From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2713742CAF6; Thu, 16 Jul 2026 14:25:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784211925; cv=none; b=AVPaxitwAI4eUZKTtoQYHr8Z7NZgLIdJQWeTwPaHFo+Ty6MMtM90SoXgqkrsgTcEKX1pYuKvXCN8bqe6WQ/9KehGLdsEJByXAHrqHH5U1boxc1quyiNfILNdFKfDQ7iJoxDsa+e0KlCTAcEda1TLFkVjou3AFpLG6J9bJ1eQIyU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784211925; c=relaxed/simple; bh=EHlmoCxgzP5u+63Uykp+SMWKrmLWGFhrO6a9GugkLTU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rIJTHt2sD96dyXW7THJcOQv0URvXX0IS/Pjil+wUjOxAUfdnO+/9hkbelqm+8x2kgPxyBn+x7mkHr/5Jn1u1Aq5BlUDeJ5CL6U6QOWvZvSqsSV5xqJVdjtlqZnazDwT8YHNkoh1xIeDUzvfMqsnTcwoVWA6FOVFyQN3GP+NsPhk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=aT41A2iL; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="aT41A2iL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 801EE1F00A3E; Thu, 16 Jul 2026 14:25:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784211924; bh=/+y2kALPM1ttrbFM2DeLMlfQnSiKB/bMa8AlcCt9Dvg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=aT41A2iL13WozUX118EOR7sgnu20g3RM2wMg95oLq5DCHZd7Kxjg1DPmOnmy7qeU2 dDS1albDcnQkoaZKyMaXR98qd3p8F0ytbgh62YhdblI3gNf3/85HSXPHB+XKB7nTCu rG/sGkshRO/f2Bl1Sb8plTU3farwZ/aVDR+1/sBE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Samuel Page , Luiz Augusto von Dentz Subject: [PATCH 6.12 131/349] Bluetooth: MGMT: Fix UAF of hci_conn_params in add_device_complete Date: Thu, 16 Jul 2026 15:31:05 +0200 Message-ID: <20260716133036.294902614@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260716133033.287196923@linuxfoundation.org> References: <20260716133033.287196923@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Samuel Page commit fa85d985f614bc3feb343000f14a1072e99b0df1 upstream. add_device_complete() runs from the hci_cmd_sync_work kworker, which holds only hci_req_sync_lock and *not* hci_dev_lock. It calls hci_conn_params_lookup() and then dereferences the returned object (params->flags) without taking hci_dev_lock: params = hci_conn_params_lookup(hdev, &cp->addr.bdaddr, le_addr_type(cp->addr.type)); ... device_flags_changed(NULL, hdev, &cp->addr.bdaddr, cp->addr.type, hdev->conn_flags, params ? params->flags : 0); hci_conn_params_lookup() walks hdev->le_conn_params and is documented to require hdev->lock. A concurrent MGMT_OP_REMOVE_DEVICE (remove_device()), which does run under hci_dev_lock, can call hci_conn_params_free() to list_del() and kfree() the very object the lookup returned, so the subsequent params->flags read touches freed memory [0]. Hold hci_dev_lock() across the hci_conn_params_lookup() and the read of params->flags (and the matching event emission) so the lookup result cannot be freed by a concurrent remove_device() before it is used, honouring the locking contract of hci_conn_params_lookup(). [0]: (trailing page/memory-state dump trimmed) BUG: KASAN: slab-use-after-free in add_device_complete+0x358/0x3d8 net/bluetooth/mgmt.c:7671 Read of size 1 at addr ffff000017ab26c1 by task kworker/u9:8/388 CPU: 1 UID: 0 PID: 388 Comm: kworker/u9:8 Not tainted 7.0.11 #20 PREEMPT Hardware name: linux,dummy-virt (DT) Workqueue: hci0 hci_cmd_sync_work Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xb4/0xd4 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x118/0x5d8 mm/kasan/report.c:482 kasan_report+0xb0/0xf4 mm/kasan/report.c:595 __asan_report_load1_noabort+0x20/0x2c mm/kasan/report_generic.c:378 add_device_complete+0x358/0x3d8 net/bluetooth/mgmt.c:7671 hci_cmd_sync_work+0x14c/0x240 net/bluetooth/hci_sync.c:334 process_one_work+0x628/0xd38 kernel/workqueue.c:3289 process_scheduled_works kernel/workqueue.c:3372 [inline] worker_thread+0x7a8/0xac0 kernel/workqueue.c:3453 kthread+0x39c/0x444 kernel/kthread.c:436 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 Allocated by task 3401: kasan_save_stack+0x3c/0x64 mm/kasan/common.c:57 kasan_save_track+0x20/0x3c mm/kasan/common.c:78 kasan_save_alloc_info+0x40/0x54 mm/kasan/generic.c:570 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xd4/0xd8 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x1b0/0x458 mm/slub.c:5385 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] hci_conn_params_add+0x10c/0x4b0 net/bluetooth/hci_core.c:2279 hci_conn_params_set net/bluetooth/mgmt.c:5162 [inline] add_device+0x5b4/0xa54 net/bluetooth/mgmt.c:7755 hci_mgmt_cmd net/bluetooth/hci_sock.c:1721 [inline] hci_sock_sendmsg+0x10b4/0x1dd0 net/bluetooth/hci_sock.c:1841 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0xe0/0x128 net/socket.c:742 sock_write_iter+0x250/0x390 net/socket.c:1195 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x66c/0xab0 fs/read_write.c:688 ksys_write+0x1fc/0x24c fs/read_write.c:740 __do_sys_write fs/read_write.c:751 [inline] __se_sys_write fs/read_write.c:748 [inline] __arm64_sys_write+0x70/0xa4 fs/read_write.c:748 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x84/0x2a8 arch/arm64/kernel/syscall.c:49 el0_svc_common.constprop.0+0xe4/0x294 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x44/0x5c arch/arm64/kernel/syscall.c:151 el0_svc+0x38/0xac arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0xa0/0xe4 arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 Freed by task 3740: kasan_save_stack+0x3c/0x64 mm/kasan/common.c:57 kasan_save_track+0x20/0x3c mm/kasan/common.c:78 kasan_save_free_info+0x4c/0x74 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x88/0xb8 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2685 [inline] slab_free mm/slub.c:6170 [inline] kfree+0x14c/0x458 mm/slub.c:6488 hci_conn_params_free+0x288/0x484 net/bluetooth/hci_core.c:2312 remove_device+0x4b0/0x968 net/bluetooth/mgmt.c:7919 hci_mgmt_cmd net/bluetooth/hci_sock.c:1721 [inline] hci_sock_sendmsg+0x10b4/0x1dd0 net/bluetooth/hci_sock.c:1841 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0xe0/0x128 net/socket.c:742 sock_write_iter+0x250/0x390 net/socket.c:1195 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x66c/0xab0 fs/read_write.c:688 ksys_write+0x1fc/0x24c fs/read_write.c:740 __do_sys_write fs/read_write.c:751 [inline] __se_sys_write fs/read_write.c:748 [inline] __arm64_sys_write+0x70/0xa4 fs/read_write.c:748 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x84/0x2a8 arch/arm64/kernel/syscall.c:49 el0_svc_common.constprop.0+0xe4/0x294 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x44/0x5c arch/arm64/kernel/syscall.c:151 el0_svc+0x38/0xac arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0xa0/0xe4 arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 Fixes: 1e2e3044c1bc ("Bluetooth: MGMT: Fix MGMT_OP_ADD_DEVICE invalid device flags") Cc: stable@vger.kernel.org Assisted-by: Bynario AI Signed-off-by: Samuel Page Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman --- net/bluetooth/mgmt.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -7740,6 +7740,8 @@ static void add_device_complete(struct h if (!err) { struct hci_conn_params *params; + hci_dev_lock(hdev); + params = hci_conn_params_lookup(hdev, &cp->addr.bdaddr, le_addr_type(cp->addr.type)); @@ -7748,6 +7750,7 @@ static void add_device_complete(struct h device_flags_changed(NULL, hdev, &cp->addr.bdaddr, cp->addr.type, hdev->conn_flags, params ? params->flags : 0); + hci_dev_unlock(hdev); } mgmt_cmd_complete(cmd->sk, hdev->id, MGMT_OP_ADD_DEVICE,