From patchwork Sun Aug 6 20:18:38 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pauli Virtanen X-Patchwork-Id: 710988 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 67C05C41513 for ; Sun, 6 Aug 2023 20:20:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229999AbjHFUU1 (ORCPT ); Sun, 6 Aug 2023 16:20:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58946 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229503AbjHFUU0 (ORCPT ); Sun, 6 Aug 2023 16:20:26 -0400 Received: from lahtoruutu.iki.fi (lahtoruutu.iki.fi [185.185.170.37]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C5AF1721 for ; Sun, 6 Aug 2023 13:20:23 -0700 (PDT) Received: from monolith.lan (unknown [193.138.7.198]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: pav) by lahtoruutu.iki.fi (Postfix) with ESMTPSA id 4RJrRV1jBpz49Q4L; Sun, 6 Aug 2023 23:20:22 +0300 (EEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=iki.fi; s=lahtoruutu; t=1691353222; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3q+xHwPvfdebNrGao4COGz1LFLBg1RSl7sHHGQU5F2A=; b=k+AHcpHB5GX7gYcuECgyKzJX3rKAfSiH1BBqTs9h8fBArL2R90JD7BTQyj75sdyJTjjRCA P9lxQxNVCJXgnvD00QV3g9NpwxuW+j5pUgb0VmXgNgy3zVEWHsIwChmtHdu6a3n4WPboD0 h/VT6cn8BUl89fnFDz8GQ/K8BdUVLuEBMsg/hkHRxXxJqVTLFmxvWvDdB5O6MpLVav4lhy t+pXJcZGv8upHPr8XHhzzwHgUlLBUHO9DrHcZVGzEGfeqQpNRApRANOUlhKLLnN1thGNHj J2ig1pD0X283NHc4Ng9mo4KquJr9OCWBpY+uF0oHCOvLIbFrsOotCzm28JEAIg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=iki.fi; s=lahtoruutu; t=1691353222; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3q+xHwPvfdebNrGao4COGz1LFLBg1RSl7sHHGQU5F2A=; b=n8vAK+fTjqstv2Ft5L1oI/WqXvLhL/Fctws1Px/huG+0IX/sedYs/sB9qF9KEkY0kCGkZm JE4AOoGtHGe5cEbrk5kId1iDRqR61xJ0jP5nuaubWRRVimC73iKZYMlVCDFJStVFP57agi Lx62t9v/7r4XFDvVKflDs/+RR6J9UqhA0e8D3DoEHbhqoVvhx0xTYlNAWswPtT2bLKb1CE Nb7bGztIX8YCVXQhqd2/RwBuhK+WMjG8/FrVBl1Z3moGAUX2ItGYCDCeWYN+PLRt9exBKv 8UMo5UdpmYDBVlZOTqMB+0YXCofDT6WEQ3b71LntS5HUJjKWJaiezHnbQK3ehQ== ARC-Authentication-Results: i=1; ORIGINATING; auth=pass smtp.auth=pav smtp.mailfrom=pav@iki.fi ARC-Seal: i=1; s=lahtoruutu; d=iki.fi; t=1691353222; a=rsa-sha256; cv=none; b=r6JAgiZkt8RR9P0ohCe0BFbaRWVCs7w/7sCvlI95GDyC7Lv3QYsFJEMQq7yzb6LMUn2W4z h1rtG7zw7xjyXeFszdelHkYy5Az5dbS6aqis0xQvQGwqaxrDMf+LRpC/UVp0mGUx0m2Ttb GHluGKP92NsW4QAALJ2fWVp3eTKcNUAgpB+b7JwD0SEMk+ZMc8DdKzUESXm9WaVh0/6tmp OMv8qtOSq/aXQiLShRo9JbSbU6Eij/WVWhL2jOdczZI5Fh2+BauIMFicnLru87gklYR0Cm WYyWVJL+U3z4Bz7ryWJudVt0OwpwreuYXf+Kf2zxi8ol+6aMxVkkdcQSc5UC9w== From: Pauli Virtanen To: linux-bluetooth@vger.kernel.org Cc: Pauli Virtanen Subject: [PATCH v2 2/4] Bluetooth: hci_sync: fix use-after-free in hci_disconnect_all_sync Date: Sun, 6 Aug 2023 23:18:38 +0300 Message-ID: <7b81cf669e2172b2e69d3b4fe6c9c256f5249c69.1691352503.git.pav@iki.fi> X-Mailer: git-send-email 2.41.0 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org Use-after-free occurs in hci_disconnect_all_sync if a connection is deleted by concurrent processing of a controller event. This can occur while waiting for controller events (big time window) or at other times (less likely). Fix the iteration in hci_disconnect_all_sync to allow hci_conn to be deleted at any time. UAF crash log: ================================================================== BUG: KASAN: slab-use-after-free in hci_set_powered_sync (net/bluetooth/hci_sync.c:5424) [bluetooth] Read of size 8 at addr ffff888009d9c000 by task kworker/u9:0/124 CPU: 0 PID: 124 Comm: kworker/u9:0 Tainted: G W 6.5.0-rc1+ #10 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014 Workqueue: hci0 hci_cmd_sync_work [bluetooth] Call Trace: dump_stack_lvl+0x5b/0x90 print_report+0xcf/0x670 ? __virt_addr_valid+0xdd/0x160 ? hci_set_powered_sync+0x2c9/0x4a0 [bluetooth] kasan_report+0xa6/0xe0 ? hci_set_powered_sync+0x2c9/0x4a0 [bluetooth] ? __pfx_set_powered_sync+0x10/0x10 [bluetooth] hci_set_powered_sync+0x2c9/0x4a0 [bluetooth] ? __pfx_hci_set_powered_sync+0x10/0x10 [bluetooth] ? __pfx_lock_release+0x10/0x10 ? __pfx_set_powered_sync+0x10/0x10 [bluetooth] hci_cmd_sync_work+0x137/0x220 [bluetooth] process_one_work+0x526/0x9d0 ? __pfx_process_one_work+0x10/0x10 ? __pfx_do_raw_spin_lock+0x10/0x10 ? mark_held_locks+0x1a/0x90 worker_thread+0x92/0x630 ? __pfx_worker_thread+0x10/0x10 kthread+0x196/0x1e0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2c/0x50 Allocated by task 1782: kasan_save_stack+0x33/0x60 kasan_set_track+0x25/0x30 __kasan_kmalloc+0x8f/0xa0 hci_conn_add+0xa5/0xa80 [bluetooth] hci_bind_cis+0x881/0x9b0 [bluetooth] iso_connect_cis+0x121/0x520 [bluetooth] iso_sock_connect+0x3f6/0x790 [bluetooth] __sys_connect+0x109/0x130 __x64_sys_connect+0x40/0x50 do_syscall_64+0x60/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Freed by task 695: kasan_save_stack+0x33/0x60 kasan_set_track+0x25/0x30 kasan_save_free_info+0x2b/0x50 __kasan_slab_free+0x10a/0x180 __kmem_cache_free+0x14d/0x2e0 device_release+0x5d/0xf0 kobject_put+0xdf/0x270 hci_disconn_complete_evt+0x274/0x3a0 [bluetooth] hci_event_packet+0x579/0x7e0 [bluetooth] hci_rx_work+0x287/0xaa0 [bluetooth] process_one_work+0x526/0x9d0 worker_thread+0x92/0x630 kthread+0x196/0x1e0 ret_from_fork+0x2c/0x50 ================================================================== Fixes: 182ee45da083 ("Bluetooth: hci_sync: Rework hci_suspend_notifier") Signed-off-by: Pauli Virtanen --- Notes: v2: use only valid values for abort_reason, in case we fail before handling all conns This is still a bit clumsy, a separate flag indicating if connection was aborted yet could be better. net/bluetooth/hci_sync.c | 47 ++++++++++++++++++++++++++++++++++------ 1 file changed, 40 insertions(+), 7 deletions(-) diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c index 51ff682f66e0..228259f44815 100644 --- a/net/bluetooth/hci_sync.c +++ b/net/bluetooth/hci_sync.c @@ -5415,16 +5415,49 @@ int hci_abort_conn_sync(struct hci_dev *hdev, struct hci_conn *conn, u8 reason) static int hci_disconnect_all_sync(struct hci_dev *hdev, u8 reason) { - struct hci_conn *conn, *tmp; - int err; + struct hci_conn *c, *conn; + int err = 0; - list_for_each_entry_safe(conn, tmp, &hdev->conn_hash.list, list) { - err = hci_abort_conn_sync(hdev, conn, reason); - if (err) - return err; + rcu_read_lock(); + + /* Any conn may be gone while waiting for events, iterate safely. + * If conn is in conn_hash and we didn't abort it, it probably + * has not yet been aborted. + */ + list_for_each_entry_rcu(c, &hdev->conn_hash.list, list) { + if (c->abort_reason != reason) + continue; + + c->abort_reason = (reason != HCI_ERROR_REMOTE_USER_TERM) ? + HCI_ERROR_REMOTE_USER_TERM : HCI_ERROR_UNSPECIFIED; } - return 0; + do { + conn = NULL; + list_for_each_entry_rcu(c, &hdev->conn_hash.list, list) { + if (c->abort_reason == reason) + continue; + + conn = c; + break; + } + if (!conn) + break; + + conn->abort_reason = reason; + hci_conn_get(conn); + + rcu_read_unlock(); + + err = hci_abort_conn_sync(hdev, conn, reason); + hci_conn_put(conn); + + rcu_read_lock(); + } while (!err); + + rcu_read_unlock(); + + return err; } /* This function perform power off HCI command sequence as follows: