From patchwork Mon Aug 14 18:05:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: RD Babiera X-Patchwork-Id: 714010 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 33DF4C41513 for ; Mon, 14 Aug 2023 18:08:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230226AbjHNSHn (ORCPT ); Mon, 14 Aug 2023 14:07:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52040 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230086AbjHNSHK (ORCPT ); Mon, 14 Aug 2023 14:07:10 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 25FF2E61 for ; Mon, 14 Aug 2023 11:07:09 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id 3f1490d57ef6-d61e9cb310dso5234022276.0 for ; Mon, 14 Aug 2023 11:07:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1692036428; x=1692641228; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=ILL3/wme+Xj3iELICcc/rzQVuKV1rDXNge6KvsnjpQU=; b=byqR1Ww+0r/eXw/qhFsThHdhUozBD7vXDz8QBlKVU7ODMahemj/tryCgsp4E4moyVo Y6WIvCu4UBQCyYP5mYnIz14yhVEqF0KWZo78E+i/dl/n9UFjqYadCSAb3JQTWyuXtDvT 4UJd1fX5GS4LxUOCNLGiW26cx5vZ9VE9JB4mVqHFhkCZn5wP8QNDqPLg11wcW+C04Jz3 +rcvEt4yROAK69LcpGxkVyx+x5gT0zv8M+aMV5dZ4uUnSekygISfLbwjVe+6MzvzbUfG F4m09HWA7nxzK5jOFjK4r6EXvYW1uUC8pipTpQCpkwumrAI+6q7TQSgAzntNvfUSGgth qBDA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692036428; x=1692641228; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=ILL3/wme+Xj3iELICcc/rzQVuKV1rDXNge6KvsnjpQU=; b=gCpc8YxHKva4ilpEpXiPqjitNmGa46FiA1KqDbyR2lXxkWU9ZRMtpGLbuv8P1yb8Tf wqcKKqGdKmzvplmBnAd9DRqfeQLvx705Mbn8C0tJSzsSx2mNdOu58sfNsESHYpOeSoyF dg22CQPSa7oXNu6zxusZwevYaJVGfzARWfe3IWvL3TaZqAYi3iGrOjQVkzVGDi3dSt6/ ETXuBSAQ//+Dl+OOB1VA2z7tw9DeLJm1oSxg9UyiuBZe3eN6A5kxGrjqdN5Sph2IskBU Qf8FY4jtvsDUObtVrJ+ijJfpE6gdnCCsKzoR4D+SO7tn5JmXxUaqE0lbr3AS2D1SNRay nk9Q== X-Gm-Message-State: AOJu0YxsHZsBtNfYMuj7VPHJ1PR+SNMrVr+FZLUlAmHum85PN7WH8Xo2 gda+Nc5VhJJQwdC38y86R6j+kMBHg2iPQq8= X-Google-Smtp-Source: AGHT+IFPcHmzG6KqaH70vqmY/Q2yqgXqnRgdvqHi7Ao2JTUETR1j90+egJ02S9qBGbxPNcRQs1E46IszPQ13uZA= X-Received: from rdbabiera.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:18a8]) (user=rdbabiera job=sendgmr) by 2002:a25:d4d5:0:b0:d0f:bcfe:bc74 with SMTP id m204-20020a25d4d5000000b00d0fbcfebc74mr138892ybf.9.1692036428382; Mon, 14 Aug 2023 11:07:08 -0700 (PDT) Date: Mon, 14 Aug 2023 18:05:59 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.41.0.694.ge786442a9b-goog Message-ID: <20230814180559.923475-1-rdbabiera@google.com> Subject: [PATCH v4] usb: typec: bus: verify partner exists in typec_altmode_attention From: RD Babiera To: heikki.krogerus@linux.intel.com, gregkh@linuxfoundation.org, linux@roeck-us.net Cc: badhri@google.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, RD Babiera , stable@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org 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 --- Changes since v1: * Only assigns pdev if altmode partner exists in typec_altmode_attention * Removed error return in typec_altmode_attention if Alt Mode does not implement Attention messages. * Changed tcpm_log message to indicate that altmode partner does not exist, as it only logs in that case. --- Changes since v2: * Changed tcpm_log message to accurately reflect error * Revised commit message --- Changes since v3: * Fixed nits --- 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(-) base-commit: f176638af476c6d46257cc3303f5c7cf47d5967d diff --git a/drivers/usb/typec/bus.c b/drivers/usb/typec/bus.c index fe5b9a2e61f5..e95ec7e382bb 100644 --- a/drivers/usb/typec/bus.c +++ b/drivers/usb/typec/bus.c @@ -183,12 +183,20 @@ 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); diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index 5a7d8cc04628..77fe16190766 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -1877,7 +1877,8 @@ static void tcpm_handle_vdm_request(struct tcpm_port *port, } 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; } } diff --git a/include/linux/usb/typec_altmode.h b/include/linux/usb/typec_altmode.h index 350d49012659..28aeef8f9e7b 100644 --- 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,