Linux Virtualization - Jun 2023 - [PATCH RFC net-next v4 4/8] vsock: make vsock bind reusable

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 at
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