From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Maciej Szmigiero , Andrew Lunn , "David S. Miller" Subject: [PATCH 4.2 012/124] net: fec: normalize return value of pm_runtime_get_sync() in MDIO write Date: Mon, 7 Dec 2015 09:55:02 -0500 Message-Id: <20151207144920.264767419@linuxfoundation.org> In-Reply-To: <20151207144919.656035367@linuxfoundation.org> References: <20151207144919.656035367@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Maciej S. Szmigiero" [ Upstream commit 42ea4457aea7aaeddf0c0b06724f297608f5e9d2 ] If fec MDIO write method succeeds its return value comes from call to pm_runtime_get_sync(). But pm_runtime_get_sync() can also return 1. In case of Micrel KSZ9031 PHY this value will then be returned along the call chain of phy_write() -> ksz9031_extended_write() -> ksz9031_center_flp_timing() -> ksz9031_config_init() -> phy_init_hw() -> phy_attach_direct() -> phy_connect_direct(). Then phy_connect() will cast it into a pointer using ERR_PTR(), which then fec_enet_mii_probe() will try to dereference resulting in an oops. Fix it by normalizing return value of pm_runtime_get_sync() to be zero if positive in MDIO write method. Fixes: 8fff755e9f8d ("net: fec: Ensure clocks are enabled while using mdio bus") Signed-off-by: Maciej Szmigiero Acked-by: Andrew Lunn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/freescale/fec_main.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -1811,11 +1811,13 @@ static int fec_enet_mdio_write(struct mi struct fec_enet_private *fep = bus->priv; struct device *dev = &fep->pdev->dev; unsigned long time_left; - int ret = 0; + int ret; ret = pm_runtime_get_sync(dev); if (ret < 0) return ret; + else + ret = 0; fep->mii_timeout = 0; reinit_completion(&fep->mdio_done);