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From:   Daniel Micay <danielmicay@gmail.com>
Date:   Mon, 28 Feb 2022 10:15:59 -0500
Message-ID: <CA+DvKQ+bp7Y7gmaVhacjv9uF6Ar-o4tet872h4Q8RPYPJjcJQA@mail.gmail.com>
Subject: Re: [PATCH] mm: Handle ksize() vs __alloc_size by forgetting size
To:     Marco Elver <elver@google.com>
Cc:     Kees Cook <keescook@chromium.org>, llvm@lists.linux.dev,
        Pekka Enberg <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Vlastimil Babka <vbabka@suse.cz>, linux-mm@kvack.org,
        stable@vger.kernel.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Christoph Lameter <cl@linux.com>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
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Precedence: bulk

Looked through them and nearly all seem easy to replace.

By the way, the call to ksize in arch/x86/kernel/cpu/microcode/amd.c
doesn't look right. It allocates the memory with kmemdup. I don't see
how it can assume that the padding is zero, and that seems to be a
requirement since it zeroes the destination before copying to it.
Seems far more reasonable to add a field with the size.