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Commit bdfe273e authored by Clemens Ladisch's avatar Clemens Ladisch Committed by Stefan Richter
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firewire: cdev: fix race in iso context creation 



Protect the client's iso context pointer against a race that can happen
when more than one creation call is executed at the same time.

Signed-off-by: default avatarClemens Ladisch <clemens@ladisch.de>
Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
parent 33e553fe

drivers/firewire/core-cdev.c

+8 −5
Original line number Original line Diff line number Diff line
@@ -864,10 +864,6 @@ static int ioctl_create_iso_context(struct client *client, union ioctl_arg *arg) 
	struct fw_cdev_create_iso_context *a = &arg->create_iso_context;

	struct fw_cdev_create_iso_context *a = &arg->create_iso_context;

	struct fw_iso_context *context;

	struct fw_iso_context *context;





	/* We only support one context at this time. */

	if (client->iso_context != NULL)

		return -EBUSY;



	if (a->channel > 63)

	if (a->channel > 63)

		return -EINVAL;

		return -EINVAL;
@@ -892,10 +888,17 @@ static int ioctl_create_iso_context(struct client *client, union ioctl_arg *arg) 
	if (IS_ERR(context))

	if (IS_ERR(context))

		return PTR_ERR(context);

		return PTR_ERR(context);





	/* We only support one context at this time. */

	spin_lock_irq(&client->lock);

	if (client->iso_context != NULL) {

		spin_unlock_irq(&client->lock);

		fw_iso_context_destroy(context);

		return -EBUSY;

	}

	client->iso_closure = a->closure;

	client->iso_closure = a->closure;

	client->iso_context = context;

	client->iso_context = context;

	spin_unlock_irq(&client->lock);





	/* We only support one context at this time. */

	a->handle = 0;

	a->handle = 0;





	return 0;

	return 0;