net: korina: Fix NAPI versus resources freeing

commit e6afb1ad88feddf2347ea779cfaf4d03d3cd40b6 upstream.

Commit beb0babfb77e ("korina: disable napi on close and restart")
introduced calls to napi_disable() that were missing before,
unfortunately this leaves a small window during which NAPI has a chance
to run, yet we just freed resources since korina_free_ring() has been
called:

Fix this by disabling NAPI first then freeing resource, and make sure
that we also cancel the restart task before doing the resource freeing.

Fixes: beb0babfb77e ("korina: disable napi on close and restart")
Reported-by: Alexandros C. Couloumbis <alex@ozo.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/net/ethernet/korina.c b/drivers/net/ethernet/korina.c
index d8430f4..fcf65cc 100644 (file)
--- a/drivers/net/ethernet/korina.c
+++ b/drivers/net/ethernet/korina.c
@@ -906,10 +906,10 @@ static void korina_restart_task(struct work_struct *work)
                                DMA_STAT_DONE | DMA_STAT_HALT | DMA_STAT_ERR,
                                &lp->rx_dma_regs->dmasm);
 
-       korina_free_ring(dev);
-
        napi_disable(&lp->napi);
 
+       korina_free_ring(dev);
+
        if (korina_init(dev) < 0) {
                printk(KERN_ERR "%s: cannot restart device\n", dev->name);
                return;
@@ -1070,12 +1070,12 @@ static int korina_close(struct net_device *dev)
        tmp = tmp | DMA_STAT_DONE | DMA_STAT_HALT | DMA_STAT_ERR;
        writel(tmp, &lp->rx_dma_regs->dmasm);
 
-       korina_free_ring(dev);
-
        napi_disable(&lp->napi);
 
        cancel_work_sync(&lp->restart_task);
 
+       korina_free_ring(dev);
+
        free_irq(lp->rx_irq, dev);
        free_irq(lp->tx_irq, dev);
        free_irq(lp->ovr_irq, dev);