From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 101D7C43334 for ; Sat, 9 Jul 2022 03:06:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229508AbiGIDGL (ORCPT ); Fri, 8 Jul 2022 23:06:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43402 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229379AbiGIDGH (ORCPT ); Fri, 8 Jul 2022 23:06:07 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2CE077B791; Fri, 8 Jul 2022 20:06:07 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id BCB6BB82A35; Sat, 9 Jul 2022 03:06:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9D39EC341C0; Sat, 9 Jul 2022 03:06:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1657335964; bh=U1K6nef6J4x5j2XZwh1q8ZuqeJJFO88Lt/OQry2fCKw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=RC3lVRzP8QHAXO23r0o/AgJAlXIPlF75VO9wbzqXPFl0327gY9yesP6+YxwL+rKH7 Rn+U+mCqgj6lq0AST5RPzgzIEVOXJ5Tmbghas1cnC9jRHj8cq/L/8/2Vw1akeYYPXi YVZdONr1SOKWKW6HXF16WCx/FUpllbuefJ8amYI/mjTb2aVokXg20+MF4tKFiZsUA6 rksCcjmuIbgI2WhmTC9pmxqbdD38c+s1ui9h73vJgqM3IH/3/sErpWvi4Y1xVN1Wrl 3XW8GqvdFH+eg6tBLruRl8Id1JAFqItTKC0QntSVnDRuxazNHbZiWBRgVaVAnRODZC iUoyEclRJLfGg== Date: Fri, 8 Jul 2022 20:06:02 -0700 From: Jakub Kicinski To: Hawkins Jiawei Cc: syzbot+5f26f85569bd179c18ce@syzkaller.appspotmail.com, andrii@kernel.org, ast@kernel.org, borisp@nvidia.com, bpf@vger.kernel.org, daniel@iogearbox.net, davem@davemloft.net, edumazet@google.com, guwen@linux.alibaba.com, yoshfuji@linux-ipv6.org, dsahern@kernel.org, john.fastabend@gmail.com, kafai@fb.com, kgraul@linux.ibm.com, kpsingh@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, songliubraving@fb.com, syzkaller-bugs@googlegroups.com, yhs@fb.com, skhan@linuxfoundation.org, 18801353760@163.com, paskripkin@gmail.com, linux-kernel-mentees@lists.linuxfoundation.org Subject: Re: [PATCH] smc: fix refcount bug in sk_psock_get (2) Message-ID: <20220708200602.1059bc09@kernel.org> In-Reply-To: <20220709024659.6671-1-yin31149@gmail.com> References: <00000000000026328205e08cdbeb@google.com> <20220709024659.6671-1-yin31149@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 9 Jul 2022 10:46:59 +0800 Hawkins Jiawei wrote: > Reported-and-tested-by: syzbot+5f26f85569bd179c18ce@syzkaller.appspotmail.com > Signed-off-by: hawk <18801353760@163.com> > --- > net/ipv4/tcp.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c > index 9984d23a7f3e..a1e6cab2c748 100644 > --- a/net/ipv4/tcp.c > +++ b/net/ipv4/tcp.c > @@ -3395,10 +3395,23 @@ static int do_tcp_setsockopt(struct sock *sk, int level, int optname, > } > case TCP_ULP: { > char name[TCP_ULP_NAME_MAX]; > + struct sock *smc_sock; > > if (optlen < 1) > return -EINVAL; > > + /* SMC sk_user_data may be treated as psock, > + * which triggers a refcnt warning. > + */ > + rcu_read_lock(); > + smc_sock = rcu_dereference_sk_user_data(sk); > + if (level == SOL_TCP && smc_sock && > + smc_sock->__sk_common.skc_family == AF_SMC) { This should prolly be under the socket lock? Can we add a bit to SK_USER_DATA_PTRMASK and have ULP-compatible users (sockmap) opt into ULP cooperation? Modifying TCP is backwards, layer-wise. > + rcu_read_unlock(); > + return -EOPNOTSUPP; > + } > + rcu_read_unlock(); > +