Messages in this thread Patch in this message | | | Date | Wed, 24 May 2017 12:34:46 -0400 | From | Rik van Riel <> | Subject | [PATCH 5/5] sh64: ascii armor the sh64 boot init stack canary |
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Use the ascii-armor canary to prevent unterminated C string overflows from being able to successfully overwrite the canary, even if they somehow obtain the canary value.
Inspired by execshield ascii-armor and Daniel Micay's linux-hardened tree.
Signed-off-by: Rik van Riel <riel@redhat.com> --- arch/sh/include/asm/stackprotector.h | 1 + 1 file changed, 1 insertion(+)
diff --git a/arch/sh/include/asm/stackprotector.h b/arch/sh/include/asm/stackprotector.h index d9df3a76847c..141515a43b78 100644 --- a/arch/sh/include/asm/stackprotector.h +++ b/arch/sh/include/asm/stackprotector.h @@ -19,6 +19,7 @@ static __always_inline void boot_init_stack_canary(void) /* Try to get a semi random initial value. */ get_random_bytes(&canary, sizeof(canary)); canary ^= LINUX_VERSION_CODE; + canary &= CANARY_MASK; current->stack_canary = canary; __stack_chk_guard = current->stack_canary;
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