From patchwork Sun Nov 26 14:10:45 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Claudiu X-Patchwork-Id: 13468853 X-Patchwork-Delegate: kuba@kernel.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=tuxon.dev header.i=@tuxon.dev header.b="CFYFTrSx" Received: from mail-ej1-x634.google.com (mail-ej1-x634.google.com [IPv6:2a00:1450:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 370B5EB for ; Sun, 26 Nov 2023 06:10:53 -0800 (PST) Received: by mail-ej1-x634.google.com with SMTP id a640c23a62f3a-a00a9c6f283so453252566b.0 for ; Sun, 26 Nov 2023 06:10:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tuxon.dev; s=google; t=1701007851; x=1701612651; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=Vf3BBbGgK38KEJry5f+skZG4ReehlnPep5PbY6SoWGQ=; b=CFYFTrSxcrA8TfeWR3G1Y5sOoDm20rR8R3NFf7ESSCc1n4ILNyrT7g0Y6sTs38NX3S jUW8ttrPG+5UZ4PbQKYpoESwyo5BSFnVjZSMrCiS3iD6nd/Ys41qcLD2deUV0fVNz/9X wGjcLv2FrQiB9qz7albIHwfi51Rr/dBofveH27wAjBhFmi4iCzkuTSjgBDl+zc4FTJT3 9f/PiDwuLdQxMKvLL9r2djR9lY5Ad8cucSlmk8SZwQSSKSfiUvHc56mnOKp/LbRsLWqJ 1nDqoLj1CNesd3K+MAl3vzxIoVh53/xip0H+gwRNY4x+0v8esbFbCKYBPM5aa9O/0TnP w2Sg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701007851; x=1701612651; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Vf3BBbGgK38KEJry5f+skZG4ReehlnPep5PbY6SoWGQ=; b=a8f0LgNpEwjKST8VACxAn/jxPpdmPjGT90eQMXpqeEXyNdwFBwmCL+4uT1tcy6tvCo pAVQKcURFQQHMkzigJ15T+eugHq+usrecDIJEY9s8Nq5pOHJgXeHbDdJ2ABsHkg3+DiI TjZ15CfZ6AV/rzE1kLc2VmNxkNjDj5OQM/6tHxsupSTxa89J5f6fhu+4QCJPhZKM7nLD 4v0HX8xXrCVV+0zmKN+K1QBvvc/1kFLekOndWqWGfGyutFg5KmQqvLt8Sn5lXmx+TpUK eFNsPcLWHFFsKc3DEaIHcr2mbi+bfD8QmoZCMmQy1zxNXL0ne2Z6+E1MTCjEjvaixUMJ AGaw== X-Gm-Message-State: AOJu0YxTokOuFjWsL2ubiwh8h5Np5v426KQzXB975eN+Aqjo28iQMhHb J6NLLm0Verz7t6rzgs0oYdJvdg== X-Google-Smtp-Source: AGHT+IFQxU7KH05yMJU+q5DjIE3FNct1n5ReGHCv7CyKkjdrnTGipQuhi7GpiH5b23rMBzVDJj8YEQ== X-Received: by 2002:a17:906:4e:b0:a0d:a567:b92a with SMTP id 14-20020a170906004e00b00a0da567b92amr1525873ejg.39.1701007851676; Sun, 26 Nov 2023 06:10:51 -0800 (PST) Received: from claudiu-X670E-Pro-RS.. ([82.78.167.125]) by smtp.gmail.com with ESMTPSA id mb22-20020a170906eb1600b009fc0c42098csm4603423ejb.173.2023.11.26.06.10.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 26 Nov 2023 06:10:51 -0800 (PST) From: Claudiu Beznea To: nicolas.ferre@microchip.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, andrew@lunn.ch, hkallweit1@gmail.com, linux@armlinux.org.uk, jgarzik@pobox.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Claudiu Beznea Subject: [PATCH 1/2] net: phy: Check phydev->drv before dereferencing it Date: Sun, 26 Nov 2023 16:10:45 +0200 Message-Id: <20231126141046.3505343-2-claudiu.beznea@tuxon.dev> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231126141046.3505343-1-claudiu.beznea@tuxon.dev> References: <20231126141046.3505343-1-claudiu.beznea@tuxon.dev> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org The macb driver calls mdiobus_unregister() and mdiobus_free() in its remove function before calling unregister_netdev(). unregister_netdev() calls the driver-specific struct net_device_ops::ndo_stop function (macb_close()), and macb_close() calls phylink_disconnect_phy(). This, in turn, will call: phy_disconnect() -> phy_free_interrupt() -> phy_disable_interrupts() -> phy_config_interrupt() which dereference phydev->drv, which was already freed by: mdiobus_unregister() -> phy_mdio_device_remove() -> device_del() -> bus_remove_device() -> device_release_driver_internal() -> phy_remove() from macb_close(). Although the sequence in the macb driver is not correct, check phydev->drv       before dereferencing it in phy_config_interrupt() to avoid scenarios like the one described. Fixes: 00db8189d984 ("This patch adds a PHY Abstraction Layer to the Linux Kernel") Signed-off-by: Claudiu Beznea --- drivers/net/phy/phy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index a5fa077650e8..dd98a4b3ef81 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -165,7 +165,7 @@ EXPORT_SYMBOL_GPL(phy_get_rate_matching); static int phy_config_interrupt(struct phy_device *phydev, bool interrupts) { phydev->interrupts = interrupts ? 1 : 0; - if (phydev->drv->config_intr) + if (phydev->drv && phydev->drv->config_intr) return phydev->drv->config_intr(phydev); return 0;