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 49D12C3F2D2 for ; Thu, 5 Mar 2020 17:14:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 18B0A24654 for ; Thu, 5 Mar 2020 17:14:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583428479; bh=hmXOjy2k2WuVXfJkljl/hOavvSMDuPfcrUAqlQP2Vrg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=HOTEr+IJeTRRgXw5ugexBIhOX3X1vitT2vrftudJp3Ug3og1FX2TC1rRRA5WcmWlz LzB5jILokcUsP0aJD+fqEM76OhpveidMiIGMDQKEYUPSGsMAu6147TVZa5Lq/iwQw2 UqSLhzDkG04H7zboyQ9Uch6BcRL4wUc4Z2o485sU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727731AbgCEROi (ORCPT ); Thu, 5 Mar 2020 12:14:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:40610 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727671AbgCERO2 (ORCPT ); Thu, 5 Mar 2020 12:14:28 -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 146E2208CD; Thu, 5 Mar 2020 17:14:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583428467; bh=hmXOjy2k2WuVXfJkljl/hOavvSMDuPfcrUAqlQP2Vrg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p1BL6T0bJZ1Dq8sRXuWhp10kydkdiqJ86z3wjCibTA453ZRhvgRkPf8treKIhZmjF CKqefeOCn+JKERGp9pSXULjExeQgllFIxY1YJ9HqB8rkLPf5Sj9ZG3FifQWuqz4moG y9mV91iEYfVk0nwdb9WBqPcA2w7TtpIIuB/KnMs0= 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 5.4 05/58] HID: hiddev: Fix race in in hiddev_disconnect() Date: Thu, 5 Mar 2020 12:13:26 -0500 Message-Id: <20200305171420.29595-5-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200305171420.29595-1-sashal@kernel.org> References: <20200305171420.29595-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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" [ 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 c879b214a4797..35b1fa6d962ec 100644 --- a/drivers/hid/usbhid/hiddev.c +++ b/drivers/hid/usbhid/hiddev.c @@ -941,9 +941,9 @@ 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