From patchwork Fri Aug 6 16:40:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anirudh Rayabharam X-Patchwork-Id: 493566 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0CA37C432BE for ; Fri, 6 Aug 2021 16:40:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E095A611C5 for ; Fri, 6 Aug 2021 16:40:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232925AbhHFQk4 (ORCPT ); Fri, 6 Aug 2021 12:40:56 -0400 Received: from sender4-of-o53.zoho.com ([136.143.188.53]:21327 "EHLO sender4-of-o53.zoho.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232307AbhHFQky (ORCPT ); Fri, 6 Aug 2021 12:40:54 -0400 ARC-Seal: i=1; a=rsa-sha256; t=1628268032; cv=none; d=zohomail.com; s=zohoarc; b=VjQJn9Yo2OOs2lPyzpvrg2ToDE4Vp7D2uB0cA68eq8P+NJHkuvncFWhQOG0hGf1qlATGtouPxN7sPQwYow0U0S1VB5hgbDUUm2STg61vE0iMLlWZ3ToYLNerAyUgvixcgWS4olWVJKJ60IoSxLMGusVbPXQeghAspWjxUVeho34= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1628268032; h=Content-Transfer-Encoding:Cc:Date:From:MIME-Version:Message-ID:Subject:To; bh=U9Xt7jrxQ/s2c7DQyTWN6yPX3RSqwfnsXbplw4auAIs=; b=GVmCaGAQMDWJVUp8ajik39ajOVQyBNiy52AOcpdcqAr7xG1cPCyg9CK5uGqr1N4KXOx42bU8LKo1wDLlSldxruFNfCoOy/QeRNQ38aeTBm64LNCGE/jarK3ctStuQP/V/E6AIDiKgGtXMb1OgMUTVo1GuJAZFC6yvFv5lIFcCw4= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=anirudhrb.com; spf=pass smtp.mailfrom=mail@anirudhrb.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1628268032; s=zoho; d=anirudhrb.com; i=mail@anirudhrb.com; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version:Content-Transfer-Encoding; bh=U9Xt7jrxQ/s2c7DQyTWN6yPX3RSqwfnsXbplw4auAIs=; b=rmdYF9QZwZjLaNHbgvxOMTrM7e98RiqJCp861A2CcrgJcK2WXjz/ngQvOHopLw2u v4u+4dyvJ1zrXZGy6i3hWGp6pnZIi6iqpZf+d7uFP39houJq5roVmyNcQpNT/9BVbKL c5jWAse35mxLZTU1G34GIdhGm7/9Xf1IfVQrGgLM= Received: from localhost.localdomain (106.51.104.154 [106.51.104.154]) by mx.zohomail.com with SMTPS id 1628268027927634.6221552768395; Fri, 6 Aug 2021 09:40:27 -0700 (PDT) From: Anirudh Rayabharam To: Valentina Manea , Shuah Khan , Greg Kroah-Hartman Cc: linux-kernel-mentees@lists.linuxfoundation.org, Anirudh Rayabharam , syzbot+74d6ef051d3d2eacf428@syzkaller.appspotmail.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] usbip: give back URBs for unsent unlink requests during cleanup Date: Fri, 6 Aug 2021 22:10:14 +0530 Message-Id: <20210806164015.25263-1-mail@anirudhrb.com> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 X-ZohoMailClient: External Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org In vhci_device_unlink_cleanup(), the URBs for unsent unlink requests are not given back. This sometimes causes usb_kill_urb to wait indefinitely for that urb to be given back. syzbot has reported a hung task issue [1] for this. To fix this, give back the urbs corresponding to unsent unlink requests (unlink_tx list) similar to how urbs corresponding to unanswered unlink requests (unlink_rx list) are given back. Since the code is almost the same, extract it into a new function and call it for both unlink_rx and unlink_tx lists. [1]: https://syzkaller.appspot.com/bug?id=08f12df95ae7da69814e64eb5515d5a85ed06b76 Reported-by: syzbot+74d6ef051d3d2eacf428@syzkaller.appspotmail.com Tested-by: syzbot+74d6ef051d3d2eacf428@syzkaller.appspotmail.com Signed-off-by: Anirudh Rayabharam --- drivers/usb/usbip/vhci_hcd.c | 47 ++++++++++++++++++++++++++---------- 1 file changed, 34 insertions(+), 13 deletions(-) diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c index 4ba6bcdaa8e9..45f98aa12895 100644 --- a/drivers/usb/usbip/vhci_hcd.c +++ b/drivers/usb/usbip/vhci_hcd.c @@ -945,7 +945,8 @@ static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status) return 0; } -static void vhci_device_unlink_cleanup(struct vhci_device *vdev) +static void __vhci_cleanup_unlink_list(struct vhci_device *vdev, + struct list_head *unlink_list) { struct vhci_hcd *vhci_hcd = vdev_to_vhci_hcd(vdev); struct usb_hcd *hcd = vhci_hcd_to_hcd(vhci_hcd); @@ -953,23 +954,25 @@ static void vhci_device_unlink_cleanup(struct vhci_device *vdev) struct vhci_unlink *unlink, *tmp; unsigned long flags; + if (unlink_list != &vdev->unlink_tx + && unlink_list != &vdev->unlink_rx) { + pr_err("Invalid list passed to __vhci_cleanup_unlink_list\n"); + BUG(); + return; + } + spin_lock_irqsave(&vhci->lock, flags); spin_lock(&vdev->priv_lock); - list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) { - pr_info("unlink cleanup tx %lu\n", unlink->unlink_seqnum); - list_del(&unlink->list); - kfree(unlink); - } - - while (!list_empty(&vdev->unlink_rx)) { + list_for_each_entry_safe(unlink, tmp, unlink_list, list) { struct urb *urb; - unlink = list_first_entry(&vdev->unlink_rx, struct vhci_unlink, - list); - - /* give back URB of unanswered unlink request */ - pr_info("unlink cleanup rx %lu\n", unlink->unlink_seqnum); + if (unlink_list == &vdev->unlink_tx) + pr_info("unlink cleanup tx %lu\n", + unlink->unlink_seqnum); + else + pr_info("unlink cleanup rx %lu\n", + unlink->unlink_seqnum); urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum); if (!urb) { @@ -1001,6 +1004,24 @@ static void vhci_device_unlink_cleanup(struct vhci_device *vdev) spin_unlock_irqrestore(&vhci->lock, flags); } +static inline void vhci_cleanup_unlink_tx(struct vhci_device *vdev) +{ + __vhci_cleanup_unlink_list(vdev, &vdev->unlink_tx); +} + +static inline void vhci_cleanup_unlink_rx(struct vhci_device *vdev) +{ + __vhci_cleanup_unlink_list(vdev, &vdev->unlink_rx); +} + +static void vhci_device_unlink_cleanup(struct vhci_device *vdev) +{ + /* give back URBs of unsent unlink requests */ + vhci_cleanup_unlink_tx(vdev); + /* give back URBs of unanswered unlink requests */ + vhci_cleanup_unlink_rx(vdev); +} + /* * The important thing is that only one context begins cleanup. * This is why error handling and cleanup become simple.