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 60AC130D3F6; Thu, 16 Jul 2026 14:06:16 +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=1784210781; cv=none; b=TMnwKIAa/ePS8l+rotPW6mlTE29seHWEdV305DPdqLHCe7SugCFnIYNcTiRTlZomEkTKySL0hTYAP78Hj/ErMV6/aYs3WgAWQH6mc7wbYTTQ32b41L9QKxF//AjiAcW0u2aYYhZe2Xk4wAuqdgtABChsxxfLSp8dgzCzof2/U84= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784210781; c=relaxed/simple; bh=S9KSm71HcWXofqLTMGRj8FBNwZjaxveRaruXr4rZSxs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=B4AQTEeEpjHcGuMktr9ugUOq16nBHTln4VqOJwASdeMl2K35MrslwJqwZpEk/IqRNOndOXnLdBcu8xu6INQMAm5s9gvBTN4Zer2viJdrJma4y7OFh6NRr0L+HZaivq2jsl/vdszqdNBC3O0TWl5voKED49hRKCaWFIFMSCFWTnE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fv3O0Vor; 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="fv3O0Vor" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C6E841F000E9; Thu, 16 Jul 2026 14:06:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784210776; bh=POsWuDtwKFw2o8ezmLJM2mxmfckrlZe51K9orDihMC4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=fv3O0Voru7KeBHVdBs4Wbu3JVczGShfM1mOB6FZs5dowQzN7xoBGfLD7HwEZ/v969 edYT7sQ4QW4yRNAG3CDD+sYmfgpWFUzhVWgPLFR+I1igv4pt4d0No116R7CiwJ/vaM hBsqZGpqwcJTWCQljDTfwSUTWs5DWIh8MO46gs2c= 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 6.18 175/480] Bluetooth: MGMT: Fix UAF of hci_conn_params in add_device_complete Date: Thu, 16 Jul 2026 15:28:42 +0200 Message-ID: <20260716133048.499230104@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260716133044.672218725@linuxfoundation.org> References: <20260716133044.672218725@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 6.18-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 @@ -7641,6 +7641,8 @@ 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)); @@ -7649,6 +7651,7 @@ 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,