2024-06-10 16:14:06

by Ard Biesheuvel

Subject: [PATCH] crypto: arm/crc32 - add kCFI annotations to asm routines

From: Ard Biesheuvel <[email protected]>

The crc32/crc32c implementations using the scalar CRC32 instructions are
accessed via indirect calls, and so they must be annotated with type ids
in order to execute correctly when kCFI is enabled.

Cc: Kees Cook <[email protected]>
Cc: Linus Walleij <[email protected]>
Signed-off-by: Ard Biesheuvel <[email protected]>
---
arch/arm/crypto/crc32-ce-core.S | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/arch/arm/crypto/crc32-ce-core.S b/arch/arm/crypto/crc32-ce-core.S
index 3f13a76b9066..88f9edf94e95 100644
--- a/arch/arm/crypto/crc32-ce-core.S
+++ b/arch/arm/crypto/crc32-ce-core.S
@@ -48,6 +48,7 @@
*/

#include <linux/linkage.h>
+#include <linux/cfi_types.h>
#include <asm/assembler.h>

.text
@@ -123,11 +124,12 @@
* uint crc32_pmull_le(unsigned char const *buffer,
* size_t len, uint crc32)
*/
-ENTRY(crc32_pmull_le)
+SYM_FUNC_START(crc32_pmull_le)
adr r3, .Lcrc32_constants
b 0f
+SYM_FUNC_END(crc32_pmull_le)

-ENTRY(crc32c_pmull_le)
+SYM_FUNC_START(crc32c_pmull_le)
adr r3, .Lcrc32c_constants

0: bic LEN, LEN, #15
@@ -236,8 +238,7 @@ fold_64:
vmov r0, s5

bx lr
-ENDPROC(crc32_pmull_le)
-ENDPROC(crc32c_pmull_le)
+SYM_FUNC_END(crc32c_pmull_le)

.macro __crc32, c
subs ip, r2, #8
@@ -296,11 +297,11 @@ ARM_BE8(rev16 r3, r3 )
.endm

.align 5
-ENTRY(crc32_armv8_le)
+SYM_TYPED_FUNC_START(crc32_armv8_le)
__crc32
-ENDPROC(crc32_armv8_le)
+SYM_FUNC_END(crc32_armv8_le)

.align 5
-ENTRY(crc32c_armv8_le)
+SYM_TYPED_FUNC_START(crc32c_armv8_le)
__crc32 c
-ENDPROC(crc32c_armv8_le)
+SYM_FUNC_END(crc32c_armv8_le)
--
2.45.2.505.gda0bf45e8d-goog

2024-06-10 16:55:51

by Kees Cook

Subject: Re: [PATCH] crypto: arm/crc32 - add kCFI annotations to asm routines

On Mon, Jun 10, 2024 at 05:26:39PM +0200, Ard Biesheuvel wrote:
> From: Ard Biesheuvel <[email protected]>
>
> The crc32/crc32c implementations using the scalar CRC32 instructions are
> accessed via indirect calls, and so they must be annotated with type ids
> in order to execute correctly when kCFI is enabled.
>
> Cc: Kees Cook <[email protected]>
> Cc: Linus Walleij <[email protected]>
> Signed-off-by: Ard Biesheuvel <[email protected]>

Reviewed-by: Kees Cook <[email protected]>

--
Kees Cook

2024-06-11 21:10:40

by Linus Walleij

Subject: Re: [PATCH] crypto: arm/crc32 - add kCFI annotations to asm routines

On Mon, Jun 10, 2024 at 5:26 PM Ard Biesheuvel <[email protected]> wrote:

> From: Ard Biesheuvel <[email protected]>
>
> The crc32/crc32c implementations using the scalar CRC32 instructions are
> accessed via indirect calls, and so they must be annotated with type ids
> in order to execute correctly when kCFI is enabled.
>
> Cc: Kees Cook <[email protected]>
> Cc: Linus Walleij <[email protected]>
> Signed-off-by: Ard Biesheuvel <[email protected]>

Fixes: 1a4fec49efe5 ("ARM: 9392/2: Support CLANG CFI")
Reviewed-by: Linus Walleij <[email protected]>

Thanks for helping to iron out the rough corners on these patches!

Yours,
Linus Walleij