[v3 PATCH] arm64: kasan: instrument user memory access API
From: Yang Shi <hidden>
Date: 2016-06-08 22:08:59
Also in:
linux-mm, lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
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 <redacted>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Yang Shi <redacted>
---
v3:
Moved linux/kasan-checks.h before the other includes to keep them ordered
alphabetically as suggested by Mark.
Added Acked-by from Andrey Ryabinin and Reviewed-by/Tested-by from Mark.
v2:
Adopted the comment from Andrey and Mark to add kasan_check_read/write into
__copy_to/from_user.
arch/arm64/include/asm/uaccess.h | 25 +++++++++++++++++++++----
arch/arm64/kernel/arm64ksyms.c | 4 ++--
arch/arm64/lib/copy_from_user.S | 4 ++--
arch/arm64/lib/copy_to_user.S | 4 ++--
4 files changed, 27 insertions(+), 10 deletions(-)
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 0685d74..672d367 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>
@@ -269,15 +270,29 @@ do { \ -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;
@@ -285,8 +300,10 @@ 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); + n = __arch_copy_to_user(to, from, n); return n; }
diff --git a/arch/arm64/kernel/arm64ksyms.c b/arch/arm64/kernel/arm64ksyms.c
index 678f30b0..2dc4440 100644
--- a/arch/arm64/kernel/arm64ksyms.c
+++ b/arch/arm64/kernel/arm64ksyms.c@@ -34,8 +34,8 @@ EXPORT_SYMBOL(copy_page); EXPORT_SYMBOL(clear_page); /* user mem (segment) */ -EXPORT_SYMBOL(__copy_from_user); -EXPORT_SYMBOL(__copy_to_user); +EXPORT_SYMBOL(__arch_copy_from_user); +EXPORT_SYMBOL(__arch_copy_to_user); EXPORT_SYMBOL(__clear_user); EXPORT_SYMBOL(__copy_in_user);
diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S
index 17e8306..0b90497 100644
--- a/arch/arm64/lib/copy_from_user.S
+++ b/arch/arm64/lib/copy_from_user.S@@ -66,7 +66,7 @@ .endm end .req x5 -ENTRY(__copy_from_user) +ENTRY(__arch_copy_from_user) ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \ CONFIG_ARM64_PAN) add end, x0, x2
@@ -75,7 +75,7 @@ ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \ CONFIG_ARM64_PAN) mov x0, #0 // Nothing to copy ret -ENDPROC(__copy_from_user) +ENDPROC(__arch_copy_from_user) .section .fixup,"ax" .align 2
diff --git a/arch/arm64/lib/copy_to_user.S b/arch/arm64/lib/copy_to_user.S
index 21faae6..7a7efe2 100644
--- a/arch/arm64/lib/copy_to_user.S
+++ b/arch/arm64/lib/copy_to_user.S@@ -65,7 +65,7 @@ .endm end .req x5 -ENTRY(__copy_to_user) +ENTRY(__arch_copy_to_user) ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \ CONFIG_ARM64_PAN) add end, x0, x2
@@ -74,7 +74,7 @@ ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \ CONFIG_ARM64_PAN) mov x0, #0 ret -ENDPROC(__copy_to_user) +ENDPROC(__arch_copy_to_user) .section .fixup,"ax" .align 2
--
2.0.2