From c91bc6ccd13254826fdfceddba0f3b5e308aa93e Mon Sep 17 00:00:00 2001 From: Xiaotian Feng Date: Tue, 23 Jul 2013 11:54:10 +0800 Subject: [PATCH] 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 Signed-off-by: Xiaotian Feng Signed-off-by: Tejun Heo Cc: Alexander Gordeev Cc: linux-ide@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- drivers/ata/ahci.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c index 5064f3e..db4380d 100644 --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -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; } -- 2.7.4