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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 CA2A6C3F2D2 for ; Thu, 5 Mar 2020 17:18:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9A624207FD for ; Thu, 5 Mar 2020 17:18:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583428733; bh=7SaziNVYYG4I60nOloOeJp1riuc/CPAPo3yiqECQ7jY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=oknFpfn5jyz37wxcHiILbQSJ9J9/wroEjZIBMAcHfdRV6XuqsYAKo8mGNsbs5Euhl Hg1ETzbt2aWjez9K4bQ77pUeEmEmqVnoKuRtiwEEwQQBDulfwbRDeLxsKKQC9m7hNX fvAjHQke8pCjpwHsicgqN4bPUQ31svubBa4YPMOg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728048AbgCERPY (ORCPT ); Thu, 5 Mar 2020 12:15:24 -0500 Received: from mail.kernel.org ([198.145.29.99]:42138 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728043AbgCERPY (ORCPT ); Thu, 5 Mar 2020 12:15:24 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4EB5C2166E; Thu, 5 Mar 2020 17:15:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583428523; bh=7SaziNVYYG4I60nOloOeJp1riuc/CPAPo3yiqECQ7jY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Hx2oPhwDdqlAtUdcic1F53D/myENJkYXU9yCp5klTIlbeQsPPZz0aX96qmkLY7aDg a+waCSMs9MFNjLVG3RUrBgEVZISp5G6Q3qlN5v/jHpDGYw9PCpwwkwrq5Bkoa4lR8j wv5tGU/ClfOJ1yb4+3L+sYMSqBt1bc8WZT/Vr4og= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "dan.carpenter@oracle.com" , syzbot+784ccb935f9900cc7c9e@syzkaller.appspotmail.com, Alan Stern , Jiri Kosina , Sasha Levin , linux-usb@vger.kernel.org, linux-input@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 05/31] HID: hiddev: Fix race in in hiddev_disconnect() Date: Thu, 5 Mar 2020 12:14:49 -0500 Message-Id: <20200305171516.30028-5-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200305171516.30028-1-sashal@kernel.org> References: <20200305171516.30028-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org From: "dan.carpenter@oracle.com" [ Upstream commit 5c02c447eaeda29d3da121a2e17b97ccaf579b51 ] 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: Sasha Levin --- drivers/hid/usbhid/hiddev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c index da000195b79af..c34ef95d7cef3 100644 --- a/drivers/hid/usbhid/hiddev.c +++ b/drivers/hid/usbhid/hiddev.c @@ -954,9 +954,9 @@ void hiddev_disconnect(struct hid_device *hid) 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); -- 2.20.1