linux-kernel - [PATCH v6 3/6] x86, efi, kasan: #undef memset/memcpy/memmove per arch.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1442482692-6416-4-git-send-email-ryabinin.a.a@gmail.com>
Date:	Thu, 17 Sep 2015 12:38:09 +0300
From:	Andrey Ryabinin <ryabinin.a.a@...il.com>
To:	Will Deacon <will.deacon@....com>,
	Catalin Marinas <catalin.marinas@....com>,
	linux-arm-kernel@...ts.infradead.org
Cc:	Andrey Ryabinin <ryabinin.a.a@...il.com>,
	Matt Fleming <matt.fleming@...el.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
	linux-efi@...r.kernel.org, fengguang.wu@...el.com,
	Linus Walleij <linus.walleij@...aro.org>,
	Alexander Potapenko <glider@...gle.com>,
	Dmitry Vyukov <dvyukov@...gle.com>,
	Arnd Bergmann <arnd@...db.de>, linux-kernel@...r.kernel.org,
	David Keitel <dkeitel@...eaurora.org>, linux-mm@...ck.org,
	Alexey Klimov <klimov.linux@...il.com>,
	Yury <yury.norov@...il.com>,
	Andrey Konovalov <andreyknvl@...gle.com>
Subject: [PATCH v6 3/6] x86, efi, kasan: #undef memset/memcpy/memmove per arch.

In not-instrumented code KASAN replaces instrumented
memset/memcpy/memmove with not-instrumented analogues
__memset/__memcpy/__memove.
However, on x86 the EFI stub is not linked with the kernel.
It uses not-instrumented mem*() functions from
arch/x86/boot/compressed/string.c
So we don't replace them with __mem*() variants in EFI stub.

On ARM64 the EFI stub is linked with the kernel, so we should
replace mem*() functions with __mem*(), because the EFI stub
runs before KASAN sets up early shadow.

So let's move these #undef mem* into arch's asm/efi.h which is
also included by the EFI stub.

Also, this will fix the warning in 32-bit build reported by
kbuild test robot <fengguang.wu@...el.com>:
	efi-stub-helper.c:599:2: warning: implicit declaration of function 'memcpy'

Signed-off-by: Andrey Ryabinin <ryabinin.a.a@...il.com>
---
 arch/x86/include/asm/efi.h             | 12 ++++++++++++
 drivers/firmware/efi/libstub/efistub.h |  4 ----
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 155162e..6db2742 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -86,6 +86,18 @@ extern u64 asmlinkage efi_call(void *fp, ...);
 extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size,
 					u32 type, u64 attribute);
 
+/*
+ * CONFIG_KASAN may redefine memset to __memset.
+ * __memset function is present only in kernel binary.
+ * Since the EFI stub linked into a separate binary it
+ * doesn't have __memset(). So we should use standard
+ * memset from arch/x86/boot/compressed/string.c
+ * The same applies to memcpy and memmove.
+ */
+#undef memcpy
+#undef memset
+#undef memmove
+
 #endif /* CONFIG_X86_32 */
 
 extern struct efi_scratch efi_scratch;
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index e334a01..6b6548f 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -5,10 +5,6 @@
 /* error code which can't be mistaken for valid address */
 #define EFI_ERROR	(~0UL)
 
-#undef memcpy
-#undef memset
-#undef memmove
-
 void efi_char16_printk(efi_system_table_t *, efi_char16_t *);
 
 efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg, void *__image,
-- 
2.4.6

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/