From: riel@redhat.com
To: linux-kernel@vger.kernel.org
Cc: danielmicay@gmail.com, tytso@mit.edu, keescook@chromium.org,
hpa@zytor.com, luto@amacapital.net, mingo@kernel.org,
x86@kernel.org, linux-arm-kernel@lists.infradead.org,
catalin.marinas@arm.com, linux-sh@vger.kernel.org,
ysato@users.sourceforge.jp, kernel-hardening@lists.openwall.com
Subject: [PATCH 4/5] arm64: ascii armor the arm64 boot init stack canary
Date: Wed, 24 May 2017 15:57:50 +0000 [thread overview]
Message-ID: <20170524155751.424-5-riel@redhat.com> (raw)
In-Reply-To: <20170524155751.424-1-riel@redhat.com>
From: Rik van Riel <riel@redhat.com>
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/arm64/include/asm/stackprotector.h | 1 +
1 file changed, 1 insertion(+)
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;
--
2.9.3
next prev parent reply other threads:[~2017-05-24 15:57 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-24 15:57 [PATCH v2 0/5] stackprotector: ascii armor the stack canary riel
2017-05-24 15:57 ` [PATCH 1/5] random,stackprotect: introduce get_random_canary function riel
2017-05-24 16:15 ` Kees Cook
2017-05-24 15:57 ` [PATCH 2/5] fork,random: use get_random_canary to set tsk->stack_canary riel
2017-05-24 16:16 ` Kees Cook
2017-05-24 15:57 ` [PATCH 3/5] x86: ascii armor the x86_64 boot init stack canary riel
2017-05-24 16:16 ` Kees Cook
2017-05-24 15:57 ` riel [this message]
2017-05-24 16:16 ` [PATCH 4/5] arm64: ascii armor the arm64 " Kees Cook
2017-05-24 15:57 ` [PATCH 5/5] sh64: ascii armor the sh64 " riel
2017-05-24 16:34 ` Rik van Riel
2017-05-24 16:35 ` Kees Cook
2017-09-19 17:16 ` [kernel-hardening] [PATCH v2 0/5] stackprotector: ascii armor the " Solar Designer
2017-09-19 20:22 ` Kees Cook
2017-09-19 21:10 ` Daniel Micay
2017-09-20 11:18 ` Yann Droneaud
2017-09-20 15:03 ` Solar Designer
-- strict thread matches above, loose matches on Subject: below --
2017-05-19 21:26 riel
2017-05-19 21:26 ` [PATCH 4/5] arm64: ascii armor the arm64 boot init " riel
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