From patchwork Tue Jun 13 18:06:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pauli Virtanen X-Patchwork-Id: 692700 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 5EB86EB64DA for ; Tue, 13 Jun 2023 18:06:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231941AbjFMSGT (ORCPT ); Tue, 13 Jun 2023 14:06:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49232 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230108AbjFMSGQ (ORCPT ); Tue, 13 Jun 2023 14:06:16 -0400 Received: from meesny.iki.fi (meesny.iki.fi [IPv6:2001:67c:2b0:1c1::201]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 00D3E19B2 for ; Tue, 13 Jun 2023 11:06:10 -0700 (PDT) Received: from monolith.lan (91-152-120-101.elisa-laajakaista.fi [91.152.120.101]) (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 meesny.iki.fi (Postfix) with ESMTPSA id 4Qgc1X4HXBz100v; Tue, 13 Jun 2023 21:06:08 +0300 (EEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=iki.fi; s=meesny; t=1686679568; 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=lxQRFWLS30If5FnTA2pJHQPuZggXlTJP+zNr6Zw8fFo=; b=eDY1ahGGX57xhsFcEjF8ZDL/jBXeqcdAAlJx6trk3OnJ/s+0o+jEZwvPJDYgKySytiCp5r NHmuSvsoFIssaFTD5sgbbWkIVglsLBp7lKR7rVO4fIDne4RuHh5rNo5h4nblMPf2m/1HTI GJDw33xVQAWAe4YM+Nnhz6ir1KKXOkc= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=iki.fi; s=meesny; t=1686679568; 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=lxQRFWLS30If5FnTA2pJHQPuZggXlTJP+zNr6Zw8fFo=; b=CUmiIq6K6YV/aV5z7WlWpcZBUjalHrDIg9l4Sy+A7eDQtcAWlar7FKdsTpOZ86jKxy84Gb iPYKtiayTxOEFMsDAr9LVx6zc0wmAsiEvAl22AIJFg7QYarcM/Xoo803aO1F7y9q4B/stW ehhSZh0ZzWvJZjOQJRL+RIQSBgp2xuA= ARC-Authentication-Results: i=1; ORIGINATING; auth=pass smtp.auth=pav smtp.mailfrom=pav@iki.fi ARC-Seal: i=1; s=meesny; d=iki.fi; t=1686679568; a=rsa-sha256; cv=none; b=VBepXH/nPiPJSthuhmyVieCJF3QSBkuw1OUQ8gwqGTHc4rbn73J2HcMvXLz23AX38iv9Go N9wI39/M2L5gTunzcDQL6KwLNjMaeizlNrMGOL8kq06TUqZWEX8kfYwYiWyEkrtxkQE0WE x+Y/aJSop2rfFq8G434KOq9vXhE+G2Q= From: Pauli Virtanen To: linux-bluetooth@vger.kernel.org Cc: Pauli Virtanen Subject: [PATCH v2 1/3] Bluetooth: use RCU for hci_conn_params and iterate safely in hci_sync Date: Tue, 13 Jun 2023 21:06:02 +0300 Message-Id: X-Mailer: git-send-email 2.40.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org hci_update_accept_list_sync iterates over hdev->pend_le_conns and hdev->pend_le_reports, and waits for controller events in the loop body, without holding hdev lock. Meanwhile, these lists and the items may be modified e.g. by le_scan_cleanup. This can invalidate the list cursor in the ongoing iterations, resulting to invalid behavior (eg use-after-free). Use RCU for the hci_conn_params action lists. Since the loop bodies in hci_sync block and we cannot use RCU for the whole loop, add hci_conn_params.add_pending to keep track which items are left. Copy data to avoid needing lock on hci_conn_params. Only the flags field is written from elsewhere, so READ_ONCE/WRITE_ONCE should guarantee we read valid values. Free params everywhere with hci_conn_params_free so the cleanup is guaranteed to be done properly. This fixes the following, which can be triggered at least by changing hci_le_set_cig_params to always return false, and running BlueZ iso-tester, which causes connections to be created and dropped fast: ================================================================== BUG: KASAN: slab-use-after-free in hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2536 net/bluetooth/hci_sync.c:2723 net/bluetooth/hci_sync.c:2841) Read of size 8 at addr ffff888001265018 by task kworker/u3:0/32 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014 Workqueue: hci0 hci_cmd_sync_work Call Trace: dump_stack_lvl (./arch/x86/include/asm/irqflags.h:134 lib/dump_stack.c:107) print_report (mm/kasan/report.c:320 mm/kasan/report.c:430) ? __virt_addr_valid (./include/linux/mmzone.h:1915 ./include/linux/mmzone.h:2011 arch/x86/mm/physaddr.c:65) ? hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2536 net/bluetooth/hci_sync.c:2723 net/bluetooth/hci_sync.c:2841) kasan_report (mm/kasan/report.c:538) ? hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2536 net/bluetooth/hci_sync.c:2723 net/bluetooth/hci_sync.c:2841) hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2536 net/bluetooth/hci_sync.c:2723 net/bluetooth/hci_sync.c:2841) ? __pfx_hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2780) ? mutex_lock (kernel/locking/mutex.c:282) ? __pfx_mutex_lock (kernel/locking/mutex.c:282) ? __pfx_mutex_unlock (kernel/locking/mutex.c:538) ? __pfx_update_passive_scan_sync (net/bluetooth/hci_sync.c:2861) hci_cmd_sync_work (net/bluetooth/hci_sync.c:306) process_one_work (./arch/x86/include/asm/preempt.h:27 kernel/workqueue.c:2399) worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2538) ? __pfx_worker_thread (kernel/workqueue.c:2480) kthread (kernel/kthread.c:376) ? __pfx_kthread (kernel/kthread.c:331) ret_from_fork (arch/x86/entry/entry_64.S:314) Allocated by task 31: kasan_save_stack (mm/kasan/common.c:46) kasan_set_track (mm/kasan/common.c:52) __kasan_kmalloc (mm/kasan/common.c:374 mm/kasan/common.c:383) hci_conn_params_add (./include/linux/slab.h:580 ./include/linux/slab.h:720 net/bluetooth/hci_core.c:2277) hci_connect_le_scan (net/bluetooth/hci_conn.c:1419 net/bluetooth/hci_conn.c:1589) hci_connect_cis (net/bluetooth/hci_conn.c:2266) iso_connect_cis (net/bluetooth/iso.c:390) iso_sock_connect (net/bluetooth/iso.c:899) __sys_connect (net/socket.c:2003 net/socket.c:2020) __x64_sys_connect (net/socket.c:2027) do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) Freed by task 15: kasan_save_stack (mm/kasan/common.c:46) kasan_set_track (mm/kasan/common.c:52) kasan_save_free_info (mm/kasan/generic.c:523) __kasan_slab_free (mm/kasan/common.c:238 mm/kasan/common.c:200 mm/kasan/common.c:244) __kmem_cache_free (mm/slub.c:1807 mm/slub.c:3787 mm/slub.c:3800) hci_conn_params_del (net/bluetooth/hci_core.c:2323) le_scan_cleanup (net/bluetooth/hci_conn.c:202) process_one_work (./arch/x86/include/asm/preempt.h:27 kernel/workqueue.c:2399) worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2538) kthread (kernel/kthread.c:376) ret_from_fork (arch/x86/entry/entry_64.S:314) ================================================================== Fixes: e8907f76544f ("Bluetooth: hci_sync: Make use of hci_cmd_sync_queue set 3") Signed-off-by: Pauli Virtanen --- Notes: v2: use RCU include/net/bluetooth/hci_core.h | 5 ++ net/bluetooth/hci_conn.c | 9 ++-- net/bluetooth/hci_core.c | 34 +++++++++--- net/bluetooth/hci_event.c | 12 ++--- net/bluetooth/hci_sync.c | 93 ++++++++++++++++++++++++++++---- net/bluetooth/mgmt.c | 30 +++++------ 6 files changed, 141 insertions(+), 42 deletions(-) diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h index 683666ea210c..8c6ac6d29c62 100644 --- a/include/net/bluetooth/hci_core.h +++ b/include/net/bluetooth/hci_core.h @@ -822,6 +822,8 @@ struct hci_conn_params { struct hci_conn *conn; bool explicit_connect; + /* Accessed without hdev->lock: */ + bool add_pending; hci_conn_flags_t flags; u8 privacy_mode; }; @@ -1605,6 +1607,9 @@ struct hci_conn_params *hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type); void hci_conn_params_del(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type); void hci_conn_params_clear_disabled(struct hci_dev *hdev); +void hci_conn_params_free(struct hci_conn_params *param); +void hci_conn_params_set_pending(struct hci_conn_params *param, + struct list_head *list); struct hci_conn_params *hci_pend_le_action_lookup(struct list_head *list, bdaddr_t *addr, diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c index 7d4941e6dbdf..ae9a35d1405b 100644 --- a/net/bluetooth/hci_conn.c +++ b/net/bluetooth/hci_conn.c @@ -118,7 +118,7 @@ static void hci_connect_le_scan_cleanup(struct hci_conn *conn, u8 status) */ params->explicit_connect = false; - list_del_init(¶ms->action); + hci_conn_params_set_pending(params, NULL); switch (params->auto_connect) { case HCI_AUTO_CONN_EXPLICIT: @@ -127,10 +127,10 @@ static void hci_connect_le_scan_cleanup(struct hci_conn *conn, u8 status) return; case HCI_AUTO_CONN_DIRECT: case HCI_AUTO_CONN_ALWAYS: - list_add(¶ms->action, &hdev->pend_le_conns); + hci_conn_params_set_pending(params, &hdev->pend_le_conns); break; case HCI_AUTO_CONN_REPORT: - list_add(¶ms->action, &hdev->pend_le_reports); + hci_conn_params_set_pending(params, &hdev->pend_le_reports); break; default: break; @@ -1435,8 +1435,7 @@ static int hci_explicit_conn_params_set(struct hci_dev *hdev, if (params->auto_connect == HCI_AUTO_CONN_DISABLED || params->auto_connect == HCI_AUTO_CONN_REPORT || params->auto_connect == HCI_AUTO_CONN_EXPLICIT) { - list_del_init(¶ms->action); - list_add(¶ms->action, &hdev->pend_le_conns); + hci_conn_params_set_pending(params, &hdev->pend_le_conns); } params->explicit_connect = true; diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 48917c68358d..7992a61fe1fd 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -2249,21 +2249,41 @@ struct hci_conn_params *hci_conn_params_lookup(struct hci_dev *hdev, return NULL; } -/* This function requires the caller holds hdev->lock */ +/* This function requires the caller holds hdev->lock or rcu_read_lock */ struct hci_conn_params *hci_pend_le_action_lookup(struct list_head *list, bdaddr_t *addr, u8 addr_type) { struct hci_conn_params *param; - list_for_each_entry(param, list, action) { + rcu_read_lock(); + + list_for_each_entry_rcu(param, list, action) { if (bacmp(¶m->addr, addr) == 0 && - param->addr_type == addr_type) + param->addr_type == addr_type) { + rcu_read_unlock(); return param; + } } + rcu_read_unlock(); + return NULL; } +/* This function requires the caller holds hdev->lock */ +void hci_conn_params_set_pending(struct hci_conn_params *param, + struct list_head *list) +{ + if (!list_empty(¶m->action)) { + list_del_rcu(¶m->action); + synchronize_rcu(); + INIT_LIST_HEAD(¶m->action); + } + + if (list) + list_add_rcu(¶m->action, list); +} + /* This function requires the caller holds hdev->lock */ struct hci_conn_params *hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type) @@ -2297,14 +2317,15 @@ struct hci_conn_params *hci_conn_params_add(struct hci_dev *hdev, return params; } -static void hci_conn_params_free(struct hci_conn_params *params) +void hci_conn_params_free(struct hci_conn_params *params) { + hci_conn_params_set_pending(params, NULL); + if (params->conn) { hci_conn_drop(params->conn); hci_conn_put(params->conn); } - list_del(¶ms->action); list_del(¶ms->list); kfree(params); } @@ -2342,8 +2363,7 @@ void hci_conn_params_clear_disabled(struct hci_dev *hdev) continue; } - list_del(¶ms->list); - kfree(params); + hci_conn_params_free(params); } BT_DBG("All LE disabled connection parameters were removed"); diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 7c199f7361f7..8187c9f827fa 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -1564,7 +1564,7 @@ static u8 hci_cc_le_set_privacy_mode(struct hci_dev *hdev, void *data, params = hci_conn_params_lookup(hdev, &cp->bdaddr, cp->bdaddr_type); if (params) - params->privacy_mode = cp->mode; + WRITE_ONCE(params->privacy_mode, cp->mode); hci_dev_unlock(hdev); @@ -2804,8 +2804,8 @@ static void hci_cs_disconnect(struct hci_dev *hdev, u8 status) case HCI_AUTO_CONN_DIRECT: case HCI_AUTO_CONN_ALWAYS: - list_del_init(¶ms->action); - list_add(¶ms->action, &hdev->pend_le_conns); + hci_conn_params_set_pending(params, + &hdev->pend_le_conns); break; default: @@ -3423,8 +3423,8 @@ static void hci_disconn_complete_evt(struct hci_dev *hdev, void *data, case HCI_AUTO_CONN_DIRECT: case HCI_AUTO_CONN_ALWAYS: - list_del_init(¶ms->action); - list_add(¶ms->action, &hdev->pend_le_conns); + hci_conn_params_set_pending(params, + &hdev->pend_le_conns); hci_update_passive_scan(hdev); break; @@ -5972,7 +5972,7 @@ static void le_conn_complete_evt(struct hci_dev *hdev, u8 status, params = hci_pend_le_action_lookup(&hdev->pend_le_conns, &conn->dst, conn->dst_type); if (params) { - list_del_init(¶ms->action); + hci_conn_params_set_pending(params, NULL); if (params->conn) { hci_conn_drop(params->conn); hci_conn_put(params->conn); diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c index 97da5bcaa904..da12e286ee64 100644 --- a/net/bluetooth/hci_sync.c +++ b/net/bluetooth/hci_sync.c @@ -2160,15 +2160,23 @@ static int hci_le_del_accept_list_sync(struct hci_dev *hdev, return 0; } +struct conn_params { + bdaddr_t addr; + u8 addr_type; + hci_conn_flags_t flags; + u8 privacy_mode; +}; + /* Adds connection to resolve list if needed. * Setting params to NULL programs local hdev->irk */ static int hci_le_add_resolve_list_sync(struct hci_dev *hdev, - struct hci_conn_params *params) + struct conn_params *params) { struct hci_cp_le_add_to_resolv_list cp; struct smp_irk *irk; struct bdaddr_list_with_irk *entry; + struct hci_conn_params *p; if (!use_ll_privacy(hdev)) return 0; @@ -2203,6 +2211,16 @@ static int hci_le_add_resolve_list_sync(struct hci_dev *hdev, /* Default privacy mode is always Network */ params->privacy_mode = HCI_NETWORK_PRIVACY; + rcu_read_lock(); + p = hci_pend_le_action_lookup(&hdev->pend_le_conns, + ¶ms->addr, params->addr_type); + if (!p) + p = hci_pend_le_action_lookup(&hdev->pend_le_reports, + ¶ms->addr, params->addr_type); + if (p) + WRITE_ONCE(p->privacy_mode, HCI_NETWORK_PRIVACY); + rcu_read_unlock(); + done: if (hci_dev_test_flag(hdev, HCI_PRIVACY)) memcpy(cp.local_irk, hdev->irk, 16); @@ -2215,7 +2233,7 @@ static int hci_le_add_resolve_list_sync(struct hci_dev *hdev, /* Set Device Privacy Mode. */ static int hci_le_set_privacy_mode_sync(struct hci_dev *hdev, - struct hci_conn_params *params) + struct conn_params *params) { struct hci_cp_le_set_privacy_mode cp; struct smp_irk *irk; @@ -2240,6 +2258,8 @@ static int hci_le_set_privacy_mode_sync(struct hci_dev *hdev, bacpy(&cp.bdaddr, &irk->bdaddr); cp.mode = HCI_DEVICE_PRIVACY; + /* Note: params->privacy_mode is not updated since it is a copy */ + return __hci_cmd_sync_status(hdev, HCI_OP_LE_SET_PRIVACY_MODE, sizeof(cp), &cp, HCI_CMD_TIMEOUT); } @@ -2249,7 +2269,7 @@ static int hci_le_set_privacy_mode_sync(struct hci_dev *hdev, * properly set the privacy mode. */ static int hci_le_add_accept_list_sync(struct hci_dev *hdev, - struct hci_conn_params *params, + struct conn_params *params, u8 *num_entries) { struct hci_cp_le_add_to_accept_list cp; @@ -2447,6 +2467,51 @@ struct sk_buff *hci_read_local_oob_data_sync(struct hci_dev *hdev, return __hci_cmd_sync_sk(hdev, opcode, 0, NULL, 0, HCI_CMD_TIMEOUT, sk); } +static void conn_params_add_iter_init(struct list_head *list) +{ + struct hci_conn_params *params; + + rcu_read_lock(); + + list_for_each_entry_rcu(params, list, action) + params->add_pending = true; + + rcu_read_unlock(); +} + +static bool conn_params_add_iter_next(struct list_head *list, + struct conn_params *item) +{ + struct hci_conn_params *params; + + rcu_read_lock(); + + list_for_each_entry_rcu(params, list, action) { + if (!params->add_pending) + continue; + + /* No hdev->lock, but: addr, addr_type are immutable. + * privacy_mode is only written by us or in + * hci_cc_le_set_privacy_mode that we wait for. + * We should be idempotent so MGMT updating flags + * while we are processing is OK. + */ + bacpy(&item->addr, ¶ms->addr); + item->addr_type = params->addr_type; + item->flags = READ_ONCE(params->flags); + item->privacy_mode = READ_ONCE(params->privacy_mode); + + params->add_pending = false; + + rcu_read_unlock(); + return true; + } + + rcu_read_unlock(); + + return false; +} + /* Device must not be scanning when updating the accept list. * * Update is done using the following sequence: @@ -2466,7 +2531,7 @@ struct sk_buff *hci_read_local_oob_data_sync(struct hci_dev *hdev, */ static u8 hci_update_accept_list_sync(struct hci_dev *hdev) { - struct hci_conn_params *params; + struct conn_params params; struct bdaddr_list *b, *t; u8 num_entries = 0; bool pend_conn, pend_report; @@ -2504,6 +2569,7 @@ static u8 hci_update_accept_list_sync(struct hci_dev *hdev) if (hci_conn_hash_lookup_le(hdev, &b->bdaddr, b->bdaddr_type)) continue; + /* Pointers not dereferenced, no locks needed */ pend_conn = hci_pend_le_action_lookup(&hdev->pend_le_conns, &b->bdaddr, b->bdaddr_type); @@ -2532,9 +2598,15 @@ static u8 hci_update_accept_list_sync(struct hci_dev *hdev) * available accept list entries in the controller, then * just abort and return filer policy value to not use the * accept list. + * + * The list and params may be mutated while we wait for events, + * so use special iteration with copies. */ - list_for_each_entry(params, &hdev->pend_le_conns, action) { - err = hci_le_add_accept_list_sync(hdev, params, &num_entries); + + conn_params_add_iter_init(&hdev->pend_le_conns); + + while (conn_params_add_iter_next(&hdev->pend_le_conns, ¶ms)) { + err = hci_le_add_accept_list_sync(hdev, ¶ms, &num_entries); if (err) goto done; } @@ -2543,8 +2615,11 @@ static u8 hci_update_accept_list_sync(struct hci_dev *hdev) * the list of pending reports and also add these to the * accept list if there is still space. Abort if space runs out. */ - list_for_each_entry(params, &hdev->pend_le_reports, action) { - err = hci_le_add_accept_list_sync(hdev, params, &num_entries); + + conn_params_add_iter_init(&hdev->pend_le_reports); + + while (conn_params_add_iter_next(&hdev->pend_le_reports, ¶ms)) { + err = hci_le_add_accept_list_sync(hdev, ¶ms, &num_entries); if (err) goto done; } @@ -4837,12 +4912,12 @@ static void hci_pend_le_actions_clear(struct hci_dev *hdev) struct hci_conn_params *p; list_for_each_entry(p, &hdev->le_conn_params, list) { + hci_conn_params_set_pending(p, NULL); if (p->conn) { hci_conn_drop(p->conn); hci_conn_put(p->conn); p->conn = NULL; } - list_del_init(&p->action); } BT_DBG("All LE pending actions cleared"); diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index 61c8e1b8f3b0..b35b1c685b86 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -1303,15 +1303,15 @@ static void restart_le_actions(struct hci_dev *hdev) /* Needed for AUTO_OFF case where might not "really" * have been powered off. */ - list_del_init(&p->action); + hci_conn_params_set_pending(p, NULL); switch (p->auto_connect) { case HCI_AUTO_CONN_DIRECT: case HCI_AUTO_CONN_ALWAYS: - list_add(&p->action, &hdev->pend_le_conns); + hci_conn_params_set_pending(p, &hdev->pend_le_conns); break; case HCI_AUTO_CONN_REPORT: - list_add(&p->action, &hdev->pend_le_reports); + hci_conn_params_set_pending(p, &hdev->pend_le_reports); break; default: break; @@ -5175,7 +5175,7 @@ static int set_device_flags(struct sock *sk, struct hci_dev *hdev, void *data, goto unlock; } - params->flags = current_flags; + WRITE_ONCE(params->flags, current_flags); status = MGMT_STATUS_SUCCESS; /* Update passive scan if HCI_CONN_FLAG_DEVICE_PRIVACY @@ -7586,7 +7586,7 @@ static int hci_conn_params_set(struct hci_dev *hdev, bdaddr_t *addr, if (params->auto_connect == auto_connect) return 0; - list_del_init(¶ms->action); + hci_conn_params_set_pending(params, NULL); switch (auto_connect) { case HCI_AUTO_CONN_DISABLED: @@ -7595,18 +7595,22 @@ static int hci_conn_params_set(struct hci_dev *hdev, bdaddr_t *addr, * connect to device, keep connecting. */ if (params->explicit_connect) - list_add(¶ms->action, &hdev->pend_le_conns); + hci_conn_params_set_pending(params, + &hdev->pend_le_conns); break; case HCI_AUTO_CONN_REPORT: if (params->explicit_connect) - list_add(¶ms->action, &hdev->pend_le_conns); + hci_conn_params_set_pending(params, + &hdev->pend_le_conns); else - list_add(¶ms->action, &hdev->pend_le_reports); + hci_conn_params_set_pending(params, + &hdev->pend_le_reports); break; case HCI_AUTO_CONN_DIRECT: case HCI_AUTO_CONN_ALWAYS: if (!is_connected(hdev, addr, addr_type)) - list_add(¶ms->action, &hdev->pend_le_conns); + hci_conn_params_set_pending(params, + &hdev->pend_le_conns); break; } @@ -7829,9 +7833,7 @@ static int remove_device(struct sock *sk, struct hci_dev *hdev, goto unlock; } - list_del(¶ms->action); - list_del(¶ms->list); - kfree(params); + hci_conn_params_free(params); device_removed(sk, hdev, &cp->addr.bdaddr, cp->addr.type); } else { @@ -7862,9 +7864,7 @@ static int remove_device(struct sock *sk, struct hci_dev *hdev, p->auto_connect = HCI_AUTO_CONN_EXPLICIT; continue; } - list_del(&p->action); - list_del(&p->list); - kfree(p); + hci_conn_params_free(p); } bt_dev_dbg(hdev, "All LE connection parameters were removed"); From patchwork Tue Jun 13 18:06:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pauli Virtanen X-Patchwork-Id: 692701 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 3C6F9EB64D8 for ; Tue, 13 Jun 2023 18:06:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231840AbjFMSGR (ORCPT ); Tue, 13 Jun 2023 14:06:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49230 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230462AbjFMSGP (ORCPT ); Tue, 13 Jun 2023 14:06:15 -0400 Received: from meesny.iki.fi (meesny.iki.fi [IPv6:2001:67c:2b0:1c1::201]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F3EEE19B1 for ; Tue, 13 Jun 2023 11:06:10 -0700 (PDT) Received: from monolith.lan (91-152-120-101.elisa-laajakaista.fi [91.152.120.101]) (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 meesny.iki.fi (Postfix) with ESMTPSA id 4Qgc1Y0tCxz1016; Tue, 13 Jun 2023 21:06:09 +0300 (EEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=iki.fi; s=meesny; t=1686679569; 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=MMkx3MMhFVCti2aTyzxtfPJqeA/J5JTxrn4m+6aEISs=; b=av0KGDub068qKmRDtM5UWllEtlhm2gCw8QL1g1pYUl63nTT4leNfzHC7rQWGP/zGzOYgac yJsbMqOSsl+M5wK+b2gjgQ5S7JDa55iNPQrETQQKH33ALa6EpRiOJPZdvhJXz+ZUi7z8i6 FDbtw+saH+Fd9wgOpGKPDx5Lw2Ef4Fg= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=iki.fi; s=meesny; t=1686679569; 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=MMkx3MMhFVCti2aTyzxtfPJqeA/J5JTxrn4m+6aEISs=; b=FMXNJNZYIykCmNDBTcgO6zhgGUfY62gOIAzRfhAGF+/M+crqQf4YebydOtCaxAlFsl3zPU CqDCzzGw+QcT99Ob2WEWzhc4fTPh0iGOCHHrDAmMZrhGruHady+IVNS6YegpzmsNnUtDSg AHRcJW1GScRwmlRYrNKzJ5zCNtUX1Eo= ARC-Authentication-Results: i=1; ORIGINATING; auth=pass smtp.auth=pav smtp.mailfrom=pav@iki.fi ARC-Seal: i=1; s=meesny; d=iki.fi; t=1686679569; a=rsa-sha256; cv=none; b=B6NU0Us86ya9JGeTbm4TEzG7Mx7D5+hvO2idPWH7Y0rP9Z+XkkUkw7n4aaKL54vpmmPfXV 6l4pZUOwAG2r05kEYuSee0ufH3iA62/fHGw3IvN85ZHjhp9apZH3xrwS952ArtXcY+Z7Xy sdMqlYTCuWck36ne6VIvb96m89V7ZM0= From: Pauli Virtanen To: linux-bluetooth@vger.kernel.org Cc: Pauli Virtanen Subject: [PATCH v2 2/3] Bluetooth: hci_event: call disconnect callback before deleting conn Date: Tue, 13 Jun 2023 21:06:03 +0300 Message-Id: <35ee31b8c22cfe9e53675183d314c1f0b64e3ac0.1686589290.git.pav@iki.fi> X-Mailer: git-send-email 2.40.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org In hci_cs_disconnect, we do hci_conn_del even if disconnection failed. ISO, L2CAP and SCO connections refer to the hci_conn without hci_conn_get, so disconn_cfm must be called so they can clean up their conn, otherwise use-after-free occurs. ISO: ========================================================== iso_sock_connect:880: sk 00000000eabd6557 iso_connect_cis:356: 70:1a:b8:98:ff:a2 -> 28:3d:c2:4a:7e:da ... iso_conn_add:140: hcon 000000001696f1fd conn 00000000b6251073 hci_dev_put:1487: hci0 orig refcnt 17 __iso_chan_add:214: conn 00000000b6251073 iso_sock_clear_timer:117: sock 00000000eabd6557 state 3 ... hci_rx_work:4085: hci0 Event packet hci_event_packet:7601: hci0: event 0x0f hci_cmd_status_evt:4346: hci0: opcode 0x0406 hci_cs_disconnect:2760: hci0: status 0x0c hci_sent_cmd_data:3107: hci0 opcode 0x0406 hci_conn_del:1151: hci0 hcon 000000001696f1fd handle 2560 hci_conn_unlink:1102: hci0: hcon 000000001696f1fd hci_conn_drop:1451: hcon 00000000d8521aaf orig refcnt 2 hci_chan_list_flush:2780: hcon 000000001696f1fd hci_dev_put:1487: hci0 orig refcnt 21 hci_dev_put:1487: hci0 orig refcnt 20 hci_req_cmd_complete:3978: opcode 0x0406 status 0x0c ... ... iso_sock_sendmsg:1098: sock 00000000dea5e2e0, sk 00000000eabd6557 BUG: kernel NULL pointer dereference, address: 0000000000000668 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014 RIP: 0010:iso_sock_sendmsg (net/bluetooth/iso.c:1112) bluetooth ========================================================== L2CAP: ================================================================== hci_cmd_status_evt:4359: hci0: opcode 0x0406 hci_cs_disconnect:2760: hci0: status 0x0c hci_sent_cmd_data:3085: hci0 opcode 0x0406 hci_conn_del:1151: hci0 hcon ffff88800c999000 handle 3585 hci_conn_unlink:1102: hci0: hcon ffff88800c999000 hci_chan_list_flush:2780: hcon ffff88800c999000 hci_chan_del:2761: hci0 hcon ffff88800c999000 chan ffff888018ddd280 ... BUG: KASAN: slab-use-after-free in hci_send_acl+0x2d/0x540 [bluetooth] Read of size 8 at addr ffff888018ddd298 by task bluetoothd/1175 CPU: 0 PID: 1175 Comm: bluetoothd Tainted: G E 6.4.0-rc4+ #2 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014 Call Trace: dump_stack_lvl+0x5b/0x90 print_report+0xcf/0x670 ? __virt_addr_valid+0xf8/0x180 ? hci_send_acl+0x2d/0x540 [bluetooth] kasan_report+0xa8/0xe0 ? hci_send_acl+0x2d/0x540 [bluetooth] hci_send_acl+0x2d/0x540 [bluetooth] ? __pfx___lock_acquire+0x10/0x10 l2cap_chan_send+0x1fd/0x1300 [bluetooth] ? l2cap_sock_sendmsg+0xf2/0x170 [bluetooth] ? __pfx_l2cap_chan_send+0x10/0x10 [bluetooth] ? lock_release+0x1d5/0x3c0 ? mark_held_locks+0x1a/0x90 l2cap_sock_sendmsg+0x100/0x170 [bluetooth] sock_write_iter+0x275/0x280 ? __pfx_sock_write_iter+0x10/0x10 ? __pfx___lock_acquire+0x10/0x10 do_iter_readv_writev+0x176/0x220 ? __pfx_do_iter_readv_writev+0x10/0x10 ? find_held_lock+0x83/0xa0 ? selinux_file_permission+0x13e/0x210 do_iter_write+0xda/0x340 vfs_writev+0x1b4/0x400 ? __pfx_vfs_writev+0x10/0x10 ? __seccomp_filter+0x112/0x750 ? populate_seccomp_data+0x182/0x220 ? __fget_light+0xdf/0x100 ? do_writev+0x19d/0x210 do_writev+0x19d/0x210 ? __pfx_do_writev+0x10/0x10 ? mark_held_locks+0x1a/0x90 do_syscall_64+0x60/0x90 ? lockdep_hardirqs_on_prepare+0x149/0x210 ? do_syscall_64+0x6c/0x90 ? lockdep_hardirqs_on_prepare+0x149/0x210 entry_SYSCALL_64_after_hwframe+0x72/0xdc RIP: 0033:0x7ff45cb23e64 Code: 15 d1 1f 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 80 3d 9d a7 0d 00 00 74 13 b8 14 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89 RSP: 002b:00007fff21ae09b8 EFLAGS: 00000202 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007ff45cb23e64 RDX: 0000000000000001 RSI: 00007fff21ae0aa0 RDI: 0000000000000017 RBP: 00007fff21ae0aa0 R08: 000000000095a8a0 R09: 0000607000053f40 R10: 0000000000000001 R11: 0000000000000202 R12: 00007fff21ae0ac0 R13: 00000fffe435c150 R14: 00007fff21ae0a80 R15: 000060f000000040 Allocated by task 771: kasan_save_stack+0x33/0x60 kasan_set_track+0x25/0x30 __kasan_kmalloc+0xaa/0xb0 hci_chan_create+0x67/0x1b0 [bluetooth] l2cap_conn_add.part.0+0x17/0x590 [bluetooth] l2cap_connect_cfm+0x266/0x6b0 [bluetooth] hci_le_remote_feat_complete_evt+0x167/0x310 [bluetooth] hci_event_packet+0x38d/0x800 [bluetooth] hci_rx_work+0x287/0xb20 [bluetooth] process_one_work+0x4f7/0x970 worker_thread+0x8f/0x620 kthread+0x17f/0x1c0 ret_from_fork+0x2c/0x50 Freed by task 771: kasan_save_stack+0x33/0x60 kasan_set_track+0x25/0x30 kasan_save_free_info+0x2e/0x50 ____kasan_slab_free+0x169/0x1c0 slab_free_freelist_hook+0x9e/0x1c0 __kmem_cache_free+0xc0/0x310 hci_chan_list_flush+0x46/0x90 [bluetooth] hci_conn_cleanup+0x7d/0x330 [bluetooth] hci_cs_disconnect+0x35d/0x530 [bluetooth] hci_cmd_status_evt+0xef/0x2b0 [bluetooth] hci_event_packet+0x38d/0x800 [bluetooth] hci_rx_work+0x287/0xb20 [bluetooth] process_one_work+0x4f7/0x970 worker_thread+0x8f/0x620 kthread+0x17f/0x1c0 ret_from_fork+0x2c/0x50 ================================================================== Fixes: b8d290525e39 ("Bluetooth: clean up connection in hci_cs_disconnect") Signed-off-by: Pauli Virtanen --- Notes: v2: call disconn_cfm for all conn types, as L2CAP also crashes. Correct commit in Fixes tag. net/bluetooth/hci_event.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 8187c9f827fa..a6dabc5b6fad 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -2784,6 +2784,9 @@ static void hci_cs_disconnect(struct hci_dev *hdev, u8 status) hci_enable_advertising(hdev); } + /* Inform sockets conn is gone before we delete it */ + hci_disconn_cfm(conn, HCI_ERROR_UNSPECIFIED); + goto done; } From patchwork Tue Jun 13 18:06:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pauli Virtanen X-Patchwork-Id: 692179 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 74871EB64D7 for ; Tue, 13 Jun 2023 18:06:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231931AbjFMSGS (ORCPT ); Tue, 13 Jun 2023 14:06:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49230 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229630AbjFMSGQ (ORCPT ); Tue, 13 Jun 2023 14:06:16 -0400 Received: from meesny.iki.fi (meesny.iki.fi [195.140.195.201]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DCA0019A8 for ; Tue, 13 Jun 2023 11:06:10 -0700 (PDT) Received: from monolith.lan (91-152-120-101.elisa-laajakaista.fi [91.152.120.101]) (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 meesny.iki.fi (Postfix) with ESMTPSA id 4Qgc1Y25g5z10MP; Tue, 13 Jun 2023 21:06:09 +0300 (EEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=iki.fi; s=meesny; t=1686679569; 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=A88fH+WVTfME8Ra4Drw+Ud5TSkQO5GNvM/Shcwais9w=; b=Ow/YcC40506svU97MaNFqHFX/Bp3En1jDPp+9jN0bKpIKcZhQ3x61/4BziBJrFXFrm4gIx gvp4qctClbZC5aFVv0UOdIyPSBhRNwVZtEbEpTFMPp1Inar93yDVX8Wyrs9BaL3u6OCekp zogCBrVjFa9yiifXbiVdmPUeFuu7LUI= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=iki.fi; s=meesny; t=1686679569; 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=A88fH+WVTfME8Ra4Drw+Ud5TSkQO5GNvM/Shcwais9w=; b=hgwL59+8QY96QUlinwFhfj81qQZaLjw6QLdeZvnCj+sAno29SmG3JUXQ0T1Ca36vU25YVF n13FwHPvny3FM8vHqgER+YH22VzzDx5RBeW8i8eVhkfh44FGXpCq2uhgd0B05phWVX35sH +NxYgwE2MOoIUfGHIL7DBFlTbtF2Ocs= ARC-Authentication-Results: i=1; ORIGINATING; auth=pass smtp.auth=pav smtp.mailfrom=pav@iki.fi ARC-Seal: i=1; s=meesny; d=iki.fi; t=1686679569; a=rsa-sha256; cv=none; b=Wj+TBaK3GGuNXJ95hfa0gAYTL5fT59mQF5QjkzuPWzlQ22QUvdPy2r/2Ds8efeR8amQrRZ zNWnfbh4mISjZA2r/Xy4U3NHm5zs0sDslmDT5xkTU4yKqdBYAceaBos472vRuXKAXqneht 642GnnVy7E9keZBP+wAeJX+bM0Yuup8= From: Pauli Virtanen To: linux-bluetooth@vger.kernel.org Cc: Pauli Virtanen Subject: [PATCH v2 3/3] Bluetooth: ISO: fix iso_conn related locking and validity issues Date: Tue, 13 Jun 2023 21:06:04 +0300 Message-Id: <3a0cbe341bd6051ffcd58d3abef6800f9f2615ff.1686589290.git.pav@iki.fi> X-Mailer: git-send-email 2.40.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org sk->sk_state indicates whether iso_pi(sk)->conn is valid. Operations that check/update sk_state and access conn should hold lock_sock, otherwise they can race. The order of taking locks is hci_dev_lock > lock_sock > iso_conn_lock, which is how it is in connect/disconnect_cfm -> iso_conn_del -> iso_chan_del. Fix locking in iso_connect_cis/bis and sendmsg/recvmsg to take lock_sock around updating sk_state and conn. iso_conn_del must not occur during iso_connect_cis/bis, as it frees the iso_conn. Hold hdev->lock longer to prevent that. This should not reintroduce the issue fixed in commit 241f51931c35 ("Bluetooth: ISO: Avoid circular locking dependency"), since the we acquire locks in order. We retain the fix in iso_sock_connect to release lock_sock before iso_connect_* acquires hdev->lock. Similarly for commit 6a5ad251b7cd ("Bluetooth: ISO: Fix possible circular locking dependency"). We retain the fix in iso_conn_ready to not acquire iso_conn_lock before lock_sock. iso_conn_add shall return iso_conn with valid hcon. Make it so also when reusing an old CIS connection waiting for disconnect timeout (see __iso_sock_close where conn->hcon is set to NULL). Trace with iso_conn_del after iso_chan_add in iso_connect_cis: =============================================================== iso_sock_create:771: sock 00000000be9b69b7 iso_sock_init:693: sk 000000004dff667e iso_sock_bind:827: sk 000000004dff667e 70:1a:b8:98:ff:a2 type 1 iso_sock_setsockopt:1289: sk 000000004dff667e iso_sock_setsockopt:1289: sk 000000004dff667e iso_sock_setsockopt:1289: sk 000000004dff667e iso_sock_connect:875: sk 000000004dff667e iso_connect_cis:353: 70:1a:b8:98:ff:a2 -> 28:3d:c2:4a:7e:da hci_get_route:1199: 70:1a:b8:98:ff:a2 -> 28:3d:c2:4a:7e:da hci_conn_add:1005: hci0 dst 28:3d:c2:4a:7e:da iso_conn_add:140: hcon 000000007b65d182 conn 00000000daf8625e __iso_chan_add:214: conn 00000000daf8625e iso_connect_cfm:1700: hcon 000000007b65d182 bdaddr 28:3d:c2:4a:7e:da status 12 iso_conn_del:187: hcon 000000007b65d182 conn 00000000daf8625e, err 16 iso_sock_clear_timer:117: sock 000000004dff667e state 3 iso_chan_del:153: sk 000000004dff667e, conn 00000000daf8625e, err 16 hci_conn_del:1151: hci0 hcon 000000007b65d182 handle 65535 hci_conn_unlink:1102: hci0: hcon 000000007b65d182 hci_chan_list_flush:2780: hcon 000000007b65d182 iso_sock_getsockopt:1376: sk 000000004dff667e iso_sock_getname:1070: sock 00000000be9b69b7, sk 000000004dff667e iso_sock_getname:1070: sock 00000000be9b69b7, sk 000000004dff667e iso_sock_getsockopt:1376: sk 000000004dff667e iso_sock_getname:1070: sock 00000000be9b69b7, sk 000000004dff667e iso_sock_getname:1070: sock 00000000be9b69b7, sk 000000004dff667e iso_sock_shutdown:1434: sock 00000000be9b69b7, sk 000000004dff667e, how 1 __iso_sock_close:632: sk 000000004dff667e state 5 socket 00000000be9b69b7 BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 8000000006467067 P4D 8000000006467067 PUD 3f5f067 PMD 0 Oops: 0000 [#1] PREEMPT SMP PTI Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014 RIP: 0010:__iso_sock_close (net/bluetooth/iso.c:664) bluetooth =============================================================== Trace with iso_conn_del before iso_chan_add in iso_connect_cis: =============================================================== iso_connect_cis:356: 70:1a:b8:98:ff:a2 -> 28:3d:c2:4a:7e:da ... iso_conn_add:140: hcon 0000000093bc551f conn 00000000768ae504 hci_dev_put:1487: hci0 orig refcnt 21 hci_event_packet:7607: hci0: event 0x0e hci_cmd_complete_evt:4231: hci0: opcode 0x2062 hci_cc_le_set_cig_params:3846: hci0: status 0x07 hci_sent_cmd_data:3107: hci0 opcode 0x2062 iso_connect_cfm:1703: hcon 0000000093bc551f bdaddr 28:3d:c2:4a:7e:da status 7 iso_conn_del:187: hcon 0000000093bc551f conn 00000000768ae504, err 12 hci_conn_del:1151: hci0 hcon 0000000093bc551f handle 65535 hci_conn_unlink:1102: hci0: hcon 0000000093bc551f hci_chan_list_flush:2780: hcon 0000000093bc551f __iso_chan_add:214: conn 00000000768ae504 iso_sock_clear_timer:117: sock 0000000098323f95 state 3 general protection fault, probably for non-canonical address 0x30b29c630930aec8: 0000 [#1] PREEMPT SMP PTI CPU: 1 PID: 1920 Comm: bluetoothd Tainted: G E 6.3.0-rc7+ #4 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014 RIP: 0010:detach_if_pending+0x28/0xd0 Code: 90 90 0f 1f 44 00 00 48 8b 47 08 48 85 c0 0f 84 ad 00 00 00 55 89 d5 53 48 83 3f 00 48 89 fb 74 7d 66 90 48 8b 03 48 8b 53 08 <> RSP: 0018:ffffb90841a67d08 EFLAGS: 00010007 RAX: 0000000000000000 RBX: ffff9141bd5061b8 RCX: 0000000000000000 RDX: 30b29c630930aec8 RSI: ffff9141fdd21e80 RDI: ffff9141bd5061b8 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffb90841a67b88 R10: 0000000000000003 R11: ffffffff8613f558 R12: ffff9141fdd21e80 R13: 0000000000000000 R14: ffff9141b5976010 R15: ffff914185755338 FS: 00007f45768bd840(0000) GS:ffff9141fdd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000619000424074 CR3: 0000000009f5e005 CR4: 0000000000170ee0 Call Trace: timer_delete+0x48/0x80 try_to_grab_pending+0xdf/0x170 __cancel_work+0x37/0xb0 iso_connect_cis+0x141/0x400 [bluetooth] =============================================================== Trace with NULL conn->hcon in state BT_CONNECT: =============================================================== __iso_sock_close:619: sk 00000000f7c71fc5 state 1 socket 00000000d90c5fe5 ... __iso_sock_close:619: sk 00000000f7c71fc5 state 8 socket 00000000d90c5fe5 iso_chan_del:153: sk 00000000f7c71fc5, conn 0000000022c03a7e, err 104 ... iso_sock_connect:862: sk 00000000129b56c3 iso_connect_cis:348: 70:1a:b8:98:ff:a2 -> 28:3d:c2:4a:7d:2a hci_get_route:1199: 70:1a:b8:98:ff:a2 -> 28:3d:c2:4a:7d:2a hci_dev_hold:1495: hci0 orig refcnt 19 __iso_chan_add:214: conn 0000000022c03a7e iso_sock_clear_timer:117: sock 00000000129b56c3 state 3 ... iso_sock_ready:1485: sk 00000000129b56c3 ... iso_sock_sendmsg:1077: sock 00000000e5013966, sk 00000000129b56c3 BUG: kernel NULL pointer dereference, address: 00000000000006a8 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 1 PID: 1403 Comm: wireplumber Tainted: G E 6.3.0-rc7+ #4 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014 RIP: 0010:iso_sock_sendmsg+0x63/0x2a0 [bluetooth] =============================================================== Fixes: 241f51931c35 ("Bluetooth: ISO: Avoid circular locking dependency") Fixes: 6a5ad251b7cd ("Bluetooth: ISO: Fix possible circular locking dependency") Signed-off-by: Pauli Virtanen --- Notes: v2: no changes Don't have a clean reproducer, but these occur sometimes on bluetooth-next/master when sending data over ISO and disconnecting + reconnecting immediately, although the timing window required for these to occur is not so wide. These appear to be somewhat more easily reproduced if hci_le_set_cig_params is changed to return errors if CIG is busy. Enabling printks also seems to help. net/bluetooth/iso.c | 53 ++++++++++++++++++++++++++------------------- 1 file changed, 31 insertions(+), 22 deletions(-) diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c index b9a008fd10b1..8f570ab66ae7 100644 --- a/net/bluetooth/iso.c +++ b/net/bluetooth/iso.c @@ -123,8 +123,11 @@ static struct iso_conn *iso_conn_add(struct hci_conn *hcon) { struct iso_conn *conn = hcon->iso_data; - if (conn) + if (conn) { + if (!conn->hcon) + conn->hcon = hcon; return conn; + } conn = kzalloc(sizeof(*conn), GFP_KERNEL); if (!conn) @@ -311,14 +314,13 @@ static int iso_connect_bis(struct sock *sk) goto unlock; } - hci_dev_unlock(hdev); - hci_dev_put(hdev); + lock_sock(sk); err = iso_chan_add(conn, sk, NULL); - if (err) - return err; - - lock_sock(sk); + if (err) { + release_sock(sk); + goto unlock; + } /* Update source addr of the socket */ bacpy(&iso_pi(sk)->src, &hcon->src); @@ -335,7 +337,6 @@ static int iso_connect_bis(struct sock *sk) } release_sock(sk); - return err; unlock: hci_dev_unlock(hdev); @@ -403,14 +404,13 @@ static int iso_connect_cis(struct sock *sk) goto unlock; } - hci_dev_unlock(hdev); - hci_dev_put(hdev); + lock_sock(sk); err = iso_chan_add(conn, sk, NULL); - if (err) - return err; - - lock_sock(sk); + if (err) { + release_sock(sk); + goto unlock; + } /* Update source addr of the socket */ bacpy(&iso_pi(sk)->src, &hcon->src); @@ -427,7 +427,6 @@ static int iso_connect_cis(struct sock *sk) } release_sock(sk); - return err; unlock: hci_dev_unlock(hdev); @@ -1078,8 +1077,8 @@ static int iso_sock_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) { struct sock *sk = sock->sk; - struct iso_conn *conn = iso_pi(sk)->conn; struct sk_buff *skb, **frag; + size_t mtu; int err; BT_DBG("sock %p, sk %p", sock, sk); @@ -1091,11 +1090,18 @@ static int iso_sock_sendmsg(struct socket *sock, struct msghdr *msg, if (msg->msg_flags & MSG_OOB) return -EOPNOTSUPP; - if (sk->sk_state != BT_CONNECTED) + lock_sock(sk); + + if (sk->sk_state != BT_CONNECTED) { + release_sock(sk); return -ENOTCONN; + } + + mtu = iso_pi(sk)->conn->hcon->hdev->iso_mtu; + + release_sock(sk); - skb = bt_skb_sendmsg(sk, msg, len, conn->hcon->hdev->iso_mtu, - HCI_ISO_DATA_HDR_SIZE, 0); + skb = bt_skb_sendmsg(sk, msg, len, mtu, HCI_ISO_DATA_HDR_SIZE, 0); if (IS_ERR(skb)) return PTR_ERR(skb); @@ -1108,8 +1114,7 @@ static int iso_sock_sendmsg(struct socket *sock, struct msghdr *msg, while (len) { struct sk_buff *tmp; - tmp = bt_skb_sendmsg(sk, msg, len, conn->hcon->hdev->iso_mtu, - 0, 0); + tmp = bt_skb_sendmsg(sk, msg, len, mtu, 0, 0); if (IS_ERR(tmp)) { kfree_skb(skb); return PTR_ERR(tmp); @@ -1164,15 +1169,19 @@ static int iso_sock_recvmsg(struct socket *sock, struct msghdr *msg, BT_DBG("sk %p", sk); if (test_and_clear_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags)) { + lock_sock(sk); switch (sk->sk_state) { case BT_CONNECT2: - lock_sock(sk); iso_conn_defer_accept(pi->conn->hcon); sk->sk_state = BT_CONFIG; release_sock(sk); return 0; case BT_CONNECT: + release_sock(sk); return iso_connect_cis(sk); + default: + release_sock(sk); + break; } }