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| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-09-07 19:22:28 +0200 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-09-09 18:28:47 +0200 |
| commit | 8404663f81d212918ff85f493649a7991209fa04 (patch) | |
| tree | b695686fd2764914da245ef31649b1deb91ddafa /arch/arm/lib/putuser.S | |
| parent | ARM: 7526/1: traps: send SIGILL if get_user fails on undef handling path (diff) | |
| download | linux-8404663f81d212918ff85f493649a7991209fa04.tar.xz linux-8404663f81d212918ff85f493649a7991209fa04.zip | |
ARM: 7527/1: uaccess: explicitly check __user pointer when !CPU_USE_DOMAINS
The {get,put}_user macros don't perform range checking on the provided
__user address when !CPU_HAS_DOMAINS.
This patch reworks the out-of-line assembly accessors to check the user
address against a specified limit, returning -EFAULT if is is out of
range.
[will: changed get_user register allocation to match put_user]
[rmk: fixed building on older ARM architectures]
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/lib/putuser.S')
| -rw-r--r-- | arch/arm/lib/putuser.S | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm/lib/putuser.S b/arch/arm/lib/putuser.S index 7db25990c589..3d73dcb959b0 100644 --- a/arch/arm/lib/putuser.S +++ b/arch/arm/lib/putuser.S @@ -16,6 +16,7 @@ * __put_user_X * * Inputs: r0 contains the address + * r1 contains the address limit, which must be preserved * r2, r3 contains the value * Outputs: r0 is the error code * lr corrupted @@ -27,16 +28,19 @@ * Note also that it is intended that __put_user_bad is not global. */ #include <linux/linkage.h> +#include <asm/assembler.h> #include <asm/errno.h> #include <asm/domain.h> ENTRY(__put_user_1) + check_uaccess r0, 1, r1, ip, __put_user_bad 1: TUSER(strb) r2, [r0] mov r0, #0 mov pc, lr ENDPROC(__put_user_1) ENTRY(__put_user_2) + check_uaccess r0, 2, r1, ip, __put_user_bad mov ip, r2, lsr #8 #ifdef CONFIG_THUMB2_KERNEL #ifndef __ARMEB__ @@ -60,12 +64,14 @@ ENTRY(__put_user_2) ENDPROC(__put_user_2) ENTRY(__put_user_4) + check_uaccess r0, 4, r1, ip, __put_user_bad 4: TUSER(str) r2, [r0] mov r0, #0 mov pc, lr ENDPROC(__put_user_4) ENTRY(__put_user_8) + check_uaccess r0, 8, r1, ip, __put_user_bad #ifdef CONFIG_THUMB2_KERNEL 5: TUSER(str) r2, [r0] 6: TUSER(str) r3, [r0, #4] |