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=-16.7 required=3.0 tests=BAYES_00, 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 A354FC433FE for ; Thu, 10 Dec 2020 15:44:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5EB1E2067B for ; Thu, 10 Dec 2020 15:44:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391922AbgLJPo1 (ORCPT ); Thu, 10 Dec 2020 10:44:27 -0500 Received: from mail.kernel.org ([198.145.29.99]:47412 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391247AbgLJOjw (ORCPT ); Thu, 10 Dec 2020 09:39:52 -0500 From: Greg Kroah-Hartman Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paulian Bogdan Marinca , Mika Westerberg Subject: [PATCH 5.9 33/75] thunderbolt: Fix use-after-free in remove_unplugged_switch() Date: Thu, 10 Dec 2020 15:26:58 +0100 Message-Id: <20201210142607.691475078@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201210142606.074509102@linuxfoundation.org> References: <20201210142606.074509102@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: Mika Westerberg commit 600c0849cf86b75d86352f59745226273290986a upstream. Paulian reported a crash that happens when a dock is unplugged during hibernation: [78436.228217] thunderbolt 0-1: device disconnected [78436.228365] BUG: kernel NULL pointer dereference, address: 00000000000001e0 ... [78436.228397] RIP: 0010:icm_free_unplugged_children+0x109/0x1a0 ... [78436.228432] Call Trace: [78436.228439] icm_rescan_work+0x24/0x30 [78436.228444] process_one_work+0x1a3/0x3a0 [78436.228449] worker_thread+0x30/0x370 [78436.228454] ? process_one_work+0x3a0/0x3a0 [78436.228457] kthread+0x13d/0x160 [78436.228461] ? kthread_park+0x90/0x90 [78436.228465] ret_from_fork+0x1f/0x30 This happens because remove_unplugged_switch() calls tb_switch_remove() that releases the memory pointed by sw so the following lines reference to a memory that might be released already. Fix this by saving pointer to the parent device before calling tb_switch_remove(). Reported-by: Paulian Bogdan Marinca Fixes: 4f7c2e0d8765 ("thunderbolt: Make sure device runtime resume completes before taking domain lock") Cc: stable@vger.kernel.org Signed-off-by: Mika Westerberg Reviewed-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- drivers/thunderbolt/icm.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/drivers/thunderbolt/icm.c +++ b/drivers/thunderbolt/icm.c @@ -1973,7 +1973,9 @@ static int complete_rpm(struct device *d static void remove_unplugged_switch(struct tb_switch *sw) { - pm_runtime_get_sync(sw->dev.parent); + struct device *parent = get_device(sw->dev.parent); + + pm_runtime_get_sync(parent); /* * Signal this and switches below for rpm_complete because @@ -1984,8 +1986,10 @@ static void remove_unplugged_switch(stru bus_for_each_dev(&tb_bus_type, &sw->dev, NULL, complete_rpm); tb_switch_remove(sw); - pm_runtime_mark_last_busy(sw->dev.parent); - pm_runtime_put_autosuspend(sw->dev.parent); + pm_runtime_mark_last_busy(parent); + pm_runtime_put_autosuspend(parent); + + put_device(parent); } static void icm_free_unplugged_children(struct tb_switch *sw)