kernel/linux.git/net/bluetooth, branch v6.12.107

Bluetooth: ISO: do not force BT_LISTEN after a failed BIG sync

2026-08-27T12:32:08+00:00

commit 9838a80096ba472d5e03057136a112631aabae6e upstream. iso_sock_recvmsg() handles the deferred setup of a broadcast sink by dropping the socket lock, calling iso_conn_big_sync() and taking the lock again: release_sock(sk); iso_conn_big_sync(sk); lock_sock(sk); sk->sk_state = BT_LISTEN; The state is written unconditionally, but iso_conn_big_sync() returns void and has paths that do nothing at all: hci_get_route() may fail, and after re-acquiring the socket lock the connection may already be gone, in which case it bails out without ever issuing an LE BIG Create Sync. While the lock is dropped the connection can be torn down, for example when the controller reports HCI_EV_LE_PA_SYNC_LOST: hci_le_pa_sync_lost_evt() hci_disconn_cfm() -> iso_disconn_cfm() -> iso_conn_del() iso_chan_del() iso_pi(sk)->conn = NULL sk->sk_state = BT_CLOSED sock_set_flag(sk, SOCK_ZAPPED) iso_conn_big_sync() then finds conn == NULL and returns, but the caller still overwrites the BT_CLOSED that iso_chan_del() has just set. The socket ends up marked BT_LISTEN with no connection, so recvmsg() reports success for a setup that never happened and a later accept() waits for BIS connections that can never arrive instead of failing. A concurrent shutdown() reaches the same write by another route: __iso_sock_close() takes the BT_CONNECT2 PA sync path to iso_sock_disconn(), which sets BT_DISCONN but leaves conn and conn->hcon in place, so iso_conn_big_sync() succeeds and BT_LISTEN is written over BT_DISCONN. Both the BT_CONNECT2 and the BT_CONNECTED case write the state the same way. Let iso_conn_big_sync() report whether the BIG sync was started, and only move the socket to BT_LISTEN when it was and when the state has not changed while the lock was dropped, mirroring what the BT_CONNECT case of the same switch already does with iso_connect_cis(). Both conditions are needed, the error alone does not cover the shutdown() race. This corrupts the socket state machine only, it is not a memory safety issue. KASAN and lockdep stayed quiet in all of the runs below. Reproduced with an emulated controller over /dev/vhci on a KASAN + PROVE_LOCKING kernel. A PA sync broadcast sink socket is driven to BT_CONNECT2 and recvmsg() on it is raced against teardown, with a debug delay inside the lock-dropped section to widen the window: - HCI_EV_LE_PA_SYNC_LOST injected: 64 of 64 rounds left the socket in BT_LISTEN with the connection gone, recvmsg() returned 0 and accept() on that fd returned EAGAIN, which iso_sock_accept() can only do while the socket is BT_LISTEN. With this patch, 0 of 64, recvmsg() returns an error and accept() returns EBADFD. - shutdown() instead of a controller event: 24 of 32 rounds wedged in BT_LISTEN, 0 of 32 with this patch. With only the error check in place and a short window, one round still wedged while recvmsg() returned 0, which is the case the state re-check covers. An unraced control round behaves the same before and after: recvmsg() returns 0, the socket reaches BT_LISTEN and an LE BIG Create Sync is issued. Fixes: 7a17308c1788 ("Bluetooth: iso: Fix circular lock in iso_conn_big_sync") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: hci_event: validate LE Set CIG Parameters response

2026-08-27T12:32:08+00:00

commit 0acd4eeb4b225b9bebbf9ef96cc10cdd79b94899 upstream. The Command Complete dispatch validates only the fixed part of the LE Set CIG Parameters response. After that part is pulled from the skb, hci_cc_le_set_cig_params() trusts num_handles and reads each entry in the trailing handle array. Matching num_handles against the command's num_cis does not guarantee that the response contains the advertised handles. A truncated response from a malfunctioning controller can therefore make the handler read beyond the skb data. Validate that the remaining skb data contains all advertised handles. Include this in the existing response validation so malformed responses also follow the established CIG failure handling. Fixes: 26afbd826ee3 ("Bluetooth: Add initial implementation of CIS connections") Cc: stable@vger.kernel.org Signed-off-by: Laxman Acharya Padhya Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: hci_event: fix LE list UAF on reset

2026-08-27T12:32:08+00:00

commit 33af47e847fe4a28b109673affb5874015d54f5a upstream. hci_cc_reset() clears the LE accept and resolving lists without taking hdev->lock. Other command-complete handlers serialize updates to these lists with that lock, and the debugfs readers hold it while walking them. This permits the reset completion and a debugfs read to interleave as follows: hci_rx_work debugfs reader ----------- -------------- lock hdev->lock fetch current entry list_del(entry) kfree(entry) read entry fields The reader then dereferences a freed list entry and may follow its stale next pointer. KASAN reported: BUG: KASAN: slab-use-after-free in white_list_show+0x15f/0x180 Read of size 1 at addr ffff8881015dab16 by task poc/95 Call Trace: white_list_show+0x15f/0x180 seq_read_iter+0x3ff/0x1190 seq_read+0x267/0x3d0 vfs_read+0x177/0xa20 ksys_read+0xf7/0x1c0 Allocated by task 91: hci_bdaddr_list_add+0x1a6/0x3a0 hci_cc_le_add_to_accept_list+0xab/0x140 hci_cmd_complete_evt+0x26c/0x9a0 hci_event_packet+0x454/0xb20 hci_rx_work+0x293/0x730 Freed by task 90: kfree+0x131/0x3c0 hci_bdaddr_list_clear+0xd8/0x160 hci_cc_reset+0x28a/0x370 hci_cmd_complete_evt+0x26c/0x9a0 hci_event_packet+0x454/0xb20 hci_rx_work+0x293/0x730 Take hdev->lock around both list clears. This matches the existing mutation and traversal locking convention. Fixes: a4d5504d5c39 ("Bluetooth: Clear LE white list when resetting controller") Fixes: cfdb0c2d095a ("Bluetooth: Store Resolv list size") Cc: stable@vger.kernel.org Signed-off-by: Chengfeng Ye Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: RFCOMM: take rfcomm_mutex for the deferred setup accept

2026-08-27T12:32:03+00:00

commit 43a556b2fd43f2df6dded59c2e26560a27874c24 upstream. rfcomm_sock_recvmsg() completes a deferred setup by calling rfcomm_dlc_accept() without holding any RFCOMM lock: if (test_and_clear_bit(RFCOMM_DEFER_SETUP, &d->flags)) { rfcomm_dlc_accept(d); return 0; } and rfcomm_dlc_accept() dereferences the session on its first line: struct sock *sk = d->session->sock->sk; Every other path that touches d->session runs under rfcomm_mutex: rfcomm_dlc_open(), rfcomm_dlc_close(), rfcomm_dlc_exists(), rfcomm_dlc_send_rpn(), and the RFCOMM thread through rfcomm_process_sessions(). rfcomm_connect_ind() is even documented as "called under rfcomm_lock()". This call site is the only one that skips it. The RFCOMM_DEFER_SETUP bit looks like it serialises the accept against teardown, since __rfcomm_dlc_close() returns early when it wins the test_and_clear. But rfcomm_recv_disc() forces the state first: d->state = BT_CLOSED; __rfcomm_dlc_close(d, err); and the early return only covers BT_CONNECT, BT_CONFIG, BT_OPEN and BT_CONNECT2. With the state already BT_CLOSED that switch does not match, the bit is never consulted, and __rfcomm_dlc_close() falls through to rfcomm_dlc_unlink(), which sets d->session = NULL. So a remote DISC on a deferred dlc clears the session while leaving RFCOMM_DEFER_SETUP set. The next recvmsg() then passes the test_and_clear and dereferences a NULL session. No timing window is needed: once the DISC has been processed, the dereference is unconditional. Give rfcomm_dlc_accept() the same shape as rfcomm_dlc_open() and rfcomm_dlc_close(): an exported wrapper that takes rfcomm_mutex and re-checks the session, around a __rfcomm_dlc_accept() that the two in-core callers, which already hold the mutex, keep using. Reproduced on a KASAN + PROVE_LOCKING kernel with a BR/EDR peer emulated over /dev/vhci: the peer brings up an ACL link, opens L2CAP on the RFCOMM PSM, starts a session, opens a dlc on a channel bound with BT_DEFER_SETUP, and sends DISC after the socket is accepted. recv() on the accepted socket then hits: Oops: general protection fault KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] RIP: 0010:rfcomm_dlc_accept+0x54/0x350 Call Trace: rfcomm_sock_recvmsg+0x1cd/0x230 sock_recvmsg+0x166/0x1c0 __sys_recvfrom+0x20d/0x300 0x10 is the offset of sock in struct rfcomm_session. With this patch the same run completes with recv() returning 0 and no report, and lockdep stays quiet, confirming rfcomm_mutex is still taken before lock_sock on this path as it is on the thread side. Fixes: bb23c0ab8246 ("Bluetooth: Add support for deferring RFCOMM connection setup") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: ISO: fix CONNECTED -> CLOSED transition on shutdown/release

2026-08-09T18:23:22+00:00

commit 0786469ee242952008628ed0e2d386098e2065ab upstream. Commit d57e506f6a1e ("Bluetooth: ISO: clear iso_data always when detaching conn from hcon") merged a version of the UAF fix that breaks releasing connected ISO sockets. Since hci_conn::iso_data is set to NULL, iso_chan_del() won't be called when the hci_conn disconnects, and the ISO socket does not emit POLLHUP correctly. Fix by retaining full hci_conn <-> iso_conn association while in BT_DISCONNECT state, so that local disconnect via shutdown() follows similar ISO socket code path as remote disconnect. Use a separate flag to track whether hci_conn_drop() is needed, instead of setting iso_conn::hcon = NULL In iso_sock_ready(), disallow disconnecting socket going BT_CONNECTED, in case hcon connects while its drop is pending. Fixes: d57e506f6a1e ("Bluetooth: ISO: clear iso_data always when detaching conn from hcon") Fixes: fbdc4bc47268 ("Bluetooth: ISO: Use defer setup to separate PA sync and BIG sync") Signed-off-by: Pauli Virtanen Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: HIDP: validate numbered report payloads

2026-08-09T18:23:12+00:00

commit 34f53d27b81a16a02828c8fdfa4e02badc326f17 upstream. When hidp_get_raw_report() waits for a numbered report, hidp_process_data() compares the expected report number with skb->data[0]. A connected HIDP peer can reply with only a DATA transaction header, leaving the skb empty after the header is removed. KMSAN reports an uninitialized-value use in hidp_session_run(), with the value originating in __alloc_skb() through vhci_write(). The transaction header checks remove the empty-frame reports, but this report remains until the payload check is added. The comparison can also consume a peer-controlled byte beyond the declared L2CAP PDU. A DATA | FEATURE response followed by an extra 0x01 byte made the current code accept that byte as report ID 1 and complete HIDIOCGFEATURE with a zero-byte result. With this change the malformed response is rejected with -EIO, while a subsequent valid response still succeeds. Require a payload byte before comparing a numbered report ID. Unnumbered reports continue to accept an empty payload. Fixes: 0ff1731a1ae5 ("HID: bt: Add support for hidraw HIDIOCGFEATURE and HIDIOCSFEATURE") Cc: stable@vger.kernel.org Signed-off-by: Sangho Lee Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: HIDP: reject frames without a transaction header

2026-08-09T18:23:12+00:00

commit 47778d2c2087b5d192398f6fddf692d16a5431cf upstream. hidp_recv_ctrl_frame() and hidp_recv_intr_frame() read skb->data[0] before checking that the L2CAP SDU contains a transaction header. A connected HIDP peer can send an empty basic-mode SDU and make both paths use an uninitialized byte from skb tailroom. KMSAN reports the use in hidp_session_run(), with the uninitialized value originating in __alloc_skb() through vhci_write(). The control path produces two reports and the interrupt path produces one. The byte can also be controlled by a malformed lower-layer packet. If an HCI ACL packet contains an L2CAP PDU with a declared zero-length payload followed by an extra 0x15 byte, l2cap_recv_acldata() reduces skb->len to the declared PDU length before dispatch. The current HIDP path nevertheless consumes the extra byte as HIDP_TRANS_HID_CONTROL | HIDP_CTRL_VIRTUAL_CABLE_UNPLUG and terminates the HIDP session. With this change, the same packet is discarded and a subsequent feature report request succeeds. Pull the transaction header with skb_pull_data() and discard frames that do not contain it. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Sangho Lee Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: hci_sync: Fix advertising data UAFs

2026-08-09T18:23:12+00:00

commit cdc36db204ffd97b947d64374cf23a210dc74777 upstream. hci_find_adv_instance() returns an adv_info pointer that is valid only while hdev->lock is held. The advertising command-sync paths perform instance lookups without that lock and, in some cases, retain the pointer while waiting for a controller response. An advertising termination event can therefore interleave as follows: hci_cmd_sync_work hci_rx_work hci_find_adv_instance() __hci_cmd_sync_status() wait for controller reply hci_dev_lock() hci_remove_adv_instance() kfree(adv) adv->scan_rsp_changed = false KASAN reported: BUG: KASAN: slab-use-after-free in hci_set_ext_scan_rsp_data_sync+0x2e1/0x300 Write of size 1 at addr ffff88810a45d21d by task kworker/u17:0/88 Workqueue: hci0 hci_cmd_sync_work Call Trace: hci_set_ext_scan_rsp_data_sync+0x2e1/0x300 hci_schedule_adv_instance_sync+0x390/0x4c0 hci_cmd_sync_work+0x173/0x300 Allocated by task 87: hci_add_adv_instance+0x538/0xac0 add_advertising+0x885/0x1160 Freed by task 89: kfree+0x131/0x3c0 hci_remove_adv_instance+0x1d8/0x3b0 hci_le_ext_adv_term_evt+0x17b/0x730 Protect the instance lookup and payload construction in the extended advertising, scan response, and periodic advertising data paths. Snapshot the advertising parameters under hdev->lock, but release the lock before waiting for the controller. Clear advertising-data dirty bits before issuing their commands and restore them after a failure using a fresh lookup. Likewise, update the reported transmit power through a fresh lookup after the parameter command completes. No adv_info pointer then survives an HCI command wait. Fixes: cba6b758711c ("Bluetooth: hci_sync: Make use of hci_cmd_sync_queue set 2") Cc: stable@vger.kernel.org Suggested-by: Luiz Augusto von Dentz Signed-off-by: Chengfeng Ye Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: mgmt: fix UAF in pair command cancellation

2026-08-09T18:23:12+00:00

commit d0a7b48ad0921bd88effaee10bf970ab1d5d0ddd upstream. The pairing completion and authentication failure callbacks look up the pending MGMT_OP_PAIR_DEVICE command by walking hdev->mgmt_pending. The lookup returned a command that was still linked on the shared pending list, without keeping mgmt_pending_lock held for the later dereference and removal. A concurrent MGMT_OP_CANCEL_PAIR_DEVICE request can remove and free the same pending command before the callback uses it. The reverse race is also possible when cancel_pair_device() gets a command from pending_find() and a callback removes it before the cancel path dereferences it. This can lead to a use-after-free and a second list_del(). Make the pairing lookup helpers transfer ownership of the pending command by removing it from hdev->mgmt_pending while holding mgmt_pending_lock. The callbacks and cancel path then complete the command and free it directly, so racing paths cannot find or free the same command again. Take a temporary hci_conn reference in cancel_pair_device() because the command completion drops the reference stored in the pending command. Fixes: e9a416b5ce0c ("Bluetooth: Add mgmt_pair_device command") Cc: stable@vger.kernel.org Reported-by: Vega Assisted-by: Codex:gpt-5.4 Signed-off-by: Zihan Xi Reviewed-by: Ren Wei Reported-by: Vega Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: mgmt: fix pending command UAF in EIR updates

2026-08-09T18:23:12+00:00

commit 8f2f62855a41d1730fb9e8122912bd2c8d6bed5d upstream. MGMT_OP_SET_LOCAL_NAME is handled asynchronously on powered controllers and can run set_name_sync(). When the controller is BR/EDR capable, set_name_sync() updates the local name and then rebuilds EIR data through eir_create(). The EIR builder walks hdev->uuids, but the UUID list can be changed and entries can be freed by MGMT_OP_ADD_UUID and MGMT_OP_REMOVE_UUID. pending_eir_or_class() is meant to serialize management commands that can change EIR or the class of device, but it did not include MGMT_OP_SET_LOCAL_NAME. In addition, it walked hdev->mgmt_pending without hdev->mgmt_pending_lock even though pending commands are added and removed under that mutex. A racing command completion can therefore remove and free a pending command while pending_eir_or_class() is still inspecting it, leading to a use-after-free in the pending-command list or allowing a local name update to rebuild EIR while UUID entries are being removed. Take hdev->mgmt_pending_lock while scanning hdev->mgmt_pending and treat MGMT_OP_SET_LOCAL_NAME as an EIR/class-affecting pending command on the powered asynchronous path. Check for a conflicting pending command before copying the new short name so a rejected SET_LOCAL_NAME request does not modify hdev->short_name. Fixes: 6fe26f694c82 ("Bluetooth: MGMT: Protect mgmt_pending list with its own lock") Cc: stable@vger.kernel.org Reported-by: Vega Assisted-by: Codex:gpt-5.4 Signed-off-by: Zihan Xi Signed-off-by: Ren Wei Reported-by: Vega Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman