hostap: Protect against initialization interrupt

Use an irq spinlock to hold off the IRQ handler until
enough early card init is complete such that the handler
can run without faulting.

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Cc: stable@kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/net/wireless/hostap/hostap_hw.c b/drivers/net/wireless/hostap/hostap_hw.c
index ff9b5c882184..2f999fc94f60 100644
--- a/drivers/net/wireless/hostap/hostap_hw.c
+++ b/drivers/net/wireless/hostap/hostap_hw.c
@@ -2621,6 +2621,18 @@ static irqreturn_t prism2_interrupt(int irq, void *dev_id)
         iface = netdev_priv(dev);
         local = iface->local;
 
+        /* Detect early interrupt before driver is fully configued */
+        spin_lock(&local->irq_init_lock);
+        if (!dev->base_addr) {
+                if (net_ratelimit()) {
+                        printk(KERN_DEBUG "%s: Interrupt, but dev not configured\n",
+                               dev->name);
+                }
+                spin_unlock(&local->irq_init_lock);
+                return IRQ_HANDLED;
+        }
+        spin_unlock(&local->irq_init_lock);
+
         prism2_io_debug_add(dev, PRISM2_IO_DEBUG_CMD_INTERRUPT, 0, 0);
 
         if (local->func->card_present && !local->func->card_present(local)) {
@@ -3138,6 +3150,7 @@ prism2_init_local_data(struct prism2_helper_functions *funcs, int card_idx,
         spin_lock_init(&local->cmdlock);
         spin_lock_init(&local->baplock);
         spin_lock_init(&local->lock);
+        spin_lock_init(&local->irq_init_lock);
         mutex_init(&local->rid_bap_mtx);
 
         if (card_idx < 0 || card_idx >= MAX_PARM_DEVICES)