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=-19.1 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=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 59422C433EF for ; Mon, 13 Sep 2021 14:35:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3AF2660E08 for ; Mon, 13 Sep 2021 14:35:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344492AbhIMOgo (ORCPT ); Mon, 13 Sep 2021 10:36:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:51902 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244972AbhIMOas (ORCPT ); Mon, 13 Sep 2021 10:30:48 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 16D3661BA7; Mon, 13 Sep 2021 13:51:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1631541092; bh=Ny8wVJn4A9i6ipl3UIAXM88BcEFMhX2inpmHcX3ehGo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FAEwDmqrKhyGubcgeDVlnuyY2DZha7bY4xVf/sGMv7nCXobB1xbtVhZQHqyYxm6Wk AuMUsI4a/E6f1pp/QPVlY0at6/ODrXIL/p9BoN/3FDirvl3nMSQbb5vqq9+hNCIfWh AXzkgdQR77BvR5tE7YoIiCbVqpiSvfDPXPKFe+RA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dongliang Mu , Sean Young , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 5.14 159/334] media: em28xx-input: fix refcount bug in em28xx_usb_disconnect Date: Mon, 13 Sep 2021 15:13:33 +0200 Message-Id: <20210913131118.730235772@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210913131113.390368911@linuxfoundation.org> References: <20210913131113.390368911@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: Dongliang Mu [ Upstream commit 6fa54bc713c262e1cfbc5613377ef52280d7311f ] If em28xx_ir_init fails, it would decrease the refcount of dev. However, in the em28xx_ir_fini, when ir is NULL, it goes to ref_put and decrease the refcount of dev. This will lead to a refcount bug. Fix this bug by removing the kref_put in the error handling code of em28xx_ir_init. refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 7 at lib/refcount.c:28 refcount_warn_saturate+0x18e/0x1a0 lib/refcount.c:28 Modules linked in: CPU: 0 PID: 7 Comm: kworker/0:1 Not tainted 5.13.0 #3 Workqueue: usb_hub_wq hub_event RIP: 0010:refcount_warn_saturate+0x18e/0x1a0 lib/refcount.c:28 Call Trace: kref_put.constprop.0+0x60/0x85 include/linux/kref.h:69 em28xx_usb_disconnect.cold+0xd7/0xdc drivers/media/usb/em28xx/em28xx-cards.c:4150 usb_unbind_interface+0xbf/0x3a0 drivers/usb/core/driver.c:458 __device_release_driver drivers/base/dd.c:1201 [inline] device_release_driver_internal+0x22a/0x230 drivers/base/dd.c:1232 bus_remove_device+0x108/0x160 drivers/base/bus.c:529 device_del+0x1fe/0x510 drivers/base/core.c:3540 usb_disable_device+0xd1/0x1d0 drivers/usb/core/message.c:1419 usb_disconnect+0x109/0x330 drivers/usb/core/hub.c:2221 hub_port_connect drivers/usb/core/hub.c:5151 [inline] hub_port_connect_change drivers/usb/core/hub.c:5440 [inline] port_event drivers/usb/core/hub.c:5586 [inline] hub_event+0xf81/0x1d40 drivers/usb/core/hub.c:5668 process_one_work+0x2c9/0x610 kernel/workqueue.c:2276 process_scheduled_works kernel/workqueue.c:2338 [inline] worker_thread+0x333/0x5b0 kernel/workqueue.c:2424 kthread+0x188/0x1d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Reported-by: Dongliang Mu Fixes: ac5688637144 ("media: em28xx: Fix possible memory leak of em28xx struct") Signed-off-by: Dongliang Mu Signed-off-by: Sean Young Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/usb/em28xx/em28xx-input.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/media/usb/em28xx/em28xx-input.c b/drivers/media/usb/em28xx/em28xx-input.c index 59529cbf9cd0..0b6d77c3bec8 100644 --- a/drivers/media/usb/em28xx/em28xx-input.c +++ b/drivers/media/usb/em28xx/em28xx-input.c @@ -842,7 +842,6 @@ error: kfree(ir); ref_put: em28xx_shutdown_buttons(dev); - kref_put(&dev->ref, em28xx_free_device); return err; } -- 2.30.2