Commit c91bc6cc authored Jul 23, 2013 by Xiaotian Feng Committed by Tejun Heo Jul 23, 2013

ahci: fix Null pointer dereference in achi_host_active()



commit b29900e6 (AHCI: Make distinct names for ports in /proc/interrupts)
introuded a regression, which resulted Null pointer dereference for achi
host with dummy ports. For ahci ports, when the port is dummy port, its
private_data will be NULL, as ata_dummy_port_ops doesn't support ->port_start.

changes in v2: use pp to check dummy ports, update comments

Reported-and-tested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Xiaotian Feng <xtfeng@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alexander Gordeev <agordeev@redhat.com>
Cc: linux-ide@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

parent bb969619

drivers/ata/ahci.c

+8 −1

Original line number	Diff line number	Diff line
		@@ -1146,11 +1146,18 @@ int ahci_host_activate(struct ata_host *host, int irq, unsigned int n_msis)
		return rc;

		for (i = 0; i < host->n_ports; i++) {
		const char* desc;
		struct ahci_port_priv *pp = host->ports[i]->private_data;

		/* pp is NULL for dummy ports */
		if (pp)
		desc = pp->irq_desc;
		else
		desc = dev_driver_string(host->dev);

		rc = devm_request_threaded_irq(host->dev,
		irq + i, ahci_hw_interrupt, ahci_thread_fn, IRQF_SHARED,
		pp->irq_desc, host->ports[i]);
		desc, host->ports[i]);
		if (rc)
		goto out_free_irqs;
		}