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, URIBL_BLOCKED,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 B8B8EC433ED for ; Thu, 15 Apr 2021 14:55:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9C7B1613EE for ; Thu, 15 Apr 2021 14:55:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234184AbhDOOzw (ORCPT ); Thu, 15 Apr 2021 10:55:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:38804 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233985AbhDOOy0 (ORCPT ); Thu, 15 Apr 2021 10:54:26 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 338C9613ED; Thu, 15 Apr 2021 14:53:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1618498389; bh=9gomDYmU/NfEf4VVIGV9GU3X9p8r6Pk543CBJOuuVE4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cJZTW7MlYG1kZBnxLNxLm8DN7bO9FIJQud1kGbCCqTSg3M1xAyoArDi5R3B0NgkGL /BC2LeqbDYdL8lM89f4tcfG6aW79KIUu2KAhIVoG5FDJLofzIKRnCuHqGuxX22wHQ4 z67sUgQ7eeLSqc7VX8dc15z7pA3tInfSMMQei7f0= 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 4.14 20/68] usbip: synchronize event handler with sysfs code paths Date: Thu, 15 Apr 2021 16:47:01 +0200 Message-Id: <20210415144415.125445245@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210415144414.464797272@linuxfoundation.org> References: <20210415144414.464797272@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 @@ -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); }