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From: Eric Dumazet <edumazet@google.com>
Date: Mon, 4 Mar 2024 06:12:11 +0100
Message-ID: <CANn89i+cfMWX_ybtP-VHX7PgLT-mwuUkYMuqsnUwZ3jki8oTcA@mail.gmail.com>
Subject: Re: [PATCH] net/netrom: fix uninit-value in nr_route_frame
To: Edward Adam Davis <eadavis@qq.com>
Cc: davem@davemloft.net, kuba@kernel.org, linux-hams@vger.kernel.org, 
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, 
	ralf@linux-mips.org, syzbot+f770ce3566e60e5573ac@syzkaller.appspotmail.com, 
	syzkaller-bugs@googlegroups.com
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On Mon, Mar 4, 2024 at 6:05=E2=80=AFAM Edward Adam Davis <eadavis@qq.com> w=
rote:
>
> [Syzbot reported]
>
> [Fix]
> Let's clear all skb data at alloc time.
>
> Reported-and-tested-by: syzbot+f770ce3566e60e5573ac@syzkaller.appspotmail=
com
> Signed-off-by: Edward Adam Davis <eadavis@qq.com>
> ---
>  net/core/skbuff.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> index edbbef563d4d..5ca5a608daec 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -656,6 +656,7 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t =
gfp_mask,
>          * to allow max possible filling before reallocation.
>          */
>         prefetchw(data + SKB_WITH_OVERHEAD(size));
> +       memset(data, 0, size);


We are not going to accept such a change, for obvious performance reasons.

Instead, please fix net/netrom/nr_route.c

Thank you.