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 8198511710 for ; Mon, 11 Sep 2023 15:28:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 021F3C433C9; Mon, 11 Sep 2023 15:28:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694446098; bh=g+r2QTXP1nMVJInCJQ8FGsrjY+0EVISl8wLyscPgbRk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2E//iZEEFqsJFE/fFTV731jfgEnia1wJmEgSe2ZLkmxS2CN0ZbVX4Ffh8eLxKnkfm BfAUXc1kiIObKY6g1Gh1n5FhOmAKSYj2VGzqV0JEaT5XLwbWfU0GgXbgK8m0FOtnS4 qVvAGxywx90bQeie0CB3/VsPpvXU9E/Ww2xU/8og= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, RD Babiera , Heikki Krogerus , Guenter Roeck Subject: [PATCH 6.1 582/600] usb: typec: bus: verify partner exists in typec_altmode_attention Date: Mon, 11 Sep 2023 15:50:15 +0200 Message-ID: <20230911134650.802140057@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230911134633.619970489@linuxfoundation.org> References: <20230911134633.619970489@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: RD Babiera commit f23643306430f86e2f413ee2b986e0773e79da31 upstream. Some usb hubs will negotiate DisplayPort Alt mode with the device but will then negotiate a data role swap after entering the alt mode. The data role swap causes the device to unregister all alt modes, however the usb hub will still send Attention messages even after failing to reregister the Alt Mode. type_altmode_attention currently does not verify whether or not a device's altmode partner exists, which results in a NULL pointer error when dereferencing the typec_altmode and typec_altmode_ops belonging to the altmode partner. Verify the presence of a device's altmode partner before sending the Attention message to the Alt Mode driver. Fixes: 8a37d87d72f0 ("usb: typec: Bus type for alternate modes") Cc: stable@vger.kernel.org Signed-off-by: RD Babiera Reviewed-by: Heikki Krogerus Reviewed-by: Guenter Roeck Link: https://lore.kernel.org/r/20230814180559.923475-1-rdbabiera@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/typec/bus.c | 12 ++++++++++-- drivers/usb/typec/tcpm/tcpm.c | 3 ++- include/linux/usb/typec_altmode.h | 2 +- 3 files changed, 13 insertions(+), 4 deletions(-) --- a/drivers/usb/typec/bus.c +++ b/drivers/usb/typec/bus.c @@ -154,12 +154,20 @@ EXPORT_SYMBOL_GPL(typec_altmode_exit); * * Notifies the partner of @adev about Attention command. */ -void typec_altmode_attention(struct typec_altmode *adev, u32 vdo) +int typec_altmode_attention(struct typec_altmode *adev, u32 vdo) { - struct typec_altmode *pdev = &to_altmode(adev)->partner->adev; + struct altmode *partner = to_altmode(adev)->partner; + struct typec_altmode *pdev; + + if (!partner) + return -ENODEV; + + pdev = &partner->adev; if (pdev->ops && pdev->ops->attention) pdev->ops->attention(pdev, vdo); + + return 0; } EXPORT_SYMBOL_GPL(typec_altmode_attention); --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -1871,7 +1871,8 @@ static void tcpm_handle_vdm_request(stru } break; case ADEV_ATTENTION: - typec_altmode_attention(adev, p[1]); + if (typec_altmode_attention(adev, p[1])) + tcpm_log(port, "typec_altmode_attention no port partner altmode"); break; } } --- a/include/linux/usb/typec_altmode.h +++ b/include/linux/usb/typec_altmode.h @@ -67,7 +67,7 @@ struct typec_altmode_ops { int typec_altmode_enter(struct typec_altmode *altmode, u32 *vdo); int typec_altmode_exit(struct typec_altmode *altmode); -void typec_altmode_attention(struct typec_altmode *altmode, u32 vdo); +int typec_altmode_attention(struct typec_altmode *altmode, u32 vdo); int typec_altmode_vdm(struct typec_altmode *altmode, const u32 header, const u32 *vdo, int count); int typec_altmode_notify(struct typec_altmode *altmode, unsigned long conf,