[PATCH] net: macb: fix ref count leaking via pm_runtime_get_sync

[Navid Emamdoost]

in macb_mdio_write, macb_mdio_read, and at91ether_open,
pm_runtime_get_sync is called which increments the counter even in case of
failure, leading to incorrect ref count.
In case of failure, decrement the ref count before returning.

Signed-off-by: Navid Emamdoost <navid.emamdo...@gmail.com>
---
 drivers/net/ethernet/cadence/macb_main.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c 
b/drivers/net/ethernet/cadence/macb_main.c
index a0e8c5bbabc0..3646ab5a1e83 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -335,7 +335,7 @@ static int macb_mdio_read(struct mii_bus *bus, int mii_id, 
int regnum)
 
        status = pm_runtime_get_sync(&bp->pdev->dev);
        if (status < 0)
-               goto mdio_pm_exit;
+               goto mdio_pm_put;
 
        status = macb_mdio_wait_for_idle(bp);
        if (status < 0)
@@ -374,6 +374,7 @@ static int macb_mdio_read(struct mii_bus *bus, int mii_id, 
int regnum)
 
 mdio_read_exit:
        pm_runtime_mark_last_busy(&bp->pdev->dev);
+mdio_pm_put:
        pm_runtime_put_autosuspend(&bp->pdev->dev);
 mdio_pm_exit:
        return status;
@@ -387,7 +388,7 @@ static int macb_mdio_write(struct mii_bus *bus, int mii_id, 
int regnum,
 
        status = pm_runtime_get_sync(&bp->pdev->dev);
        if (status < 0)
-               goto mdio_pm_exit;
+               goto mdio_pm_put;
 
        status = macb_mdio_wait_for_idle(bp);
        if (status < 0)
@@ -426,6 +427,7 @@ static int macb_mdio_write(struct mii_bus *bus, int mii_id, 
int regnum,
 
 mdio_write_exit:
        pm_runtime_mark_last_busy(&bp->pdev->dev);
+mdio_pm_put:
        pm_runtime_put_autosuspend(&bp->pdev->dev);
 mdio_pm_exit:
        return status;
@@ -3817,7 +3819,7 @@ static int at91ether_open(struct net_device *dev)
 
        ret = pm_runtime_get_sync(&lp->pdev->dev);
        if (ret < 0)
-               return ret;
+               goto out;
 
        /* Clear internal statistics */
        ctl = macb_readl(lp, NCR);
@@ -3827,7 +3829,7 @@ static int at91ether_open(struct net_device *dev)
 
        ret = at91ether_start(dev);
        if (ret)
-               return ret;
+               goto out;
 
        /* Enable MAC interrupts */
        macb_writel(lp, IER, MACB_BIT(RCOMP)    |
@@ -3840,11 +3842,14 @@ static int at91ether_open(struct net_device *dev)
 
        ret = macb_phylink_connect(lp);
        if (ret)
-               return ret;
+               goto out;
 
        netif_start_queue(dev);
 
        return 0;
+out:
+       pm_runtime_put(&lp->pdev->dev);
+       return ret;
 }
 
 /* Close the interface */
-- 
2.17.1