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From: Jason Xing <kerneljasonxing@gmail.com>
Date: Wed, 6 Mar 2024 19:56:32 +0800
Message-ID: <CAL+tcoBSkBG0SDnjDOzjqzpSFphrE-_Qyw_DcdcebHcRCU3xgw@mail.gmail.com>
Subject: Re: [PATCH net-next] tcp: fix incorrect parameter validation in the
 do_tcp_getsockopt() function
To: Paolo Abeni <pabeni@redhat.com>
Cc: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>, Eric Dumazet <edumazet@google.com>, 
	"David S. Miller" <davem@davemloft.net>, David Ahern <dsahern@kernel.org>, 
	Jakub Kicinski <kuba@kernel.org>, "netdev@vger.kernel.org" <netdev@vger.kernel.org>, 
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, 
	"lvc-project@linuxtesting.org" <lvc-project@linuxtesting.org>
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Hello Paolo,

On Wed, Mar 6, 2024 at 7:36=E2=80=AFPM Paolo Abeni <pabeni@redhat.com> wrot=
e:
>
> On Wed, 2024-03-06 at 09:57 +0000, Gavrilov Ilia wrote:
> > The 'len' variable can't be negative because all 'min_t' parameters
> > cast to unsigned int, and then the minimum one is chosen.
>
> The above is incorrect, as the 'len' variable is a signed integer

The 'len' variable should be converted to the non-negative value as
this sentence:

len =3D min_t(unsigned int, len, sizeof(int));

See the comments of min_t(): return minimum of two values, using the
specified type.

After executing the above code, it doesn't make sense to test if 'len
< 0', I think.

Thanks,
Jason

>
>
> The same applies to the following patches.
>
> Cheers,
>
> Paolo
>
>