From patchwork Fri Aug 11 23:16:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luiz Augusto von Dentz X-Patchwork-Id: 712906 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 ABC32C001B0 for ; Fri, 11 Aug 2023 23:16:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229784AbjHKXQQ (ORCPT ); Fri, 11 Aug 2023 19:16:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229552AbjHKXQP (ORCPT ); Fri, 11 Aug 2023 19:16:15 -0400 Received: from mail-oa1-x33.google.com (mail-oa1-x33.google.com [IPv6:2001:4860:4864:20::33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A72F100 for ; Fri, 11 Aug 2023 16:16:14 -0700 (PDT) Received: by mail-oa1-x33.google.com with SMTP id 586e51a60fabf-1bbafe6fd8fso2141604fac.3 for ; Fri, 11 Aug 2023 16:16:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1691795773; x=1692400573; h=content-transfer-encoding:mime-version:message-id:date:subject:to :from:from:to:cc:subject:date:message-id:reply-to; bh=txaNYPFjoKE5LMPZMX//vYXsFHC4qgE/scux8+LFxzM=; b=O3NPduVdN9W0rf7XeU+hM8B6cZq++DMHPoqRtyeyHqsAqdm2n7pSEyYoV0Q6LK14gr NWJd7h8qz/DyKAgVwezxExIIP+W8DBSf7iXTE/750yVHTWtZAcqtxq438ta++YHQYHD7 1yAm4B293Mo3mQ77KKWKhCNigCJa6HB/TAulpzhzV4UFY+eUXM9e9lMTFcg4YaSgUUbb CrLWjubcYFPBPAl5g8+YWf4RacTC5zMVW0B82EmCZdDJrYnrGWK7+V13PihBVHrA2V2c qlxEK9CISzfQb9H2yOSkbhiagCxv9n2S6SEkQGZj6EwcyQvU630kyeLR+9SmfHRDur6p Sa9A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691795773; x=1692400573; h=content-transfer-encoding:mime-version:message-id:date:subject:to :from:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=txaNYPFjoKE5LMPZMX//vYXsFHC4qgE/scux8+LFxzM=; b=ASBKOAgPj59VNtJL2/SWVTGhPVztfehGOLGCD7REfvry5ztesbAWJe842LzppNpDp9 IscK+gkyHzokyPnI3Wm6JpIo1Bv86Rs3DBfOMwmZSLKN1Dl+8fmX/8qirswHaTjO+Yne 8uDw0SukRoSThuTAPX60VVZRiRcu22MHXDeAQXhyk52mf+bwZV0CeXa9hIv8GqXN7FES +pd5UcEoS9YSf0L6DBBClvpq0FkQYOZ8WrrSQPHO4LeSjtWET6c+aXCDtAV/RpkvziE/ AU6V4Hxrmb7pGwauFgFj8KvbMMxtb5YDAKYbw59Lqd9FvYM1RwJkruU5zoOjR0fZD4Fz RhtQ== X-Gm-Message-State: AOJu0YzsaijLcbHy7QHY3rOcS7xjwhU8pYsJLjS56SYuDd6N5x/+GrkZ 1ZdaKGo5xAIA4hgsHu/3aJUpzuwtwX0= X-Google-Smtp-Source: AGHT+IFZtM3rawPc3QE2aD1OeyAIfYH6mmWmJEEKzFqrDL4kJ3iqzrV25Fcb81OMhZTJ68Cdnf70nw== X-Received: by 2002:a05:6870:8301:b0:1be:f46d:a26c with SMTP id p1-20020a056870830100b001bef46da26cmr3710058oae.27.1691795773013; Fri, 11 Aug 2023 16:16:13 -0700 (PDT) Received: from lvondent-mobl4.. (c-98-232-221-87.hsd1.or.comcast.net. [98.232.221.87]) by smtp.gmail.com with ESMTPSA id 8-20020a17090a198800b00262fc3d911esm6118791pji.28.2023.08.11.16.16.11 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Aug 2023 16:16:11 -0700 (PDT) From: Luiz Augusto von Dentz To: linux-bluetooth@vger.kernel.org Subject: [PATCH v3] Bluetooth: hci_sync: Fix UAF in hci_disconnect_all_sync Date: Fri, 11 Aug 2023 16:16:10 -0700 Message-ID: <20230811231610.2025814-1-luiz.dentz@gmail.com> X-Mailer: git-send-email 2.41.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org From: Luiz Augusto von Dentz Use-after-free can occur in hci_disconnect_all_sync if a connection is deleted by concurrent processing of a controller event. To prevent this the code now tries to iterate over the list backwards to ensure the links are cleanup before its parents, also it no longer relies on a cursor, instead it always uses the last element since hci_abort_conn_sync is guaranteed to call hci_conn_del. 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 Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/hci_sync.c | 51 ++++++++++++++++++++++++---------------- 1 file changed, 31 insertions(+), 20 deletions(-) diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c index 5eb30ba21370..86e18e09136e 100644 --- a/net/bluetooth/hci_sync.c +++ b/net/bluetooth/hci_sync.c @@ -5370,6 +5370,7 @@ int hci_abort_conn_sync(struct hci_dev *hdev, struct hci_conn *conn, u8 reason) { int err = 0; u16 handle = conn->handle; + struct hci_conn *c; switch (conn->state) { case BT_CONNECTED: @@ -5389,43 +5390,53 @@ int hci_abort_conn_sync(struct hci_dev *hdev, struct hci_conn *conn, u8 reason) hci_dev_unlock(hdev); return 0; default: + hci_dev_lock(hdev); conn->state = BT_CLOSED; + hci_disconn_cfm(conn, reason); + hci_conn_del(conn); + hci_dev_unlock(hdev); return 0; } + /* Check if the connection hasn't been cleanup while waiting + * commands to complete. + */ + c = hci_conn_hash_lookup_handle(hdev, handle); + if (!c || c != conn) + return 0; + /* Cleanup hci_conn object if it cannot be cancelled as it * likelly means the controller and host stack are out of sync * or in case of LE it was still scanning so it can be cleanup * safely. */ - if (err) { - struct hci_conn *c; - - /* Check if the connection hasn't been cleanup while waiting - * commands to complete. - */ - c = hci_conn_hash_lookup_handle(hdev, handle); - if (!c || c != conn) - return 0; - - hci_dev_lock(hdev); - hci_conn_failed(conn, err); - hci_dev_unlock(hdev); - } + hci_dev_lock(hdev); + hci_conn_failed(conn, reason); + hci_dev_unlock(hdev); return err; } static int hci_disconnect_all_sync(struct hci_dev *hdev, u8 reason) { - struct hci_conn *conn, *tmp; - int err; + struct list_head *head = &hdev->conn_hash.list; + struct hci_conn *conn; - 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(); + while ((conn = list_first_or_null_rcu(head, struct hci_conn, list))) { + /* Make sure the connection is not freed while unlocking */ + conn = hci_conn_get(conn); + rcu_read_unlock(); + /* Disregard possible errors since hci_conn_del shall have been + * called even in case of errors had occurred since it would + * then cause hci_conn_failed to be called which calls + * hci_conn_del internally. + */ + hci_abort_conn_sync(hdev, conn, reason); + hci_conn_put(conn); + rcu_read_lock(); } + rcu_read_unlock(); return 0; }