From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 79F0E318B9E; Tue, 3 Feb 2026 16:37:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770136673; cv=none; b=Pju/P+eBm4xzzAt+PKPJ83SbuzuNqFCB7WbyokmQAyctKCxixOLiAHHtrq8mUPumGCZEMno8LRcP1fSRG0EdhapX9EEl/gjkpUjP+K3N7zB2l1021OcuRuzMbhtvIqv9QhxI6yp7W3i6si/GiW9I5NDTQ9IP0wZkO9do176C1h8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770136673; c=relaxed/simple; bh=rOKpqdPFYggKJpVAU6wtXwf20Rvom0J8VquNYFXXENc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=UOBG3MQZ0c/SbHJaY0MXoIhw7GKR+XxK1mGYRdh9de5ez3++VMTI9xzzyVMxIcWZXXTD1P0LQFWF+s8Ryz9G4WdOmg+AUhVdjkv/mKW46x2q8gwtG+wTziia05pAZOABLB4oDQYayCJ8wwGPqIEsCTVmCs5PmFAn97rEptLOSy0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=z2KUZZOx; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="z2KUZZOx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B318BC116D0; Tue, 3 Feb 2026 16:37:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1770136673; bh=rOKpqdPFYggKJpVAU6wtXwf20Rvom0J8VquNYFXXENc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=z2KUZZOxKyL/VB8C8JZj8E68RxyNC/hSBr1iHg1KFY2Sd4Zb4YBO8PUAnLkSHPCiJ 7YEW7kTfPZUS5cWkGi1fjm+oZAxOnfUlVy7h4CCetXoYJxzC7F9rxFp6Ioy75omyvI BcnSBDUkUzakPDT689X4Jw6dpeYXuF8DZfZ9CS3w= Date: Tue, 3 Feb 2026 17:37:50 +0100 From: Greg Kroah-Hartman To: David =?iso-8859-1?Q?Nystr=F6m?= Cc: stable@vger.kernel.org, Sasha Levin , netdev@vger.kernel.org, Zeng Heng , Paolo Abeni , Yang Yingliang , "Russell King (Oracle)" Subject: Re: [PATCH 5.10] net: mdio: fix unbalanced fwnode reference count in mdio_device_release() Message-ID: <2026020318-affected-irritate-cda7@gregkh> References: <20260116-backport_cb37617687f2_20260115100804-v1-1-9796615d93ab@est.tech> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260116-backport_cb37617687f2_20260115100804-v1-1-9796615d93ab@est.tech> On Fri, Jan 16, 2026 at 11:14:45AM +0100, David Nyström wrote: > [ Upstream commit cb37617687f2bfa5b675df7779f869147c9002bd ] > > There is warning report about of_node refcount leak > while probing mdio device: > > OF: ERROR: memory leak, expected refcount 1 instead of 2, > of_node_get()/of_node_put() unbalanced - destroy cset entry: > attach overlay node /spi/soc@0/mdio@710700c0/ethernet@4 > > In of_mdiobus_register_device(), we increase fwnode refcount > by fwnode_handle_get() before associating the of_node with > mdio device, but it has never been decreased in normal path. > Since that, in mdio_device_release(), it needs to call > fwnode_handle_put() in addition instead of calling kfree() > directly. > > After above, just calling mdio_device_free() in the error handle > path of of_mdiobus_register_device() is enough to keep the > refcount balanced. > > (cherry picked from commit cb37617687f2bfa5b675df7779f869147c9002bd) > > Fixes: a9049e0c513c ("mdio: Add support for mdio drivers.") > Signed-off-by: Zeng Heng > Reviewed-by: Yang Yingliang > Reviewed-by: Russell King (Oracle) > Link: https://lore.kernel.org/r/20221203073441.3885317-1-zengheng4@huawei.com > Signed-off-by: Paolo Abeni > Signed-off-by: David Nyström > --- > This series backports 1 commit(s) to the 5.10 stable tree. > --- > drivers/net/mdio/of_mdio.c | 3 ++- > drivers/net/phy/mdio_device.c | 2 ++ > 2 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/mdio/of_mdio.c b/drivers/net/mdio/of_mdio.c > index b254127cea50..355c3ee21cd7 100644 > --- a/drivers/net/mdio/of_mdio.c > +++ b/drivers/net/mdio/of_mdio.c > @@ -168,8 +168,9 @@ static int of_mdiobus_register_device(struct mii_bus *mdio, > /* All data is now stored in the mdiodev struct; register it. */ > rc = mdio_device_register(mdiodev); > if (rc) { > + device_set_node(&mdiodev->dev, NULL); > + fwnode_handle_put(fwnode); > mdio_device_free(mdiodev); > - of_node_put(child); > return rc; > } > > diff --git a/drivers/net/phy/mdio_device.c b/drivers/net/phy/mdio_device.c > index 797c41f5590e..f72d18ee2792 100644 > --- a/drivers/net/phy/mdio_device.c > +++ b/drivers/net/phy/mdio_device.c > @@ -21,6 +21,7 @@ > #include > #include > #include > +#include > > void mdio_device_free(struct mdio_device *mdiodev) > { > @@ -30,6 +31,7 @@ EXPORT_SYMBOL(mdio_device_free); > > static void mdio_device_release(struct device *dev) > { > + fwnode_handle_put(dev->fwnode); > kfree(to_mdio_device(dev)); > } > > > --- > base-commit: f964b940099f9982d723d4c77988d4b0dda9c165 > change-id: 20260115-backport_cb37617687f2_20260115100804-bb6cefe39d44 > > Best regards, > -- > David Nyström > Breaks the build, how did you test this: drivers/net/mdio/of_mdio.c: In function ‘of_mdiobus_register_device’: drivers/net/mdio/of_mdio.c:172:35: error: ‘fwnode’ undeclared (first use in this function); did you mean ‘inode’? 172 | fwnode_handle_put(fwnode); | ^~~~~~ | inode