diff options
| author | Rik van Riel <riel@redhat.com> | 2017-05-26 11:32:09 +1000 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2017-05-29 09:22:49 +1000 |
| commit | 083eff5b6c3a9edada043fcc7adf495f0340bd7b (patch) | |
| tree | 752b49eb82fcdb1b9b16761b0dc60565ec9312ea | |
| parent | d2689c9c74d64eb8882f5ea5fc5a7fb30c169bed (diff) | |
arm64: ascii armor the arm64 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/20170524155751.424-5-riel@redhat.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>
| -rw-r--r-- | arch/arm64/include/asm/stackprotector.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/stackprotector.h b/arch/arm64/include/asm/stackprotector.h index fe5e287dc56b..b86a0865ddf1 100644 --- a/arch/arm64/include/asm/stackprotector.h +++ b/arch/arm64/include/asm/stackprotector.h @@ -30,6 +30,7 @@ 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; |