diff options
| author | Rik van Riel <[email protected]> | 2017-07-12 14:36:23 -0700 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2017-07-12 16:26:03 -0700 |
| commit | bf9eb5443844e288b73f7963dfc67a0d2fbc3849 (patch) | |
| tree | 1891d6e309923092a4f6bd8bede3ae37ccb50be6 | |
| parent | 7cd815bce828220deffd1654265f0ef891567774 (diff) | |
x86: ascii armor the x86_64 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/[email protected]
Signed-off-by: Rik van Riel <[email protected]>
Acked-by: Kees Cook <[email protected]>
Cc: Daniel Micay <[email protected]>
Cc: "Theodore Ts'o" <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
| -rw-r--r-- | arch/x86/include/asm/stackprotector.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h index dcbd9bcce714..8abedf1d650e 100644 --- a/arch/x86/include/asm/stackprotector.h +++ b/arch/x86/include/asm/stackprotector.h @@ -74,6 +74,7 @@ static __always_inline void boot_init_stack_canary(void) get_random_bytes(&canary, sizeof(canary)); tsc = rdtsc(); canary += tsc + (tsc << 32UL); + canary &= CANARY_MASK; current->stack_canary = canary; #ifdef CONFIG_X86_64 |