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=-19.0 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, URIBL_RED,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 74A0AC433B4 for ; Mon, 26 Apr 2021 07:34:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4AE52613AB for ; Mon, 26 Apr 2021 07:34:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232224AbhDZHew (ORCPT ); Mon, 26 Apr 2021 03:34:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:46064 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232681AbhDZHdn (ORCPT ); Mon, 26 Apr 2021 03:33:43 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8AEB5611CD; Mon, 26 Apr 2021 07:33:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1619422382; bh=zKOSe2vlocg7WUvmY+9ry+wdhhjgyeOWSVPmg63RPYw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mMY7LYzTmzcidDH9ih2j1Ao2HwA+kM500rIBwjogbvmJDqgS6Yh3BNk/h7MgnbEyn /Yyn+6N5K7XAgPMjU3pxauQD6mKf8zrwcTmLL74Zt8giIK+MfB49K0QItV9bp95mFH IBj8FH1MnMflBe3h2A5cSw0/u2/4ioqKsTu1kNnk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Shuah Khan , Tom Seewald , syzbot+a93fba6d384346a761e3@syzkaller.appspotmail.com Subject: [PATCH 4.9 27/37] usbip: synchronize event handler with sysfs code paths Date: Mon, 26 Apr 2021 09:29:28 +0200 Message-Id: <20210426072818.168255922@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210426072817.245304364@linuxfoundation.org> References: <20210426072817.245304364@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: linux-kernel@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 # 4.9.x 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: Tom Seewald 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 @@ -84,6 +84,7 @@ 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. @@ -104,6 +105,7 @@ 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); }