linux-kernel - [PATCH 4.19 091/323] x86: Increase exception stack sizes

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20211124115722.030562976@linuxfoundation.org>
Date:   Wed, 24 Nov 2021 12:54:41 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Michael Wang <yun.wang@...ux.alibaba.com>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.19 091/323] x86: Increase exception stack sizes

From: Peter Zijlstra <peterz@...radead.org>

[ Upstream commit 7fae4c24a2b84a66c7be399727aca11e7a888462 ]

It turns out that a single page of stack is trivial to overflow with
all the tracing gunk enabled. Raise the exception stacks to 2 pages,
which is still half the interrupt stacks, which are at 4 pages.

Reported-by: Michael Wang <yun.wang@...ux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Link: https://lkml.kernel.org/r/YUIO9Ye98S5Eb68w@hirez.programming.kicks-ass.net
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 arch/x86/include/asm/page_64_types.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h
index 0b6352aabbd3d..b16fb3e185134 100644
--- a/arch/x86/include/asm/page_64_types.h
+++ b/arch/x86/include/asm/page_64_types.h
@@ -20,7 +20,7 @@
 #define THREAD_SIZE  (PAGE_SIZE << THREAD_SIZE_ORDER)
 #define CURRENT_MASK (~(THREAD_SIZE - 1))
 
-#define EXCEPTION_STACK_ORDER (0 + KASAN_STACK_ORDER)
+#define EXCEPTION_STACK_ORDER (1 + KASAN_STACK_ORDER)
 #define EXCEPTION_STKSZ (PAGE_SIZE << EXCEPTION_STACK_ORDER)
 
 #define DEBUG_STACK_ORDER (EXCEPTION_STACK_ORDER + 1)
-- 
2.33.0