linux-next.git/net/bluetooth, branch master

Bluetooth: mgmt: Translate HCI reason in Device Disconnected event

2026-07-10T20:08:14+00:00

MGMT_EV_DEVICE_DISCONNECTED carries a reason field which is defined to be one of MGMT_DEV_DISCONN_* (0x00..0x05). hci_disconn_complete_evt() converts the HCI error with hci_to_mgmt_reason(), but two other paths pass the raw HCI error straight through: hci_cs_disconnect() -> cp->reason mgmt_connect_failed() -> status The latter is reached whenever the adapter is powered off or suspended: hci_disconnect_all_sync() aborts every link with HCI_ERROR_REMOTE_POWER_OFF, hci_disconnect_sync() deliberately does not wait for HCI_EV_DISCONN_COMPLETE for that reason, so that hci_abort_conn_sync() finishes the connection off through hci_conn_failed() instead. As a result userspace sees an out of range reason: @ MGMT Event: Device Disconnected (0x000c) plen 8 BR/EDR Address: 8C:A9:6F:2C:51:46 Reason: Reserved (0x15) bluetoothd: btd_bearer_disconnected() Unknown disconnection value: 21 bluetoothd: device_disconnected() Unknown disconnection value: 21 Export hci_to_mgmt_reason() and use it in both places, so that a power off is reported as MGMT_DEV_DISCONN_REMOTE rather than as the raw HCI_ERROR_REMOTE_POWER_OFF (0x15). Fixes: d47da6bd4cfa ("Bluetooth: hci_core: Fix sending MGMT_EV_CONNECT_FAILED") Fixes: 182ee45da083 ("Bluetooth: hci_sync: Rework hci_suspend_notifier") Signed-off-by: Mikhail Gavrilov Signed-off-by: Luiz Augusto von Dentz

Bluetooth: hci_sync: hold hdev->lock for hci_conn_params lookups

2026-07-10T19:58:06+00:00

hci_conn_params_lookup requires hdev->lock be held, otherwise the list iteration or param access is not safe. Hold hdev->lock for params lookups in hci_sync. Fixes: c530569adc19 ("Bluetooth: hci_core: Introduce HCI_CONN_FLAG_PAST") Signed-off-by: Pauli Virtanen Signed-off-by: Luiz Augusto von Dentz

Bluetooth: mgmt: hold reference for hci_conn in mgmt_pending_cmds

2026-07-10T19:57:42+00:00

Dereferencing RCU-protected pointers outside critical sections is invalid and may lead to UAF. Use of hci_conn in hci_sync callbacks also needs to hold refcount to avoid UAF. Take appropriate locks for hci_conn lookups, and take refcount for hci_conn pointers stored in mgmt_pending_cmd so that the pointer stays valid. When accessing conn->state, ensure hdev->lock is held to avoid data race. Fixes: 7b445e220db9 ("Bluetooth: MGMT: Fix holding hci_conn reference while command is queued") Signed-off-by: Pauli Virtanen Signed-off-by: Luiz Augusto von Dentz

Bluetooth: mgmt: fix locking in unpair_device/disconnect_sync

2026-07-10T19:55:33+00:00

Dereferencing RCU-protected pointers outside critical sections is invalid and may lead to UAF. Take hdev->lock for hci_conn lookup and hci_abort_conn(). Don't use RCU to ensure the conn is fully initialized at this point. Fixes: 227a0cdf4a028 ("Bluetooth: MGMT: Fix not generating command complete for MGMT_OP_DISCONNECT") Signed-off-by: Pauli Virtanen Signed-off-by: Luiz Augusto von Dentz

Bluetooth: hci_sync: extend conn_hash lookup critical sections

2026-07-10T19:54:25+00:00

Using RCU-protected pointers outside the critical sections without refcount is incorrect and may result to UAF. Extend critical section to cover both hci_conn_hash lookup and use of the returned conn. Add surrounding rcu_read_lock() also when return value is not used, in preparation for RCU lockdep requirement to hci_lookup_le_connect(). This avoids concurrent deletion of the conn before we are done dereferencing it. Also, make sure to hold hdev->lock when accessing hdev->accept_list. Fixes: 6d0417e4e1cf ("Bluetooth: hci_conn: Fix not setting conn_timeout for Broadcast Receiver") Signed-off-by: Pauli Virtanen Signed-off-by: Luiz Augusto von Dentz

Bluetooth: coredump: Do not export hci_devcd_rx() and hci_devcd_timeout()

2026-07-10T19:52:33+00:00

Do not export both functions since they are only used internally within the bluetooth module. Signed-off-by: Zijun Hu Signed-off-by: Luiz Augusto von Dentz

Bluetooth: MGMT: revalidate LOAD_CONN_PARAM queued update

2026-07-07T15:52:44+00:00

MGMT_OP_LOAD_CONN_PARAM queues conn_update_sync() when a single parameter update changes an existing LE central connection. The queued work currently stores a borrowed hci_conn_params entry from hdev->le_conn_params. A later LOAD_CONN_PARAM request can clear disabled parameters and free that entry before hci_cmd_sync_work() runs the queued callback. Do not keep the borrowed hci_conn_params pointer in queued work. Queue the hci_conn instead and hold a reference until the queued callback completes. When the work runs, revalidate that the connection is still present, look up the current hci_conn_params entry, and cancel the update if userspace removed that entry while the work was pending. Copy the interval values from the current params entry under hdev->lock, then drop the lock and keep using hci_le_conn_update_sync() to issue the update. Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in conn_update_sync+0x2a/0xf0 [bluetooth] Read of size 1 at addr ffff88810c697126 by task kworker/u17:0/377 Workqueue: hci0 hci_cmd_sync_work [bluetooth] Call Trace: dump_stack_lvl+0x66/0xa0 print_report+0xce/0x5f0 kasan_report+0xe0/0x110 conn_update_sync+0x2a/0xf0 [bluetooth] hci_cmd_sync_work+0x187/0x210 [bluetooth] process_one_work+0x4fd/0xbc0 worker_thread+0x2d8/0x570 kthread+0x1ad/0x1f0 ret_from_fork+0x3c9/0x540 ret_from_fork_asm+0x1a/0x30 Allocated by task 466: hci_conn_params_add+0xa6/0x240 [bluetooth] load_conn_param+0x4e1/0x850 [bluetooth] hci_sock_sendmsg+0x96b/0xf80 [bluetooth] Freed by task 474: kfree+0x313/0x590 hci_conn_params_clear_disabled+0x9b/0xc0 [bluetooth] load_conn_param+0x4bf/0x850 [bluetooth] hci_sock_sendmsg+0x96b/0xf80 [bluetooth] Fixes: 0ece498c27d8c ("Bluetooth: MGMT: Make MGMT_OP_LOAD_CONN_PARAM update existing connection") Suggested-by: Luiz Augusto von Dentz Assisted-by: Codex:gpt-5.5 Signed-off-by: Cen Zhang Signed-off-by: Luiz Augusto von Dentz

Bluetooth: L2CAP: fix tx ident leak for commands without a response

2026-07-02T17:24:28+00:00

Commit 6c3ea155e5ee ("Bluetooth: L2CAP: Fix not tracking outstanding TX ident") changed ident allocation to use an IDA, releasing idents in l2cap_put_ident() when the matching response command is received. But identifiers allocated for commands that have no response defined are never released. In particular L2CAP_LE_CREDITS is sent repeatedly for the lifetime of an LE CoC channel, so a peer streaming data to the host exhausts the 1-255 ident range after 254 credit packets. From then on l2cap_get_ident() fails: kernel: Bluetooth: Unable to allocate ident: -28 and every subsequent L2CAP_LE_CREDITS packet is sent with ident 0, which is invalid (Core Spec, Vol 3, Part A, Section 4: "Signaling identifier 0x00 is an invalid identifier and shall never be used in any command"). Remote stacks that validate the ident drop these commands, never receive new credits, and the channel stalls permanently. With default socket buffers this happens after roughly 0.5 MB of received data (the exact amount depends on the socket receive buffer): < ACL Data TX: Handle 2048 flags 0x00 dlen 12 LE L2CAP: LE Flow Control Credit (0x16) ident 0 len 4 Source CID: 64 Credits: 1 Release the ident immediately after sending L2CAP_LE_CREDITS since no response will ever release it. Use a local variable instead of chan->ident so that an ident that an EXT_FLOWCTL channel may be waiting on (e.g. a pending reconfigure) is not overwritten by a credit packet. Also add the missing L2CAP_LE_CONN_RSP case to l2cap_put_ident() so idents allocated for outgoing L2CAP_LE_CONN_REQ commands are released when the response arrives. Fixes: 6c3ea155e5ee ("Bluetooth: L2CAP: Fix not tracking outstanding TX ident") Link: https://bugzilla.kernel.org/show_bug.cgi?id=221629 Assisted-by: Claude:claude-opus-4.8 Assisted-by: Fable:5 Signed-off-by: Stig Hornang Signed-off-by: Luiz Augusto von Dentz

Bluetooth: ISO: fix malformed ISO_END/CONT handling

2026-07-02T16:07:38+00:00

Core specification (Part C vol 4 sec 5.4.5) does not exclude empty ISO_CONT, ISO_END packets. We currently reject them if they are last. If controller sends malformed sequence ISO_START -> rx_len = 4, ISO_CONT skb->len 4, ISO_START that ends payload in ISO_CONT, we leak conn->rx_skb. If controller sends too long ISO_END, we panic on skb_put. If controller sends too short ISO_END we accept it. Fix by marking unfinished ISO_START via conn->rx_skb != NULL. Check skb->len properly before skb_put. Combine the ISO_CONT/END code paths as they require the same initial checks. Reject too short ISO_END packets. Fixes: 84c24fb151fc ("Bluetooth: ISO: drop ISO_END frames received without prior ISO_START") Fixes: ccf74f2390d6 ("Bluetooth: Add BTPROTO_ISO socket type") Signed-off-by: Pauli Virtanen Signed-off-by: Luiz Augusto von Dentz

Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb()

2026-06-29T19:12:25+00:00

l2cap_sock_new_connection_cb() returned l2cap_pi(sk)->chan after release_sock(parent). Once the parent lock is dropped the newly enqueued child socket sk is reachable via the accept queue, so another task can accept and free it before the callback dereferences sk, resulting in a use-after-free. Rework the ->new_connection() op so the core, rather than the callback, owns the child channel's lifetime. The op now receives a pre-allocated new_chan and returns an errno instead of allocating and returning a channel. l2cap_new_connection() allocates the child channel and links it into the conn list via __l2cap_chan_add() before invoking the callback, so the conn-list reference keeps the channel alive once release_sock(parent) exposes the socket to other tasks. Channel configuration that was duplicated in l2cap_sock_init() and the various new_connection callbacks is consolidated into l2cap_chan_set_defaults(), which now inherits from the parent channel when one is supplied. Fixes: 8ffb929098a5 ("Bluetooth: Remove parent socket usage from l2cap_core.c") Cc: stable@kernel.org Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Siwei Zhang Signed-off-by: Luiz Augusto von Dentz