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author | Rik van Riel <riel@redhat.com> | 2017-07-12 14:36:29 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-07-12 16:26:03 -0700 |
commit | 2c8340eda45cee1784f7b29e6d7dcc740ea3d02a (patch) | |
tree | a91096df0d2df5605cb0cfa86d1e2fffecbca9a6 /arch/sh | |
parent | d21f54988bb2927341757d42152440c3abcae4eb (diff) | |
download | lwn-2c8340eda45cee1784f7b29e6d7dcc740ea3d02a.tar.gz lwn-2c8340eda45cee1784f7b29e6d7dcc740ea3d02a.zip |
sh64: ascii armor the sh64 boot init stack canary
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.
Link: http://lkml.kernel.org/r/20170524123446.78510066@annuminas.surriel.com
Signed-off-by: Rik van Riel <riel@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/sh')
-rw-r--r-- | arch/sh/include/asm/stackprotector.h | 1 |
1 files changed, 1 insertions, 0 deletions
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; |