[for-4.4,04/16] net: korina: Fix NAPI versus resources freeing

Message ID 1498801600-20896-5-git-send-email-amit.pundir@linaro.org
State New
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Series
  • Stable commits picked up from lede project
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Commit Message

Amit Pundir June 30, 2017, 5:46 a.m.
From: Florian Fainelli <f.fainelli@gmail.com>


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: Amit Pundir <amit.pundir@linaro.org>

---
To be cherry-picked on linux-3.18.y and linux-4.9.y as well.

 drivers/net/ethernet/korina.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

-- 
2.7.4

Patch

diff --git a/drivers/net/ethernet/korina.c b/drivers/net/ethernet/korina.c
index d74f5f4e5782..07eabf72c480 100644
--- a/drivers/net/ethernet/korina.c
+++ b/drivers/net/ethernet/korina.c
@@ -900,10 +900,10 @@  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;
@@ -1064,12 +1064,12 @@  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);