Re: [PATCH 1/2] iscsi_tcp: do not bind sockets that already have extra callbacks

[Mike Christie]

On 3/18/24 2:49 PM, Khazhismel Kumykov wrote:
> This attempts to avoid a situation where a misbehaving iscsi daemon
> passes a socket for a different iSCSI connection to BIND_CONN - which
> would result in infinite recursion and stack overflow. This will
> also prevent passing *other* sockets which had sk_user_data overridden,
> but that wouldn't have been safe anyways - since we throw away that
> pointer anyways. This does not cover all hypothetical scenarios where we
> pass bad sockets to BIND_CONN.
> 
> This also papers over a different bug - we allow a daemon to call
> BIND_CONN twice for the same connection - which would result in, at the
> least, failing to uninitialize/teardown the previous socket, which will
> be addressed separately.
> 
> Signed-off-by: Khazhismel Kumykov <khazhy@xxxxxxxxxx>
> ---
>  drivers/scsi/iscsi_tcp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
> index 8e14cea15f98..e8ed60b777c6 100644
> --- a/drivers/scsi/iscsi_tcp.c
> +++ b/drivers/scsi/iscsi_tcp.c
> @@ -725,7 +725,7 @@ iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
>  	}
>  
>  	err = -EINVAL;
> -	if (!sk_is_tcp(sock->sk))
> +	if (!sk_is_tcp(sock->sk) || sock->sk->sk_user_data)
>  		goto free_socket;
>  
>  	err = iscsi_conn_bind(cls_session, cls_conn, is_leading);


Reviewed-by: Mike Christie <michael.christie@xxxxxxxxxx>