Commit 7c3f0d3d authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: seq: Check the conflicting port at port creation 



We didn't check if a port with the given port number has been already
present at creating a new port.  Check it and return -EBUSY properly
if the port number conflicts.

Reviewed-by: default avatarJaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-22-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 94c5b717

sound/core/seq/seq_clientmgr.c

+8 −4
Original line number Diff line number Diff line
@@ -1194,15 +1194,19 @@ static int snd_seq_ioctl_create_port(struct snd_seq_client *client, void *arg) 
	struct snd_seq_port_info *info = arg;

	struct snd_seq_client_port *port;

	struct snd_seq_port_callback *callback;

	int port_idx;

	int port_idx, err;



	/* it is not allowed to create the port for an another client */

	if (info->addr.client != client->number)

		return -EPERM;



	port = snd_seq_create_port(client, (info->flags & SNDRV_SEQ_PORT_FLG_GIVEN_PORT) ? info->addr.port : -1);

	if (port == NULL)

		return -ENOMEM;

	if (info->flags & SNDRV_SEQ_PORT_FLG_GIVEN_PORT)

		port_idx = info->addr.port;

	else

		port_idx = -1;

	err = snd_seq_create_port(client, port_idx, &port);

	if (err < 0)

		return err;



	if (client->type == USER_CLIENT && info->kernel) {

		port_idx = port->addr.port;

sound/core/seq/seq_ports.c

+16 −9
Original line number Diff line number Diff line
@@ -107,33 +107,34 @@ static void port_subs_info_init(struct snd_seq_port_subs_info *grp) 
}





/* create a port, port number is returned (-1 on failure);

/* create a port, port number or a negative error code is returned

 * the caller needs to unref the port via snd_seq_port_unlock() appropriately

 */

struct snd_seq_client_port *snd_seq_create_port(struct snd_seq_client *client,

						int port)

int snd_seq_create_port(struct snd_seq_client *client, int port,

			struct snd_seq_client_port **port_ret)

{

	struct snd_seq_client_port *new_port, *p;

	int num = -1;

	int num;

	

	*port_ret = NULL;



	/* sanity check */

	if (snd_BUG_ON(!client))

		return NULL;

		return -EINVAL;



	if (client->num_ports >= SNDRV_SEQ_MAX_PORTS) {

		pr_warn("ALSA: seq: too many ports for client %d\n", client->number);

		return NULL;

		return -EINVAL;

	}



	/* create a new port */

	new_port = kzalloc(sizeof(*new_port), GFP_KERNEL);

	if (!new_port)

		return NULL;	/* failure, out of memory */

		return -ENOMEM;	/* failure, out of memory */

	/* init port data */

	new_port->addr.client = client->number;

	new_port->addr.port = -1;

	new_port->owner = THIS_MODULE;

	sprintf(new_port->name, "port-%d", num);

	snd_use_lock_init(&new_port->use_lock);

	port_subs_info_init(&new_port->c_src);

	port_subs_info_init(&new_port->c_dest);
@@ -143,6 +144,10 @@ struct snd_seq_client_port *snd_seq_create_port(struct snd_seq_client *client, 
	mutex_lock(&client->ports_mutex);

	write_lock_irq(&client->ports_lock);

	list_for_each_entry(p, &client->ports_list_head, list) {

		if (p->addr.port == port) {

			num = -EBUSY;

			goto unlock;

		}

		if (p->addr.port > num)

			break;

		if (port < 0) /* auto-probe mode */
@@ -153,10 +158,12 @@ struct snd_seq_client_port *snd_seq_create_port(struct snd_seq_client *client, 
	client->num_ports++;

	new_port->addr.port = num;	/* store the port number in the port */

	sprintf(new_port->name, "port-%d", num);

	*port_ret = new_port;

 unlock:

	write_unlock_irq(&client->ports_lock);

	mutex_unlock(&client->ports_mutex);



	return new_port;

	return num;

}



/* */

sound/core/seq/seq_ports.h

+3 −2
Original line number Diff line number Diff line
@@ -86,8 +86,9 @@ struct snd_seq_client_port *snd_seq_port_query_nearest(struct snd_seq_client *cl 
/* unlock the port */

#define snd_seq_port_unlock(port) snd_use_lock_free(&(port)->use_lock)



/* create a port, port number is returned (-1 on failure) */

struct snd_seq_client_port *snd_seq_create_port(struct snd_seq_client *client, int port_index);

/* create a port, port number or a negative error code is returned */

int snd_seq_create_port(struct snd_seq_client *client, int port_index,

			struct snd_seq_client_port **port_ret);



/* delete a port */

int snd_seq_delete_port(struct snd_seq_client *client, int port);