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Date:   Tue, 19 Sep 2023 10:37:15 +0300
From:   Leon Romanovsky <leon@kernel.org>
To:     "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc:     Jason Gunthorpe <jgg@ziepe.ca>, Parav Pandit <parav@mellanox.com>,
        Jack Morgenstein <jackm@mellanox.com>,
        "Gustavo A. R. Silva" <gustavo@embeddedor.com>,
        linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org
Subject: Re: [PATCH v3][next] RDMA/core: Use size_{add,sub,mul}() in calls to
 struct_size()
Message-ID: <20230919073715.GC4494@unreal>
References: <ZQdt4NsJFwwOYxUR@work>
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On Sun, Sep 17, 2023 at 03:21:36PM -0600, Gustavo A. R. Silva wrote:
> If, for any reason, the open-coded arithmetic causes a wraparound,

The thing is that it doesn't.

> the protection that `struct_size()` provides against potential integer
> overflows is defeated. Fix this by hardening calls to `struct_size()`
> with `size_add()`, `size_sub()` and `size_mul()`.
> 
> Fixes: 467f432a521a ("RDMA/core: Split port and device counter sysfs attributes")
> Fixes: a4676388e2e2 ("RDMA/core: Simplify how the gid_attrs sysfs is created")
> Fixes: e9dd5daf884c ("IB/umad: Refactor code to use cdev_device_add()")
> Fixes: 324e227ea7c9 ("RDMA/device: Add ib_device_get_by_netdev()")
> Fixes: 5aad26a7eac5 ("IB/core: Use struct_size() in kzalloc()")
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
> Changes in v3:
>  - Include changes to other files in drivers/infiniband/core/
>  - Update changelog text with a more descriptive argument for the
>    changes.
>  - Add more `Fixes:` tags.

I don't think that any of these Fixes are necessary, as nothing wrong
in the code you changed.

Thanks