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Message-ID: <4067fb33-2172-b132-e8c4-0ba21c31b42a@embeddedor.com>
Date:   Sun, 17 Sep 2023 13:59:26 -0600
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Subject: Re: [PATCH v2][next] RDMA/core: Use size_{add,mul}() in calls to
 struct_size()
Content-Language: en-US
To:     Leon Romanovsky <leon@kernel.org>
Cc:     Kees Cook <keescook@chromium.org>,
        "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        Jason Gunthorpe <jgg@ziepe.ca>, linux-rdma@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
References: <ZP+if342EMhModzZ@work> <202309142029.D432EEB8C@keescook>
 <2594c7ff-0301-90aa-d48c-6b4d674f850e@embeddedor.com>
 <20230918104938.GD13757@unreal>
From:   "Gustavo A. R. Silva" <gustavo@embeddedor.com>
In-Reply-To: <20230918104938.GD13757@unreal>
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On 9/18/23 04:49, Leon Romanovsky wrote:
> On Fri, Sep 15, 2023 at 12:06:21PM -0600, Gustavo A. R. Silva wrote:
>>
>>
>> On 9/14/23 21:29, Kees Cook wrote:
>>> On Mon, Sep 11, 2023 at 05:27:59PM -0600, Gustavo A. R. Silva wrote:
>>>> Harden calls to struct_size() with size_add() and size_mul().
>>>
>>> Specifically, make sure that open-coded arithmetic cannot cause an
>>> overflow/wraparound. (i.e. it will stay saturated at SIZE_MAX.)
>>
>> Yep; I have another patch where I explain this in similar terms.
>>
>> I'll send it, shortly.
> 
> You missed other places with similar arithmetic.
> drivers/infiniband/core/device.c:       pdata_rcu = kzalloc(struct_size(pdata_rcu, pdata,
> drivers/infiniband/core/device.c-                                       rdma_end_port(device) + 1),
> drivers/infiniband/core/device.c-                           GFP_KERNEL);
> 
> drivers/infiniband/core/sa_query.c:     sa_dev = kzalloc(struct_size(sa_dev, port, e - s + 1), GFP_KERNEL);
> drivers/infiniband/core/user_mad.c:     umad_dev = kzalloc(struct_size(umad_dev, ports, e - s + 1), GFP_KERNEL);

I haven't sent all my patches.

--
Gustavo