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Date:   Fri, 23 Jun 2023 10:15:23 +0200
From:   Stefano Garzarella <sgarzare@redhat.com>
To:     Bobby Eshleman <bobbyeshleman@gmail.com>
Cc:     Bobby Eshleman <bobby.eshleman@bytedance.com>,
        Stefan Hajnoczi <stefanha@redhat.com>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Jason Wang <jasowang@redhat.com>,
        Xuan Zhuo <xuanzhuo@linux.alibaba.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        "K. Y. Srinivasan" <kys@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
        Bryan Tan <bryantan@vmware.com>,
        Vishnu Dasa <vdasa@vmware.com>,
        VMware PV-Drivers Reviewers <pv-drivers@vmware.com>,
        Dan Carpenter <dan.carpenter@linaro.org>,
        Simon Horman <simon.horman@corigine.com>,
        Krasnov Arseniy <oxffffaa@gmail.com>, kvm@vger.kernel.org,
        virtualization@lists.linux-foundation.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org,
        bpf@vger.kernel.org
Subject: Re: [PATCH RFC net-next v4 4/8] vsock: make vsock bind reusable
Message-ID: <oq5c2c4snksklko6tmq44g73d6ihrbnqjyugsvfbhtdsnlrioi@hklfspvyjmad>
References: <20230413-b4-vsock-dgram-v4-0-0cebbb2ae899@bytedance.com>
 <20230413-b4-vsock-dgram-v4-4-0cebbb2ae899@bytedance.com>
 <p2tgn3wczd3t3dodyicczetr2nqnqpwcadz6ql5hpvg2cd2dxa@phheksxhxfna>
 <ZJTTx0XJ2LeITNh0@bullseye>
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On Thu, Jun 22, 2023 at 11:05:43PM +0000, Bobby Eshleman wrote:
>On Thu, Jun 22, 2023 at 05:25:55PM +0200, Stefano Garzarella wrote:
>> On Sat, Jun 10, 2023 at 12:58:31AM +0000, Bobby Eshleman wrote:
>> > This commit makes the bind table management functions in vsock usable
>> > for different bind tables. For use by datagrams in a future patch.
>> >
>> > Signed-off-by: Bobby Eshleman <bobby.eshleman@bytedance.com>
>> > ---
>> > net/vmw_vsock/af_vsock.c | 33 ++++++++++++++++++++++++++-------
>> > 1 file changed, 26 insertions(+), 7 deletions(-)
>> >
>> > diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
>> > index ef86765f3765..7a3ca4270446 100644
>> > --- a/net/vmw_vsock/af_vsock.c
>> > +++ b/net/vmw_vsock/af_vsock.c
>> > @@ -230,11 +230,12 @@ static void __vsock_remove_connected(struct vsock_sock *vsk)
>> > 	sock_put(&vsk->sk);
>> > }
>> >
>> > -static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
>> > +struct sock *vsock_find_bound_socket_common(struct sockaddr_vm *addr,
>> > +					    struct list_head *bind_table)
>> > {
>> > 	struct vsock_sock *vsk;
>> >
>> > -	list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table) {
>> > +	list_for_each_entry(vsk, bind_table, bound_table) {
>> > 		if (vsock_addr_equals_addr(addr, &vsk->local_addr))
>> > 			return sk_vsock(vsk);
>> >
>> > @@ -247,6 +248,11 @@ static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
>> > 	return NULL;
>> > }
>> >
>> > +static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
>> > +{
>> > +	return vsock_find_bound_socket_common(addr, vsock_bound_sockets(addr));
>> > +}
>> > +
>> > static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
>> > 						  struct sockaddr_vm *dst)
>> > {
>> > @@ -646,12 +652,17 @@ static void vsock_pending_work(struct work_struct *work)
>> >
>> > /**** SOCKET OPERATIONS ****/
>> >
>> > -static int __vsock_bind_connectible(struct vsock_sock *vsk,
>> > -				    struct sockaddr_vm *addr)
>> > +static int vsock_bind_common(struct vsock_sock *vsk,
>> > +			     struct sockaddr_vm *addr,
>> > +			     struct list_head *bind_table,
>> > +			     size_t table_size)
>> > {
>> > 	static u32 port;
>> > 	struct sockaddr_vm new_addr;
>> >
>> > +	if (table_size < VSOCK_HASH_SIZE)
>> > +		return -1;
>>
>> Why we need this check now?
>>
>
>If the table_size is not at least VSOCK_HASH_SIZE then the
>VSOCK_HASH(addr) used later could overflow the table.
>
>Maybe this really deserves a WARN() and a comment?

Yes, please WARN_ONCE() should be enough.

Stefano