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Date:   Fri, 23 Jul 2021 19:52:53 +0300
From:   Pavel Skripkin <paskripkin@gmail.com>
To:     Xin Long <lucien.xin@gmail.com>
Cc:     syzbot <syzbot+e6741b97d5552f97c24d@syzkaller.appspotmail.com>,
        davem <davem@davemloft.net>, devicetree@vger.kernel.org,
        frowand.list@gmail.com,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jon Maloy <jmaloy@redhat.com>,
        Jakub Kicinski <kuba@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        network dev <netdev@vger.kernel.org>, rafael@kernel.org,
        robh+dt@kernel.org, robh@kernel.org,
        syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
        tipc-discussion@lists.sourceforge.net,
        Ying Xue <ying.xue@windriver.com>
Subject: Re: [syzbot] KASAN: use-after-free Read in tipc_recvmsg
Message-ID: <20210723195253.56ef4ee3@gmail.com>
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        <20210723193611.746e7071@gmail.com>
        <CADvbK_dkv-DDt_VSSn1NQnzrUuxPm0T2Mki46T0jdwfUxENW-Q@mail.gmail.com>
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On Fri, 23 Jul 2021 12:41:46 -0400
Xin Long <lucien.xin@gmail.com> wrote:

> a fix already posted in tipc-discussion:
> 
> diff --git a/net/tipc/socket.c b/net/tipc/socket.c
> index 9b0b311c7ec1..b0dd183a4dbc 100644
> --- a/net/tipc/socket.c
> +++ b/net/tipc/socket.c
> @@ -1973,10 +1973,12 @@ static int tipc_recvmsg(struct socket *sock,
> struct msghdr *m,
>                 tipc_node_distr_xmit(sock_net(sk), &xmitq);
>         }
> 
> -       if (!skb_cb->bytes_read)
> -               tsk_advance_rx_queue(sk);
> +       if (skb_cb->bytes_read)
> +               goto exit;
> +
> +       tsk_advance_rx_queue(sk);
> 
> -       if (likely(!connected) || skb_cb->bytes_read)
> +       if (likely(!connected))
>                 goto exit;
> 

Ok, thank you for informing


With regards,
Pavel Skripkin