From: Jakub Kicinski <kuba@kernel.org>
To: Gal Pressman <gal@nvidia.com>
Cc: "David S. Miller" <davem@davemloft.net>, <netdev@vger.kernel.org>,
Vlad Buslov <vladbu@nvidia.com>
Subject: Re: [PATCH net] net: Fix undefined behavior in netdev name allocation
Date: Mon, 13 Nov 2023 23:09:02 -0500 [thread overview]
Message-ID: <20231113230902.7f342501@kernel.org> (raw)
In-Reply-To: <20231113083544.1685919-1-gal@nvidia.com>
On Mon, 13 Nov 2023 10:35:44 +0200 Gal Pressman wrote:
> Cited commit removed the strscpy() call and kept the snprintf() only.
>
> When allocating a netdev, 'res' and 'name' pointers are equal, but
> according to POSIX, if copying takes place between objects that overlap
> as a result of a call to sprintf() or snprintf(), the results are
> undefined.
>
> Add back the strscpy() and use 'buf' as an intermediate buffer.
It may be worth mentioning that it is fairly common to put the format
in dev->name before device is registered, IOW this condition takes
place a lot? IIUC once we cross into 3-digit IDs we may crash?
With that and the right fixes tag:
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Thanks!
--
pw-bot: cr
next prev parent reply other threads:[~2023-11-14 4:09 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-13 8:35 [PATCH net] net: Fix undefined behavior in netdev name allocation Gal Pressman
2023-11-13 9:53 ` Simon Horman
2023-11-13 14:01 ` Gal Pressman
2023-11-15 9:28 ` Simon Horman
2023-11-14 4:09 ` Jakub Kicinski [this message]
2023-11-14 4:12 ` Jakub Kicinski
2023-11-14 7:26 ` Gal Pressman
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