From mboxrd@z Thu Jan 1 00:00:00 1970 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,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham 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 69764C43461 for ; Mon, 12 Apr 2021 08:43:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4B0E961221 for ; Mon, 12 Apr 2021 08:43:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237496AbhDLInW (ORCPT ); Mon, 12 Apr 2021 04:43:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:34888 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237477AbhDLInR (ORCPT ); Mon, 12 Apr 2021 04:43:17 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 59DD061244; Mon, 12 Apr 2021 08:42:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1618216979; bh=p2OwqxFHSKfHPF7Uh5dxXGlLivSDO5iVmkwk2ean3h4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=T8DuZ+DpCk/C0nyS8x4ucs7oSX73lEVb1Aaz92v2EkYAdcJ88urr02RFWe4AIMo2C RKetnlFN8MaueKN1AHkdhzuLN+E+UKPdm8XpwRujqQO39ccIV2Ft13EmTkL52gZuHM sH0CiHROa1zYpZ+9E7uW/+ZXAaCDG1dvB+PFIiHM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Shuah Khan , syzbot+a93fba6d384346a761e3@syzkaller.appspotmail.com Subject: [PATCH 4.19 25/66] usbip: synchronize event handler with sysfs code paths Date: Mon, 12 Apr 2021 10:40:31 +0200 Message-Id: <20210412083958.938940755@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210412083958.129944265@linuxfoundation.org> References: <20210412083958.129944265@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Shuah Khan commit 363eaa3a450abb4e63bd6e3ad79d1f7a0f717814 upstream. Fuzzing uncovered race condition between sysfs code paths in usbip drivers. Device connect/disconnect code paths initiated through sysfs interface are prone to races if disconnect happens during connect and vice versa. Use sysfs_lock to synchronize event handler with sysfs paths in usbip drivers. Cc: stable@vger.kernel.org Reported-and-tested-by: syzbot+a93fba6d384346a761e3@syzkaller.appspotmail.com Signed-off-by: Shuah Khan Link: https://lore.kernel.org/r/c5c8723d3f29dfe3d759cfaafa7dd16b0dfe2918.1616807117.git.skhan@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman --- drivers/usb/usbip/usbip_event.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/usb/usbip/usbip_event.c +++ b/drivers/usb/usbip/usbip_event.c @@ -70,6 +70,7 @@ static void event_handler(struct work_st while ((ud = get_event()) != NULL) { usbip_dbg_eh("pending event %lx\n", ud->event); + mutex_lock(&ud->sysfs_lock); /* * NOTE: shutdown must come first. * Shutdown the device. @@ -90,6 +91,7 @@ static void event_handler(struct work_st ud->eh_ops.unusable(ud); unset_event(ud, USBIP_EH_UNUSABLE); } + mutex_unlock(&ud->sysfs_lock); wake_up(&ud->eh_waitq); }