user memory access API
From: mark.rutland@arm.com (Mark Rutland)
Date: 2016-05-27 12:38:28
Also in:
linux-mm, lkml
Hi, On Thu, May 26, 2016 at 11:43:51AM -0700, Yang Shi wrote:
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.
Tested by test_kasan module.
I just gave this a go atop of the current HEAD (dc03c0f9d12d8528) on a
Juno R1 board. I hit the expected exceptions when using the test_kasan
module (once I remembered to rebuild it), and things seem to run
smoothly otherwise.
I don't see any built issues when !CONFIG_KASAN, and the patch itself
looks right to me.
So FWIW:
Acked-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
As an aside, it's a shame that each architecture has to duplicate this
logic, rather than having something in the generic code like:
static inline unsigned long __must_check
copy_from_user(void *to, const void __user *from, unsigned long n)
{
kasan_check_read(from, n);
arch_copy_from_user(to, from, n);
}
Thanks,
Mark.
quoted hunk ↗ jump to hunk
Signed-off-by: Yang Shi <redacted> --- arch/arm64/include/asm/uaccess.h | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 0685d74..ec352fa 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h@@ -23,6 +23,7 @@ */ #include <linux/string.h> #include <linux/thread_info.h> +#include <linux/kasan-checks.h> #include <asm/alternative.h> #include <asm/cpufeature.h>@@ -276,6 +277,8 @@ extern unsigned long __must_check __clear_user(void __user *addr, unsigned long 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); else /* security hole - plug it */@@ -285,6 +288,8 @@ static inline unsigned long __must_check copy_from_user(void *to, const void __u 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); return n;@@ -297,8 +302,17 @@ static inline unsigned long __must_check copy_in_user(void __user *to, const voi return n; } -#define __copy_to_user_inatomic __copy_to_user -#define __copy_from_user_inatomic __copy_from_user +static inline unsigned long __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n) +{ + kasan_check_read(from, n); + return __copy_to_user(to, from, n); +} + +static inline unsigned long __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n) +{ + kasan_check_write(to, n); + return __copy_from_user(to, from, n); +} static inline unsigned long __must_check clear_user(void __user *to, unsigned long n) {-- 2.0.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel at lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel