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From: Kees Cook <keescook@chromium.org>
To: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Kees Cook <keescook@chromium.org>, Laura Abbott <labbott@redhat.com>,
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        Lai Jiangshan <jiangshanlai@gmail.com>,
        "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Michael Ellerman <mpe@ellerman.id.au>,
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        Andrey Ryabinin <aryabinin@virtuozzo.com>,
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        Dmitry Vyukov <dvyukov@google.com>, linux-kernel@vger.kernel.org,
        kernel-hardening@lists.openwall.com
Subject: [PATCH v3 0/5] bug: Provide toggle for BUG on data corruption
Date: Wed, 17 Aug 2016 14:42:07 -0700
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This adds CONFIG_BUG_ON_DATA_CORRUPTION to trigger BUG()s when the kernel
encounters unexpected data structure integrity as currently detected
with CONFIG_DEBUG_LIST.

Specifically list operations have been a target for widening flaws to gain
"write anywhere" primitives for attackers, so this also consolidates the
debug checking to avoid code and check duplication (e.g. RCU list debug
was missing a check that got added to regular list debug). It also stops
manipulations when corruption is detected, since worsening the corruption
makes no sense. (Really, everyone should build with CONFIG_DEBUG_LIST
since the checks are so inexpensive.)

This is mostly a refactoring of similar code from PaX and Grsecurity,
along with MSM kernel changes by Syed Rameez Mustafa.

Along with the patches is a new lkdtm test to validate that setting
CONFIG_DEBUG_LIST actually does what is desired.

Thanks,

-Kees

v3:
- fix MSM attribution, sboyd
- use pr_err, joe

v2:
- consolidate printk/WARN/BUG/return logic into a CONFIG-specific macro
- drop non-list BUGs, labbott