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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 470E0C18E5A for ; Tue, 10 Mar 2020 13:20:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 163CC20409 for ; Tue, 10 Mar 2020 13:20:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583846433; bh=q3yD8SMbWAwNrT1iBJkEQAuuzq44A4f7dNbQy1ansmw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=q1zy7RXcaz3GACz06tGOAQlbKIh2/B9lOP8PY3fvr/RktOzZ8CymKPTKgOoBxeerP tu9Gj+49bkEbhkrZ4aUDtlEs0zg3tM2i80inQ0kfcKGkEBxUDOGg4zuYYlaoy5fWqt MkbMsmSL07vgG0Tzpq+vQgcJyZ9txZzvvkyd1t0M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729933AbgCJNUb (ORCPT ); Tue, 10 Mar 2020 09:20:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:52974 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730939AbgCJNHP (ORCPT ); Tue, 10 Mar 2020 09:07:15 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 555932469D; Tue, 10 Mar 2020 13:07:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583845634; bh=q3yD8SMbWAwNrT1iBJkEQAuuzq44A4f7dNbQy1ansmw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rLVCzYgaA0xGXpf8IWHn0dfEKL9YbXNCwNfEO8jjKAocrlAbsliwT9Xvs5ws0CEIy 7ffMDOoUTNfEiCNPecY/FBkhHCw4EuFmrjA0J90mtQe/P3AFhhjRAUg9ePxIKx+vPL J8j4VAnljv7QhBd1EWWYK3uwqfhZ3NOEbUP2a4zI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+784ccb935f9900cc7c9e@syzkaller.appspotmail.com, Alan Stern , Dan Carpenter , Jiri Kosina Subject: [PATCH 4.14 044/126] HID: hiddev: Fix race in in hiddev_disconnect() Date: Tue, 10 Mar 2020 13:41:05 +0100 Message-Id: <20200310124207.123826596@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200310124203.704193207@linuxfoundation.org> References: <20200310124203.704193207@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: dan.carpenter@oracle.com commit 5c02c447eaeda29d3da121a2e17b97ccaf579b51 upstream. Syzbot reports that "hiddev" is used after it's free in hiddev_disconnect(). The hiddev_disconnect() function sets "hiddev->exist = 0;" so hiddev_release() can free it as soon as we drop the "existancelock" lock. This patch moves the mutex_unlock(&hiddev->existancelock) until after we have finished using it. Reported-by: syzbot+784ccb935f9900cc7c9e@syzkaller.appspotmail.com Fixes: 7f77897ef2b6 ("HID: hiddev: fix potential use-after-free") Suggested-by: Alan Stern Signed-off-by: Dan Carpenter Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- drivers/hid/usbhid/hiddev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/hid/usbhid/hiddev.c +++ b/drivers/hid/usbhid/hiddev.c @@ -954,9 +954,9 @@ void hiddev_disconnect(struct hid_device hiddev->exist = 0; if (hiddev->open) { - mutex_unlock(&hiddev->existancelock); hid_hw_close(hiddev->hid); wake_up_interruptible(&hiddev->wait); + mutex_unlock(&hiddev->existancelock); } else { mutex_unlock(&hiddev->existancelock); kfree(hiddev);