From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3412A34197 for ; Mon, 16 Oct 2023 18:33:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="SKs2otoj" Received: from out-192.mta0.migadu.com (out-192.mta0.migadu.com [91.218.175.192]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 743B3AC for ; Mon, 16 Oct 2023 11:33:45 -0700 (PDT) Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1697481223; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BmI76kh43dBmjzgMNopprOw8nRKDf8jqaWGHiQ+q6Pc=; b=SKs2otojdfa1Ss5Yhvc8WJYUoarN3sKus91YK8c4ny08xjgS8F89ElxpdtYds4AEzp95ci Li59hsdFNkJNszJF7SIuejM/uiciLIaU+atRxUOIkGfJtTHXgqWpUL2S8JHC5f77Vi7crU vLrvhUpZ4ga+rulYv61kh42EBP36Q4Y= Date: Mon, 16 Oct 2023 11:33:36 -0700 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next v2] Only run BPF cgroup unix sockaddr recvmsg() hooks on named sockets Content-Language: en-US To: Kuniyuki Iwashima , daan.j.demeyer@gmail.com Cc: bpf@vger.kernel.org, kernel-team@meta.com, netdev@vger.kernel.org References: <20231012085216.219918-1-daan.j.demeyer@gmail.com> <20231012181142.60636-1-kuniyu@amazon.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Martin KaFai Lau In-Reply-To: <20231012181142.60636-1-kuniyu@amazon.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED, SPF_HELO_NONE,SPF_PASS,T_FILL_THIS_FORM_SHORT autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On 10/12/23 11:11 AM, Kuniyuki Iwashima wrote: > From: Daan De Meyer > Date: Thu, 12 Oct 2023 10:52:13 +0200 >> Changes since v1: >> >> * Added missing Signed-off-by tag > > You can put these after --- so that it will disappear when merged. > > >> >> We should not run the recvmsg() hooks on unnamed sockets as we do >> not run them on unnamed sockets in the other hooks either. We may >> look into relaxing this later but for now let's make sure we are >> consistent and not run the hooks on unnamed sockets anywhere. >> >> Signed-off-by: Daan De Meyer >> --- >> net/unix/af_unix.c | 14 ++++++++------ >> 1 file changed, 8 insertions(+), 6 deletions(-) >> >> diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c >> index e10d07c76044..81fb8bddaff9 100644 >> --- a/net/unix/af_unix.c >> +++ b/net/unix/af_unix.c >> @@ -2416,9 +2416,10 @@ int __unix_dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t size, >> if (msg->msg_name) { >> unix_copy_addr(msg, skb->sk); > > How is an unnamed socket set to skb->sk ? I had a similar question. Most likely socketpair? Please add an explanation in the commit message in v3. Please also help to add a selftest for this case. > > >> >> - BPF_CGROUP_RUN_PROG_UNIX_RECVMSG_LOCK(sk, >> - msg->msg_name, >> - &msg->msg_namelen); >> + if (msg->msg_namelen > 0) >> + BPF_CGROUP_RUN_PROG_UNIX_RECVMSG_LOCK(sk, >> + msg->msg_name, >> + &msg->msg_namelen); >> } >> >> if (size > skb->len - skip) >> @@ -2773,9 +2774,10 @@ static int unix_stream_read_generic(struct unix_stream_read_state *state, >> state->msg->msg_name); >> unix_copy_addr(state->msg, skb->sk); >> >> - BPF_CGROUP_RUN_PROG_UNIX_RECVMSG_LOCK(sk, >> - state->msg->msg_name, >> - &state->msg->msg_namelen); >> + if (state->msg->msg_namelen > 0) >> + BPF_CGROUP_RUN_PROG_UNIX_RECVMSG_LOCK(sk, >> + state->msg->msg_name, >> + &state->msg->msg_namelen); >> >> sunaddr = NULL; >> } >> -- >> 2.41.0 >>