netdev - [PATCH,RESEND] phylib: fix premature freeing of struct mii

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Message-ID: <20081118143307.GA12255@xi.wantstofly.org>
Date:	Tue, 18 Nov 2008 15:33:07 +0100
From:	Lennert Buytenhek <buytenh@...tstofly.org>
To:	jeff@...zik.org
Cc:	Bryan Wu <cooloney@...nel.org>, netdev@...r.kernel.org
Subject: [PATCH,RESEND] phylib: fix premature freeing of struct mii_bus

Commit 46abc02175b3c246dd5141d878f565a8725060c9 ("phylib: give mdio
buses a device tree presence") added a call to device_unregister() in
a situation where the caller did not intend for the device to be
freed yet, but apart from just unregistering the device from the
system, device_unregister() does an additional put_device() that is
intended to free it.

The right function to use in this situation is device_del(), which
unregisters the device from the system like device_unregister() does,
but without dropping the reference count an additional time.

Bug report from Bryan Wu <cooloney@...nel.org>.

Signed-off-by: Lennert Buytenhek <buytenh@...vell.com>
Tested-by: Bryan Wu <cooloney@...nel.org>

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 6671e2d..df06301 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -135,7 +135,7 @@ void mdiobus_unregister(struct mii_bus *bus)
 	BUG_ON(bus->state != MDIOBUS_REGISTERED);
 	bus->state = MDIOBUS_UNREGISTERED;

-	device_unregister(&bus->dev);
+	device_del(&bus->dev);
 	for (i = 0; i < PHY_MAX_ADDR; i++) {
 		if (bus->phy_map[i])
 			device_unregister(&bus->phy_map[i]->dev);
--
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