From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 C6EC6282F17; Thu, 28 May 2026 20:19:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779999572; cv=none; b=uYlF3MfCDN3NFzjoJoaWw575LyPmcwAu0uLedkgFRjgq8MvjW+4oUHhC+ct4Bwgi/slhbLTizjq53EaKbKISDskIcwsp9ofI8Ks6A189wP0sGHLuMAsckr4VptOles5xiXZUHTWpOCrQeMHyjtaCNjbPAm/c3EN33r8oRl3uj+A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779999572; c=relaxed/simple; bh=NN0GtpwL5zbwn9ouzInVHmVIrFTlqcL60KwyA3oRawY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SZrPzD7XbRNvg3bTRdjxW3NLExOt3L5hMnfGqW+OZm1p2WwCHv3UXeedH8bjMB1gXSXB9UPQ5PDoNWbFl9bUL5NzE9RMNf9eYUCNM1X5HCx1psmx9MFOAq2voJ3RlssC0W7S7ijVmJ+3JSDoVxupBeYIzOQCweZfXHBvYRl9nZU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=w4sDPaA+; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="w4sDPaA+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 319731F000E9; Thu, 28 May 2026 20:19:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779999571; bh=qQNB1fSGVEE33DCPK54UL+YzwViqhM1rMCTV5Bwroz8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=w4sDPaA+PLGRZgCcBHw6T/j/TfVRvebEP+ZS87su57lh6+oEfaKAs/uDs30PdZrWg Oh1TNbc1jeBVLT1/7JmFCPwpzVGeTl5XAMzhp/+YjkbWgTBYJtqcLf6HnlqwvAiMqW YNmRBIYvFQCkdeb4u6nhVcEQaJenF7K8D5OYrOX4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, David Carlier , Maxime Chevallier , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.18 077/377] net: ethtool: phy: avoid NULL deref when PHY driver is unbound Date: Thu, 28 May 2026 21:45:15 +0200 Message-ID: <20260528194640.602747042@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260528194638.371537336@linuxfoundation.org> References: <20260528194638.371537336@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Carlier [ Upstream commit e3adf69f8eb121a9128c2b0029efd050d3649153 ] phydev->drv can become NULL while the phy_device is still attached to its net_device, namely after the PHY driver is unbound via sysfs: echo > /sys/bus/mdio_bus/drivers//unbind phy_remove() clears phydev->drv but doesn't call phy_detach(), so the phy_device stays in the link topology xarray and ethnl_req_get_phydev() still hands it back. ETHTOOL_MSG_PHY_GET then oopses on: rep_data->drvname = kstrdup(phydev->drv->name, GFP_KERNEL); drvname is already treated as optional by phy_reply_size(), phy_fill_reply() and phy_cleanup_data(), so just skip the allocation when there is no driver bound. Fixes: 9dd2ad5e92b9 ("net: ethtool: phy: Convert the PHY_GET command to generic phy dump") Cc: stable@vger.kernel.org # 6.13.x Signed-off-by: David Carlier Reviewed-by: Maxime Chevallier Tested-by: Maxime Chevallier Link: https://patch.msgid.link/20260509215046.107157-1-devnexen@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/ethtool/phy.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/net/ethtool/phy.c +++ b/net/ethtool/phy.c @@ -94,10 +94,12 @@ static int phy_prepare_data(const struct if (!rep_data->name) return -ENOMEM; - rep_data->drvname = kstrdup(phydev->drv->name, GFP_KERNEL); - if (!rep_data->drvname) { - ret = -ENOMEM; - goto err_free_name; + if (phydev->drv) { + rep_data->drvname = kstrdup(phydev->drv->name, GFP_KERNEL); + if (!rep_data->drvname) { + ret = -ENOMEM; + goto err_free_name; + } } rep_data->upstream_type = pdn->upstream_type;