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Date: Wed, 22 Jan 2025 06:24:27 -0800
From: Jakub Kicinski <kuba@kernel.org>
To: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Thomas Graf <tgraf@suug.ch>, "David S. Miller" <davem@davemloft.net>,
 Eric Dumazet <edumazet@google.com>, Paolo Abeni <pabeni@redhat.com>, Simon
 Horman <horms@kernel.org>, netdev@vger.kernel.org,
 linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [PATCH net] net: netlink: prevent potential integer overflow in
 nlmsg_new()
Message-ID: <20250122062427.2776d926@kernel.org>
In-Reply-To: <58023f9e-555e-48db-9822-283c2c1f6d0e@stanley.mountain>
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On Wed, 22 Jan 2025 16:49:17 +0300 Dan Carpenter wrote:
> The "payload" variable is type size_t, however the nlmsg_total_size()
> function will a few bytes to it and then truncate the result to type
> int.  That means that if "payload" is more than UINT_MAX the alloc_skb()
> function might allocate a buffer which is smaller than intended.

Is there a bug, or is this theoretical?