From: David Howells <dhowells@redhat.com>
To: Len Baker <len.baker@gmx.com>
Cc: dhowells@redhat.com, Marc Dionne <marc.dionne@auristor.com>,
"Gustavo A. R. Silva" <gustavoars@kernel.org>,
Kees Cook <keescook@chromium.org>,
linux-afs@lists.infradead.org, linux-hardening@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] afs: Prefer struct_size over open coded arithmetic
Date: Tue, 02 Nov 2021 09:44:57 +0000 [thread overview]
Message-ID: <4028805.1635846297@warthog.procyon.org.uk> (raw)
In-Reply-To: <20210919094432.30510-1-len.baker@gmx.com>
Len Baker <len.baker@gmx.com> wrote:
> As noted in the "Deprecated Interfaces, Language Features, Attributes,
> and Conventions" documentation [1], size calculations (especially
> multiplication) should not be performed in memory allocator (or similar)
> function arguments due to the risk of them overflowing. This could lead
> to values wrapping around and a smaller allocation being made than the
> caller was expecting. Using those allocations could lead to linear
> overflows of heap memory and other misbehaviors.
>
> So, use the struct_size() helper to do the arithmetic instead of the
> argument "size + size * count" in the kzalloc() function.
>
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
>
> Signed-off-by: Len Baker <len.baker@gmx.com>
Acked-by: David Howells <dhowells@redhat.com>
prev parent reply other threads:[~2021-11-02 9:45 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-19 9:44 [PATCH] afs: Prefer struct_size over open coded arithmetic Len Baker
2021-09-21 0:09 ` Gustavo A. R. Silva
2021-10-20 23:26 ` Gustavo A. R. Silva
2021-11-02 9:44 ` David Howells [this message]
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