Re: [PATCH RFC net-next v4 4/8] vsock: make vsock bind reusable

[Stefano Garzarella]

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@xxxxxxxxxxxxx>
> > > ---
> > > 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