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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 C667DC43381 for ; Wed, 27 Mar 2019 18:50:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 99D1F205C9 for ; Wed, 27 Mar 2019 18:50:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553712624; bh=78TY9B7FO/efAFYSES5+blzMCIUbyaF7m4c+UxDdAQA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=nGb2QbHHTRWz4yQjboyVH7bhly3x/pAtR6eyr1t37l0ajw4gaVq8gwdHaads/5Tzj lTQSbEyV7CPtgDlKSbPGjHBkISKJWZl5eSrmpYwiteCeqgkonSrDbEziJhJHndW1RR ooCJ7l70YvgO+wUZfscdvj48x1NIlttruUIrfoBg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390487AbfC0SSU (ORCPT ); Wed, 27 Mar 2019 14:18:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:35182 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390479AbfC0SSU (ORCPT ); Wed, 27 Mar 2019 14:18:20 -0400 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 C968D217F5; Wed, 27 Mar 2019 18:18:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553710698; bh=78TY9B7FO/efAFYSES5+blzMCIUbyaF7m4c+UxDdAQA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rMLjTU0tUTbQcJZkTUnWy2CEfYqYZpyVDOS3vO9CYKbyAfHO54998zvCvpdAxqBAI v+si0IycCpIKuvTQazq5GAAQS+Ae2qdZY+ndeHnJa+VuSWTCc6Bxe9iTIlCn9z7HSd l4oc0hyfxBoU+Az9yN2gSxRSA2IU4wYGBsHeNlko= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jeremy Cline , Marcel Holtmann , Sasha Levin , linux-bluetooth@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 061/123] Bluetooth: hci_ldisc: Initialize hci_dev before open() Date: Wed, 27 Mar 2019 14:15:25 -0400 Message-Id: <20190327181628.15899-61-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190327181628.15899-1-sashal@kernel.org> References: <20190327181628.15899-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-bluetooth-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org From: Jeremy Cline [ Upstream commit 32a7b4cbe93b0a0ef7e63d31ca69ce54736c4412 ] The hci_dev struct hdev is referenced in work queues and timers started by open() in some protocols. This creates a race between the initialization function and the work or timer which can result hdev being dereferenced while it is still null. The syzbot report contains a reliable reproducer which causes a null pointer dereference of hdev in hci_uart_write_work() by making the memory allocation for hdev fail. To fix this, ensure hdev is valid from before calling a protocol's open() until after calling a protocol's close(). Reported-by: syzbot+257790c15bcdef6fe00c@syzkaller.appspotmail.com Signed-off-by: Jeremy Cline Signed-off-by: Marcel Holtmann Signed-off-by: Sasha Levin --- drivers/bluetooth/hci_ldisc.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c index 30bbe19b4b85..6a3a3011b38e 100644 --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -207,11 +207,11 @@ static void hci_uart_init_work(struct work_struct *work) err = hci_register_dev(hu->hdev); if (err < 0) { BT_ERR("Can't register HCI device"); + clear_bit(HCI_UART_PROTO_READY, &hu->flags); + hu->proto->close(hu); hdev = hu->hdev; hu->hdev = NULL; hci_free_dev(hdev); - clear_bit(HCI_UART_PROTO_READY, &hu->flags); - hu->proto->close(hu); return; } @@ -612,6 +612,7 @@ static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, static int hci_uart_register_dev(struct hci_uart *hu) { struct hci_dev *hdev; + int err; BT_DBG(""); @@ -655,11 +656,22 @@ static int hci_uart_register_dev(struct hci_uart *hu) else hdev->dev_type = HCI_PRIMARY; + /* Only call open() for the protocol after hdev is fully initialized as + * open() (or a timer/workqueue it starts) may attempt to reference it. + */ + err = hu->proto->open(hu); + if (err) { + hu->hdev = NULL; + hci_free_dev(hdev); + return err; + } + if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags)) return 0; if (hci_register_dev(hdev) < 0) { BT_ERR("Can't register HCI device"); + hu->proto->close(hu); hu->hdev = NULL; hci_free_dev(hdev); return -ENODEV; @@ -679,17 +691,12 @@ static int hci_uart_set_proto(struct hci_uart *hu, int id) if (!p) return -EPROTONOSUPPORT; - err = p->open(hu); - if (err) - return err; - hu->proto = p; set_bit(HCI_UART_PROTO_READY, &hu->flags); err = hci_uart_register_dev(hu); if (err) { clear_bit(HCI_UART_PROTO_READY, &hu->flags); - p->close(hu); return err; } -- 2.19.1