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5 daysBluetooth: RFCOMM: Fix session UAF in set_termiosChengfeng Ye2-4/+20
commit c783399efc22d035443f1dfbf2a09bf9562aaa5e upstream. rfcomm_tty_set_termios() tests dlc->session without rfcomm_mutex and later passes the pointer to rfcomm_send_rpn(). The latter dereferences both session->initiator and session->sock. Meanwhile, krfcommd can unlink the DLC and free the session while holding rfcomm_mutex. The race can proceed as follows: TTY ioctl task krfcommd -------------- -------- load dlc->session enter rfcomm_send_rpn() lock rfcomm_mutex clear dlc->session free session unlock rfcomm_mutex read session->initiator KASAN reported: BUG: KASAN: slab-use-after-free in rfcomm_send_rpn+0x297/0x2a0 Read of size 4 at addr ffff88810012a850 by task poc/92 Call Trace: rfcomm_send_rpn+0x297/0x2a0 rfcomm_tty_set_termios+0x50d/0x850 tty_set_termios+0x596/0x950 set_termios+0x46a/0x6e0 tty_mode_ioctl+0x152/0xbd0 tty_ioctl+0x915/0x1240 __x64_sys_ioctl+0x134/0x1c0 Allocated by task 92: rfcomm_session_add+0x9e/0x2e0 rfcomm_dlc_open+0x8b1/0xe00 rfcomm_dev_activate+0x85/0x1a0 rfcomm_tty_open+0x90/0x280 Freed by task 68: kfree+0x131/0x3c0 rfcomm_session_del+0x119/0x180 rfcomm_run+0x737/0x4710 Add rfcomm_dlc_send_rpn(), which holds rfcomm_mutex while it verifies that the DLC is still attached and sends the RPN frame. Have the TTY path use the helper and drop its unlocked session check. This keeps the session valid through both the frame construction and socket send. Fixes: 3a5e903c09ae ("[Bluetooth]: Implement RFCOMM remote port negotiation") Cc: stable@vger.kernel.org Signed-off-by: Chengfeng Ye <nicoyip.dev@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 daysBluetooth: hci_sync: Protect UUID list traversalChengfeng Ye1-2/+11
commit e9027ffbf5a0f3c12ca8900822e884eae9f0821b upstream. The hci_sync conversion moved class-of-device and EIR generation from an HCI request built under hdev->lock to asynchronous command sync work. The worker holds hdev->req_lock, but that lock does not serialize access to hdev->uuids against add_uuid() and remove_uuid(), which update the list under hdev->lock. The following interleaving can therefore occur: CPU0 (command sync work) CPU1 (management socket) fetch uuid from the list list_del(&uuid->list) kfree(uuid) read uuid->size KASAN reports the resulting use-after-free: BUG: KASAN: slab-use-after-free in eir_create+0xb8f/0xee0 Read of size 1 at addr ffff88810dbd8620 by task kworker/u17:0/87 Workqueue: hci0 hci_cmd_sync_work Call Trace: eir_create+0xb8f/0xee0 hci_update_eir_sync+0x1c0/0x330 hci_cmd_sync_work+0x13c/0x290 process_one_work+0x63a/0x1070 worker_thread+0x45b/0xd10 Allocated by task 86: __kasan_kmalloc+0x8f/0xa0 add_uuid+0x18a/0x4b0 hci_sock_sendmsg+0x1033/0x1ea0 Freed by task 92: __kasan_slab_free+0x43/0x70 kfree+0x131/0x3c0 remove_uuid+0x25e/0x560 hci_sock_sendmsg+0x1033/0x1ea0 Hold hdev->lock while generating and committing the class-of-device and EIR snapshots. Release it before sending an HCI command, so controller waits do not happen under the device lock. This protects all UUID list walks in these paths and restores the serialization lost in the command sync conversion. Fixes: 161510ccf91c ("Bluetooth: hci_sync: Make use of hci_cmd_sync_queue set 1") Cc: stable@vger.kernel.org Signed-off-by: Chengfeng Ye <nicoyip.dev@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 daysBluetooth: mgmt: Translate HCI reason in Device Disconnected eventMikhail Gavrilov2-18/+19
[ Upstream commit c1cec2bbbeb5922d42d28c6af1707c4f3f8647e3 ] 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 <mikhail.v.gavrilov@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
5 daysBluetooth: hci_sync: hold hdev->lock for hci_conn_params lookupsPauli Virtanen1-4/+20
[ Upstream commit c363202ec841df36421ec280eea3d5f94f556143 ] 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 <pav@iki.fi> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
5 daysBluetooth: mgmt: hold reference for hci_conn in mgmt_pending_cmdsPauli Virtanen1-4/+22
[ Upstream commit da55f570191d5d72f10c607a7043b947eb05ea46 ] 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 <pav@iki.fi> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
5 daysBluetooth: mgmt: fix locking in unpair_device/disconnect_syncPauli Virtanen1-0/+16
[ Upstream commit 16cd66443957e4ad42155c6fec401012f600c6f8 ] 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 <pav@iki.fi> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
5 daysBluetooth: hci_sync: extend conn_hash lookup critical sectionsPauli Virtanen1-3/+39
[ Upstream commit d5efd6e4b8b0634af6843178fe1a7dd2b2178a3d ] 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 <pav@iki.fi> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
5 daysBluetooth: MGMT: revalidate LOAD_CONN_PARAM queued updateCen Zhang1-9/+35
[ Upstream commit 2bf282f8f715f5d05d6f4c49ffb3bd241c5e667e ] 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: <TASK> 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 <luiz.dentz@gmail.com> Assisted-by: Codex:gpt-5.5 Signed-off-by: Cen Zhang <zzzccc427@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-07-24Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb()Siwei Zhang4-105/+121
[ Upstream commit 6fef032af0092ed5ccb767239a9ac1bc38c08a40 ] 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 <oss@fourdim.xyz> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-24Bluetooth: 6lowpan: fix cyclic locking warning on netdev unregisterPauli Virtanen1-2/+23
[ Upstream commit 9707a015fe8f3ba8ec7c270f3b2b8efb38823d6b ] 6lowpan.c has theoretically conflicting lock orderings, which lockdep complains about: a) rtnl_lock > hdev->workqueue from 6lowpan.c:delete_netdev -> rtnl_lock -> device_del -> put_device(parent) -> hci_release_dev -> destroy_workqueue b) hdev->workqueue > l2cap_conn->lock > chan->lock > rtnl_lock from hci_rx_work -> 6lowpan.c:chan_ready_cb -> lowpan_register_netdev, ifup -> rtnl_lock Actual deadlock appears not possible, as hci_rx_work is disabled and l2cap_conn flushed already on hdev unregister. Hence, do minimal thing to make lockdep happy by breaking chain a) by holding hdev refcount until after netdev put in 6lowpan.c. Fixes the lockdep complaint: WARNING: possible circular locking dependency detected. kworker/0:1/11 is trying to acquire lock: ffff8880023b3940 ((wq_completion)hci0#2){+.+.}-{0:0}, at: touch_wq_lockdep_map+0x8b/0x130 but task is already holding lock: ffffffff95e4f9c0 (rtnl_mutex){+.+.}-{4:4}, at: lowpan_unregister_netdev+0xd/0x30 Workqueue: events delete_netdev Signed-off-by: Pauli Virtanen <pav@iki.fi> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Stable-dep-of: 6fef032af009 ("Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb()") Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-24Bluetooth: L2CAP: fix tx ident leak for commands without a responseStig Hornang1-2/+13
[ Upstream commit 6e1930ece855a4c256f1c7e6632d634cfb9888b5 ] 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 <stig@hornang.me> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-07-24Bluetooth: ISO: fix malformed ISO_END/CONT handlingPauli Virtanen1-15/+16
[ Upstream commit e054c1a6ae7310d2815778fddb87da616e11c255 ] 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 <pav@iki.fi> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-07-24Bluetooth: sco: Fix a race condition in sco_sock_timeout()Sungwoo Kim1-1/+14
[ Upstream commit 0f8a5dcc66648b6e1458a9f3ba4c5a0463a228fc ] sco_sock_timeout() runs asynchronously and lock_sock(sk). If the socket is closing while the timer is running, it holds the same lock (lock_sock(sk)) twice, leading to a deadlock. CPU 0 CPU 1 ==================== ====================== sco_sock_close() sco_sock_timeout() lock_sock(sk) // <-- LOCK __sco_sock_close() sco_chan_del() sco_conn_put() sco_conn_free() disable_delayed_work_sync() lock(sk) // <-- SAME LOCK Fix this by moving disable_delayed_work_sync() outside of lock_sock(sk), ensuring that no lock_sock(sk) is held before sco_sock_timeout(). Lockdep splat: WARNING: possible circular locking dependency detected 6.13.0-rc4 #7 Not tainted syz-executor292/9514 is trying to acquire lock: ffff8881115d5070 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire sect/v6.13-rc4/./include/linux/rcupdate.h:337 [inline] ffff8881115d5070 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}, at: rcu_read_lock sect/v6.13-rc4/./include/linux/rcupdate.h:849 [inline] ffff8881115d5070 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}, at: start_flush_work sect/v6.13-rc4/kernel/workqueue.c:4137 [inline] ffff8881115d5070 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}, at: __flush_work+0xd1/0xc40 sect/v6.13-rc4/kernel/workqueue.c:4195 but task is already holding lock: ffff88807db3a258 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: lock_sock sect/v6.13-rc4/./include/net/sock.h:1623 [inline] ffff88807db3a258 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_sock_close+0x25/0x100 sect/v6.13-rc4/net/bluetooth/sco.c:524 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}: lock_acquire+0x1c4/0x520 sect/v6.13-rc4/kernel/locking/lockdep.c:5849 lock_sock_nested+0x48/0x130 sect/v6.13-rc4/net/core/sock.c:3622 lock_sock sect/v6.13-rc4/./include/net/sock.h:1623 [inline] sco_sock_timeout+0xbe/0x270 sect/v6.13-rc4/net/bluetooth/sco.c:158 process_one_work sect/v6.13-rc4/kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa99/0x18f0 sect/v6.13-rc4/kernel/workqueue.c:3310 worker_thread+0x8a9/0xd80 sect/v6.13-rc4/kernel/workqueue.c:3391 kthread+0x2c6/0x360 sect/v6.13-rc4/kernel/kthread.c:389 ret_from_fork+0x4e/0x80 sect/v6.13-rc4/arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 sect/v6.13-rc4/arch/x86/entry/entry_64.S:244 -> #0 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}: check_prev_add sect/v6.13-rc4/kernel/locking/lockdep.c:3161 [inline] check_prevs_add sect/v6.13-rc4/kernel/locking/lockdep.c:3280 [inline] validate_chain+0x1888/0x5760 sect/v6.13-rc4/kernel/locking/lockdep.c:3904 __lock_acquire+0x13b4/0x2120 sect/v6.13-rc4/kernel/locking/lockdep.c:5226 lock_acquire+0x1c4/0x520 sect/v6.13-rc4/kernel/locking/lockdep.c:5849 touch_work_lockdep_map sect/v6.13-rc4/kernel/workqueue.c:3909 [inline] start_flush_work sect/v6.13-rc4/kernel/workqueue.c:4163 [inline] __flush_work+0x70f/0xc40 sect/v6.13-rc4/kernel/workqueue.c:4195 __cancel_work_sync sect/v6.13-rc4/kernel/workqueue.c:4351 [inline] disable_delayed_work_sync+0xbb/0xf0 sect/v6.13-rc4/kernel/workqueue.c:4514 sco_conn_free sect/v6.13-rc4/net/bluetooth/sco.c:95 [inline] kref_put sect/v6.13-rc4/./include/linux/kref.h:65 [inline] sco_conn_put+0x18f/0x270 sect/v6.13-rc4/net/bluetooth/sco.c:107 sco_chan_del+0xe2/0x210 sect/v6.13-rc4/net/bluetooth/sco.c:236 sco_sock_close+0x8f/0x100 sect/v6.13-rc4/net/bluetooth/sco.c:526 sco_sock_release+0x62/0x2d0 sect/v6.13-rc4/net/bluetooth/sco.c:1300 __sock_release+0xe1/0x2d0 sect/v6.13-rc4/net/socket.c:640 sock_close+0x1c/0x30 sect/v6.13-rc4/net/socket.c:1408 __fput+0x2bd/0xa80 sect/v6.13-rc4/fs/file_table.c:450 __fput_sync+0x15e/0x1c0 sect/v6.13-rc4/fs/file_table.c:535 __do_sys_close sect/v6.13-rc4/fs/open.c:1554 [inline] __se_sys_close sect/v6.13-rc4/fs/open.c:1539 [inline] __x64_sys_close+0x93/0x120 sect/v6.13-rc4/fs/open.c:1539 do_syscall_x64 sect/v6.13-rc4/arch/x86/entry/common.c:52 [inline] do_syscall_64+0xee/0x210 sect/v6.13-rc4/arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: e6720779ae61 ("Bluetooth: SCO: Use kref to track lifetime of sco_conn") Acked-by: Dave Tian <daveti@purdue.edu> Signed-off-by: Sungwoo Kim <iam@sung-woo.kim> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-07-24Bluetooth: MGMT: Fix adv monitor add failure cleanupCen Zhang2-1/+3
[ Upstream commit 384a4b2fef9ffe5e270ee5558975c0504881c5fb ] hci_add_adv_monitor() publishes a new adv_monitor in hdev->adv_monitors_idr before the powered MSFT setup step. The MSFT offload add path can then fail either locally before the controller add command completes, or in the MSFT add callback. In the current queued management add flow, hci_cmd_sync_work() still invokes mgmt_add_adv_patterns_monitor_complete() with the original pending command after msft_add_monitor_pattern() returns. The buggy scenario involves two paths, with each column showing the order within that path: MSFT add handling MGMT completion 1. insert monitor and handle 1. receive sync error 2. send MSFT add command 2. call add-monitor completion 3. callback sees bad response 3. load cmd->user_data 4. callback frees monitor 4. read monitor->handle Local MSFT setup failures have the other half of the same ownership bug: they return an error after the IDR insertion, but no later code removes the failed monitor from the IDR. Keep ownership with the pending management command until its completion. For normal management adds, the MSFT add callback now records successful controller state and returns errors to its caller. The management completion frees the monitor on non-success after copying the response handle, while resume/reregister callback-error cleanup remains in the MSFT callback. The success path keeps the existing bookkeeping. Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth] Call Trace: <TASK> dump_stack_lvl+0x66/0xa0 print_report+0xce/0x5f0 ? mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth] ? srso_alias_return_thunk+0x5/0xfbef5 ? __virt_addr_valid+0x19f/0x330 ? mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth] kasan_report+0xe0/0x110 ? mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth] mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth] ? srso_alias_return_thunk+0x5/0xfbef5 ? 0xffffffffc00d00da ? __pfx_mgmt_add_adv_patterns_monitor_complete+0x10/0x10 [bluetooth] ? __pfx_mgmt_add_adv_patterns_monitor_complete+0x10/0x10 [bluetooth] ? hci_cmd_sync_work+0x1ab/0x210 [bluetooth] hci_cmd_sync_work+0x1c0/0x210 [bluetooth] ? __pfx_mgmt_add_adv_patterns_monitor_complete+0x10/0x10 [bluetooth] process_one_work+0x4fd/0xbc0 ? __pfx_process_one_work+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? __list_add_valid_or_report+0x37/0xf0 ? __pfx_hci_cmd_sync_work+0x10/0x10 [bluetooth] ? srso_alias_return_thunk+0x5/0xfbef5 worker_thread+0x2d8/0x570 ? __pfx_worker_thread+0x10/0x10 kthread+0x1ad/0x1f0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x3c9/0x540 ? __pfx_ret_from_fork+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? __switch_to+0x2e9/0x730 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Allocated by task 471 on cpu 3 at 285.205389s: kasan_save_stack+0x33/0x60 kasan_save_track+0x17/0x60 __kasan_kmalloc+0xaa/0xb0 add_adv_patterns_monitor_rssi+0xd5/0x230 [bluetooth] hci_sock_sendmsg+0x96b/0xf80 [bluetooth] __sys_sendto+0x2bc/0x2d0 __x64_sys_sendto+0x76/0x90 do_syscall_64+0x115/0x6a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 454 on cpu 2 at 285.217112s: kasan_save_stack+0x33/0x60 kasan_save_track+0x17/0x60 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x5f/0x80 kfree+0x313/0x590 msft_add_monitor_sync+0x54a/0x570 [bluetooth] hci_add_adv_monitor+0x133/0x180 [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 Fixes: a2a4dedf88ab ("Bluetooth: advmon offload MSFT add monitor") Assisted-by: Codex:gpt-5.5 Signed-off-by: Cen Zhang <zzzccc427@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-07-24Bluetooth: 6lowpan: hold L2CAP conn across debugfs controlCen Zhang2-6/+16
[ Upstream commit 518aa9505fa10ea5662349e5d2efd8c9e32a820b ] get_l2cap_conn() looks up an LE hci_conn under hdev protection, but then drops that protection before reading hcon->l2cap_data and before lowpan_control_write() later dereferences conn->hcon. A disconnect or device close can tear down the same L2CAP connection in that window. The buggy scenario involves two paths, with each column showing the order within that path: 6LoWPAN control write: HCI disconnect/device close: 1. get_l2cap_conn() finds hcon 1. hci_disconn_cfm() dispatches and hcon->l2cap_data. the L2CAP disconnect callback. 2. get_l2cap_conn() drops hdev 2. l2cap_conn_del() clears protection and returns conn. hcon->l2cap_data and drops the L2CAP connection reference. 3. lowpan_control_write() reads 3. hci_conn_del() removes and drops conn->hcon. the HCI connection. Take a reference to the L2CAP connection with l2cap_conn_hold_unless_zero() while hdev is still locked, and drop that reference after the debugfs command's last use of conn. This mirrors the existing L2CAP ACL receive-side handoff and keeps the connection dereferenceable after leaving hdev protection. Export the existing helper so the bluetooth_6lowpan module can use the same lifetime primitive. Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in lowpan_control_write+0x374/0x520 The buggy address belongs to the object at ffff888111b9d000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 0 bytes inside of freed 1024-byte region [ffff888111b9d000, ffff888111b9d400) Read of size 8 Call trace: dump_stack_lvl+0x66/0xa0 print_report+0xce/0x5f0 lowpan_control_write+0x374/0x520 (net/bluetooth/6lowpan.c:1131) srso_alias_return_thunk+0x5/0xfbef5 __virt_addr_valid+0x19f/0x330 kasan_report+0xe0/0x110 __debugfs_file_get+0xf7/0x400 full_proxy_write+0x9e/0xd0 vfs_write+0x1b0/0x810 ksys_write+0xd2/0x170 dnotify_flush+0x32/0x220 do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87) entry_SYSCALL_64_after_hwframe+0x77/0x7f Allocated by task stack: kasan_save_stack+0x33/0x60 kasan_save_track+0x17/0x60 __kasan_kmalloc+0xaa/0xb0 l2cap_conn_add+0x45/0x520 l2cap_chan_connect+0xac6/0xd90 l2cap_sock_connect+0x216/0x350 __sys_connect+0x101/0x130 __x64_sys_connect+0x40/0x50 do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87) entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task stack: kasan_save_stack+0x33/0x60 kasan_save_track+0x17/0x60 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x5f/0x80 kfree+0x313/0x590 hci_conn_hash_flush+0xc0/0x140 hci_dev_close_sync+0x41a/0xb00 hci_dev_close+0x12f/0x160 hci_sock_ioctl+0x157/0x570 sock_do_ioctl+0xf7/0x210 sock_ioctl+0x32f/0x490 __x64_sys_ioctl+0xc7/0x110 do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87) entry_SYSCALL_64_after_hwframe+0x77/0x7f kasan_record_aux_stack+0xa7/0xc0 insert_work+0x32/0x100 __queue_work+0x262/0xa60 queue_work_on+0xad/0xb0 l2cap_connect_cfm+0x4ef/0x670 hci_le_remote_feat_complete_evt+0x247/0x430 hci_event_packet+0x360/0x6f0 hci_rx_work+0x2ae/0x7a0 process_one_work+0x4fd/0xbc0 worker_thread+0x2d8/0x570 kthread+0x1ad/0x1f0 ret_from_fork+0x3c9/0x540 ret_from_fork_asm+0x1a/0x30 Fixes: 6b8d4a6a0314 ("Bluetooth: 6LoWPAN: Use connected oriented channel instead of fixed one") Assisted-by: Codex:gpt-5.5 Signed-off-by: Cen Zhang <zzzccc427@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-07-24Bluetooth: 6lowpan: avoid untracked enable workCen Zhang1-23/+4
[ Upstream commit 352a59dc1f4a41314b6f827c17e16af7ca88271a ] lowpan_enable_set() allocates a temporary work item and schedules do_enable_set() on system_wq, then returns to debugfs. The debugfs active operation has ended at that point, but the worker still executes module text and manipulates enable_6lowpan and listen_chan. bt_6lowpan_exit() removes the debugfs files and immediately closes and puts listen_chan. It has no pointer to the queued work item, so it cannot cancel or flush it before tearing down the state that the worker uses. The buggy scenario involves two paths, with each column showing the order within that path: debugfs enable write module exit 1. lowpan_enable_set() allocates 1. bt_6lowpan_exit() removes set_enable work the debugfs file 2. schedule_work() queues 2. bt_6lowpan_exit() closes do_enable_set() and puts listen_chan 3. the write operation returns 3. module teardown can continue 4. do_enable_set() later runs against stale state Run the enable state transition synchronously in lowpan_enable_set() instead. The simple debugfs setter can sleep, and this file already handles the 6LoWPAN control write synchronously under the same set_lock. Once the setter returns, debugfs removal covers the whole operation and exit can no longer race with an untracked work item. Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in do_enable_set+0x113/0x2e0 Workqueue: events do_enable_set [bluetooth_6lowpan] The buggy address belongs to the object at ffff888109cb8000 Fixes: 90305829635d ("Bluetooth: 6lowpan: Converting rwlocks to use RCU") Assisted-by: Codex:gpt-5.5 Signed-off-by: Cen Zhang <zzzccc427@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-07-24Bluetooth: hci: validate codec capability element lengthSamuel Moelius1-1/+1
[ Upstream commit c38fbcdc407925c7088f7e5f11c1fff73d2d35a2 ] Read Local Codec Capabilities returns a sequence of capability elements. Each element starts with a one-byte length followed by that many payload bytes. hci_read_codec_capabilities() checks that the skb contains the length byte, but then validates only caps->len against the remaining skb length. A malformed controller response with one remaining byte and caps->len set to one passes that check even though the element needs two bytes. The parser then records a two-byte capability and copies one byte beyond the advertised response payload into the codec list. Validate the full element size, including the length byte, before adding it to the accumulated capability length. This preserves all well-formed capability elements and drops only truncated controller responses. Fixes: 8961987f3f5f ("Bluetooth: Enumerate local supported codec and cache details") Assisted-by: Codex:gpt-5.5-cyber-preview Signed-off-by: Samuel Moelius <sam.moelius@trailofbits.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-07-24Bluetooth: hci_core: Fix UAF in hci_unregister_dev()Jordan Walters1-0/+2
[ Upstream commit 5edcc018fa6e80b2c478454a4a8229c23d67c181 ] hci_unregister_dev() does not disable cmd_timer and ncmd_timer before the hci_dev structure is freed. If a timeout fires during device teardown, the callback dereferences freed memory (including the hdev->reset function pointer), leading to a use-after-free. Add disable_delayed_work_sync() calls alongside the existing disable_work_sync() calls to ensure both timers are fully quiesced before teardown proceeds. Fixes: 0d151a103775 ("Bluetooth: hci_core: cancel all works upon hci_unregister_dev()") Signed-off-by: Jordan Walters <jaggyaur@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-07-24Bluetooth: hci_event: fix simultaneous discovery stuck in FINDINGJiajia Liu1-0/+7
[ Upstream commit 96d006ae6445679436b945593950fd465eba7e76 ] When hci_inquiry_complete_evt is called between le_scan_disable and le_set_scan_enable_complete and no remote name needs to be resolved, the interleaved discovery with SIMULTANEOUS quirk gets stuck in DISCOVERY_FINDING. le_set_scan_enable_complete does not check inquiry state. No one sets DISCOVERY_STOPPED in this process. Add state check in le_set_scan_enable_complete and change state if the state is DISCOVERY_FINDING. Tested with AX201 (8087:0026) in Dell Vostro 13. Discovering disabled MGMT Event below is reported when running into the above condition. @ MGMT Command: Start Discovery (0x0023) {0x0001} [hci0] 10885.970873 Address type: 0x07 BR/EDR LE Public LE Random ... < HCI Command: LE Set Extended Scan Enable #38205 [hci0] 10886.131438 Extended scan: Enabled (0x01) Filter duplicates: Enabled (0x01) Duration: 0 msec (0x0000) Period: 0.00 sec (0x0000) > HCI Event: Command Complete (0x0e) plen 4 #38206 [hci0] 10886.133295 LE Set Extended Scan Enable (0x08|0x0042) ncmd 2 Status: Success (0x00) @ MGMT Event: Discovering (0x0013) plen 2 {0x0001} [hci0] 10886.133414 Address type: 0x07 BR/EDR LE Public LE Random Discovery: Enabled (0x01) < HCI Command: Inquiry (0x01|0x0001) plen 5 #38207 [hci0] 10886.133528 Access code: 0x9e8b33 (General Inquiry) Length: 10.24s (0x08) Num responses: 0 > HCI Event: Command Status (0x0f) plen 4 #38208 [hci0] 10886.141333 Inquiry (0x01|0x0001) ncmd 2 Status: Success (0x00) ... < HCI Command: LE Set Extended Scan Enable #38242 [hci0] 10896.381802 Extended scan: Disabled (0x00) Filter duplicates: Disabled (0x00) Duration: 0 msec (0x0000) Period: 0.00 sec (0x0000) > HCI Event: Inquiry Complete (0x01) plen 1 #38243 [hci0] 10896.383419 Status: Success (0x00) > HCI Event: Command Complete (0x0e) plen 4 #38244 [hci0] 10896.394378 LE Set Extended Scan Enable (0x08|0x0042) ncmd 2 Status: Success (0x00) @ MGMT Event: Device Found (0x0012) plen 22 {0x0001} [hci0] 10896.394497 LE Address: 88:12:AC:92:43:69 RSSI: -101 dBm (0x9b) Flags: 0x00000004 Not Connectable Data length: 8 Company: Xiaomi Inc. (911) Data[0]: 16-bit Service UUIDs (complete): 1 entry Xiaomi Inc. (0xfdaa) @ MGMT Event: Discovering (0x0013) plen 2 {0x0001} [hci0] 10896.394506 Address type: 0x07 BR/EDR LE Public LE Random Discovery: Disabled (0x00) Fixes: 8ffde2a73f2c ("Bluetooth: Convert le_scan_disable timeout to hci_sync") Signed-off-by: Jiajia Liu <liujiajia@kylinos.cn> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-07-24Bluetooth: eir: Fix stack OOB write when prepending the Flags ADWeiming Shi1-3/+5
[ Upstream commit 6f5fb689fdf80bdd143f22a502f9eb1f3c85e286 ] eir_create_adv_data() builds the advertising data into a fixed-size buffer ("size", 31 for the legacy path). It may prepend a 3-byte "Flags" AD structure (LE_AD_NO_BREDR on an LE-only controller) and then copies the per-instance data without checking that it still fits: memcpy(ptr, adv->adv_data, adv->adv_data_len); tlv_data_max_len() only reserves those 3 bytes when the user-supplied flags carry a managed-flags bit, so an instance added with flags == 0 is accepted with adv_data_len up to the full buffer. At advertise time the flags are still prepended, and the memcpy() writes 3 + adv_data_len bytes into the size-byte buffer: BUG: KASAN: stack-out-of-bounds in eir_create_adv_data (net/bluetooth/eir.c:301) Write of size 31 at addr ffff88800a547bdc by task kworker/u9:0/65 Workqueue: hci0 hci_cmd_sync_work __asan_memcpy (mm/kasan/shadow.c:106) eir_create_adv_data (net/bluetooth/eir.c:301) hci_update_adv_data_sync (net/bluetooth/hci_sync.c:1310) hci_schedule_adv_instance_sync (net/bluetooth/hci_sync.c:1817) hci_cmd_sync_work (net/bluetooth/hci_sync.c:332) This frame has 1 object: [32, 64) 'cp' The "Flags" structure is added by the kernel, not requested by userspace, so only prepend it when it fits together with the instance advertising data; when there is no room for both, drop the flags rather than the user-provided data. Reachable by a local user with CAP_NET_ADMIN owning an LE-only controller on the legacy advertising path. Fixes: b44133ff03be ("Bluetooth: Support the "discoverable" adv flag") Reported-by: Xiang Mei <xmei5@asu.edu> Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Weiming Shi <bestswngs@gmail.com> Reported-by: Xiang Mei <xmei5@asu.edu> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-07-18Bluetooth: 6lowpan: Fix using chan->conn as indication to no remote netdevLuiz Augusto von Dentz1-15/+3
commit d38eaf611839b85ade3dd3db309dbc8aaaaf0095 upstream. b66774b48dd9 ("Bluetooth: L2CAP: Fix UAF in channel timeout by holding conn ref") don't reset the chan->conn to NULL anymore making the bt# netdev not be remove once the last l2cap_chan_del is removed. Instead of restoring the original behavior this remove the logic of keeping the interface after the last channel is removed because it never worked as intended and the l2cap_chan_del always detach its l2cap_conn which results in always removing the channel anyway. Fixes: b66774b48dd9 ("Bluetooth: L2CAP: Fix UAF in channel timeout by holding conn ref") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-18Bluetooth: L2CAP: validate option length before reading conf opt valueMuhammad Bilal1-8/+28
commit 687617555cedfb74c9e3cb85d759b908dcb17856 upstream. l2cap_get_conf_opt() derives the option length from the attacker-controlled opt->len field and immediately dereferences opt->val (as u8, get_unaligned_le16() or get_unaligned_le32(), or a raw pointer for the default case) before any caller has confirmed that opt->len bytes are present in the buffer. The callers (l2cap_parse_conf_req(), l2cap_parse_conf_rsp() and l2cap_conf_rfc_get()) only detect a malformed option afterwards, once the running length has gone negative, by which point the out-of-bounds read has already executed. An existing post-hoc length check keeps the garbage value from being consumed, so this is not a data leak in the current control flow. It is still a validate-after-use ordering bug: up to 4 bytes are read past the end of the buffer before it is known to contain them, and it is fragile to future changes in the callers. Fix it at the source. Pass the end of the buffer into l2cap_get_conf_opt() and refuse to touch opt->val unless the full option (header + value) fits. Each caller computes an end pointer once before the loop and checks the return value directly instead of inferring the error from a negative length. Fixes: 7c9cbd0b5e38 ("Bluetooth: Verify that l2cap_get_conf_opt provides large enough buffer") Cc: stable@vger.kernel.org Signed-off-by: Muhammad Bilal <meatuni001@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-18Bluetooth: L2CAP: cancel pending_rx_work before taking conn->lockRunyu Xiao1-8/+2
commit 2641a9e0a1dd4af2e21995470a21d55dd35e5203 upstream. l2cap_conn_del() takes conn->lock and then calls cancel_work_sync() for pending_rx_work. process_pending_rx() takes the same mutex, so teardown can deadlock against the worker it is flushing. This issue was found by our static analysis tool and then manually reviewed against the current tree. The grounded PoC kept the l2cap_conn_ready() -> queue_work(..., &conn->pending_rx_work) submit path, the l2cap_conn_del() -> cancel_work_sync(&conn->pending_rx_work) teardown path, and the process_pending_rx() -> mutex_lock(&conn->lock) worker edge. Lockdep reported: WARNING: possible circular locking dependency detected process_pending_rx+0x21/0x2a [vuln_msv] l2cap_conn_del.constprop.0+0x3f/0x4e [vuln_msv] *** DEADLOCK *** Cancel pending_rx_work before taking conn->lock, matching the existing lock-before-drain ordering used for the two delayed works in the same teardown path. The pending_rx queue is still purged after the work has been cancelled and conn->lock has been acquired. Fixes: 7ab56c3a6ecc ("Bluetooth: Fix deadlock in l2cap_conn_del()") Cc: stable@vger.kernel.org Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-18Bluetooth: ISO: avoid NULL deref of conn in iso_conn_big_sync()Muhammad Bilal1-1/+12
commit d5541eb148da72d5e0a1bca8ecd171f9fc8b366f upstream. iso_conn_big_sync() drops the socket lock to call hci_get_route() and then re-acquires it, but dereferences iso_pi(sk)->conn->hcon afterwards without re-checking that conn is still valid. While the lock is dropped, the connection can be torn down under the same socket lock: iso_disconn_cfm() -> iso_conn_del() -> iso_chan_del() sets iso_pi(sk)->conn to NULL (and the broadcast teardown path can also clear conn->hcon on its own). When iso_conn_big_sync() re-acquires the lock and reads conn->hcon, conn may be NULL, causing a NULL pointer dereference (hcon is the first member of struct iso_conn). This path is reached from iso_sock_recvmsg() for a PA-sync broadcast sink socket (BT_SK_DEFER_SETUP | BT_SK_PA_SYNC), so the dropped-lock window can race with connection teardown driven by controller events. Re-validate iso_pi(sk)->conn and its hcon after re-acquiring the socket lock and bail out if the connection went away, as already done in the sibling iso_sock_rebind_bc(). Fixes: 7a17308c17880d ("Bluetooth: iso: Fix circular lock in iso_conn_big_sync") Cc: stable@vger.kernel.org Signed-off-by: Muhammad Bilal <meatuni001@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-18Bluetooth: hci_conn: Fix null ptr deref in hci_abort_conn()Siwei Zhang2-32/+122
commit 12917f591cea1af36087dba5b9ec888652f0b42a upstream. hci_abort_conn() read hci_skb_event(hdev->sent_cmd) when a connection was pending, but hdev->sent_cmd can be NULL while req_status is still HCI_REQ_PEND, leading to a NULL pointer dereference and a general protection fault from the hci_rx_work() receive path. Instead of inspecting hdev->sent_cmd, track the in-flight create connection command with a new per-connection HCI_CONN_CREATE flag and route all cancellation through hci_cancel_connect_sync(), which dispatches to a dedicated per-type cancel function. The create command is in exactly one of two states: still queued, or in flight. The cancel function holds cmd_sync_work_lock across the whole decision: the worker takes this lock to dequeue every entry, so while it is held a queued command cannot start running and an in-flight command cannot complete and let the next command become pending. This keeps the flag test and hci_cmd_sync_cancel() atomic with respect to the worker, so a queued command is simply dequeued, and an in-flight command owned by this connection is cancelled without the risk of cancelling an unrelated command that became pending in the meantime. CIS uses the same flag mechanism via HCI_CONN_CREATE_CIS but cannot be dequeued per-connection. hci_acl_create_conn_sync() and hci_le_create_conn_sync() clear HCI_CONN_CREATE after the create command completes, but the command status handler can free conn via hci_conn_del() (for example when the controller rejects the connection) while the worker is still blocked on the connection complete event. Hold a reference on conn across the create command so the flag can be cleared without a use-after-free. Fixes: a13f316e90fd ("Bluetooth: hci_conn: Consolidate code for aborting connections") Cc: stable@vger.kernel.org Suggested-by: XIAO WU <xiaowu.417@qq.com> Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Siwei Zhang <oss@fourdim.xyz> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-18Bluetooth: fix UAF in bt_accept_dequeue()Yousef Alhouseen2-16/+5
commit 4bd0b274054f2679f28b70222b607bb0afc3ab9a upstream. bt_accept_get() takes a temporary reference before dropping the accept queue lock. bt_accept_dequeue() currently drops that reference before bt_accept_unlink(), leaving only the queue reference. bt_accept_unlink() drops the queue reference. The subsequent sock_hold() therefore accesses freed memory if it was the final reference, as observed by KASAN during listening L2CAP socket cleanup. Retain the temporary queue-walk reference through unlink and hand it to the caller on success. Drop it explicitly on the closed and not-yet-connected paths. Fixes: ab1513597c6c ("Bluetooth: fix UAF in l2cap_sock_cleanup_listen() vs l2cap_conn_del()") Reported-by: syzbot+674ff7e4d7fdfd572afc@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=674ff7e4d7fdfd572afc Cc: stable@vger.kernel.org Signed-off-by: Yousef Alhouseen <alhouseenyousef@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-18Bluetooth: bnep: pin L2CAP connection during netdev registrationYousef Alhouseen1-6/+21
commit bb067a99a0356196c0b89a95721985485ebce5a5 upstream. bnep_add_connection() reads the L2CAP connection without holding the channel lock, then passes its HCI device to register_netdev(). Controller teardown can clear and release that connection concurrently, leaving the network device registration path to dereference a freed parent device. Take a reference to the L2CAP connection while holding the channel lock. Retain it until register_netdev() has taken the parent device reference. Fixes: 65f53e9802db ("Bluetooth: Access BNEP session addresses through L2CAP channel") Reported-by: syzbot+fed5dce4553262f3b35c@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=fed5dce4553262f3b35c Cc: stable@vger.kernel.org Signed-off-by: Yousef Alhouseen <alhouseenyousef@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-18Bluetooth: MGMT: Fix UAF of hci_conn_params in add_device_completeSamuel Page1-0/+3
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 <sam@bynar.io> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-18Bluetooth: L2CAP: Fix UAF in channel timeout by holding conn refMarco Elver1-14/+20
commit b66774b48dd98f07254951f74ea6f513efe7ff8b upstream. l2cap_chan_timeout() runs asynchronously and accesses chan->conn. If the connection is torn down while the timer is running or pending, chan->conn can be freed, leading to a use-after-free when the timer worker attempts to lock conn->lock: | BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:112 [inline] | BUG: KASAN: slab-use-after-free in atomic_long_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:4456 [inline] | BUG: KASAN: slab-use-after-free in __mutex_trylock_fast kernel/locking/mutex.c:161 [inline] | BUG: KASAN: slab-use-after-free in mutex_lock+0x4f/0xa0 kernel/locking/mutex.c:318 | Write of size 8 at addr ffff8881298d9550 by task kworker/2:1/83 | | CPU: 2 UID: 0 PID: 83 Comm: kworker/2:1 Not tainted 7.1.0-rc6-next-20260601-dirty #6 PREEMPT(full) | Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014 | Workqueue: events l2cap_chan_timeout | Call Trace: | <TASK> | instrument_atomic_read_write include/linux/instrumented.h:112 [inline] | atomic_long_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:4456 [inline] | __mutex_trylock_fast kernel/locking/mutex.c:161 [inline] | mutex_lock+0x4f/0xa0 kernel/locking/mutex.c:318 | l2cap_chan_timeout+0x5d/0x1b0 net/bluetooth/l2cap_core.c:422 | process_one_work kernel/workqueue.c:3326 [inline] | process_scheduled_works+0x7c8/0xfb0 kernel/workqueue.c:3409 | worker_thread+0x8a9/0xcf0 kernel/workqueue.c:3490 | kthread+0x346/0x430 kernel/kthread.c:436 | ret_from_fork+0x1a3/0x470 arch/x86/kernel/process.c:158 | ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 | </TASK> | | Allocated by task 320: | l2cap_conn_add+0xa7/0x820 net/bluetooth/l2cap_core.c:7075 | l2cap_connect_cfm+0xdb/0xd70 net/bluetooth/l2cap_core.c:7452 | hci_connect_cfm include/net/bluetooth/hci_core.h:2139 [inline] | hci_remote_features_evt+0x52f/0x9f0 net/bluetooth/hci_event.c:3760 | hci_event_func net/bluetooth/hci_event.c:7796 [inline] | hci_event_packet+0x561/0xa70 net/bluetooth/hci_event.c:7847 | hci_rx_work+0x370/0x890 net/bluetooth/hci_core.c:4040 | process_one_work kernel/workqueue.c:3326 [inline] | process_scheduled_works+0x7c8/0xfb0 kernel/workqueue.c:3409 | worker_thread+0x8a9/0xcf0 kernel/workqueue.c:3490 | kthread+0x346/0x430 kernel/kthread.c:436 | ret_from_fork+0x1a3/0x470 arch/x86/kernel/process.c:158 | ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 | | Freed by task 322: | hci_disconn_cfm include/net/bluetooth/hci_core.h:2154 [inline] | hci_conn_hash_flush+0x101/0x1f0 net/bluetooth/hci_conn.c:2736 | hci_dev_close_sync+0x889/0xde0 net/bluetooth/hci_sync.c:5405 | hci_dev_do_close net/bluetooth/hci_core.c:502 [inline] | hci_unregister_dev+0x1f7/0x370 net/bluetooth/hci_core.c:2679 | vhci_release+0x12a/0x180 drivers/bluetooth/hci_vhci.c:690 | __fput+0x369/0x890 fs/file_table.c:510 | task_work_run+0x160/0x1d0 kernel/task_work.c:233 | get_signal+0xf5b/0x1120 kernel/signal.c:2810 | arch_do_signal_or_restart+0x4d/0x600 arch/x86/kernel/signal.c:337 | __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] | exit_to_user_mode_loop+0x85/0x510 kernel/entry/common.c:98 | do_syscall_64+0x263/0x3d0 arch/x86/entry/syscall_64.c:100 | entry_SYSCALL_64_after_hwframe+0x77/0x7f | | The buggy address belongs to the object at ffff8881298d9400 | which belongs to the cache kmalloc-512 of size 512 | The buggy address is located 336 bytes inside of | freed 512-byte region [ffff8881298d9400, ffff8881298d9600) Fix it by having chan->conn hold a reference to l2cap_conn (via l2cap_conn_get) when the channel is added to the connection, and releasing it in the channel destructor. This ensures the l2cap_conn remains alive as long as the channel exists. A new FLAG_DEL channel flag is introduced to indicate that the channel has been deleted from its connection. l2cap_chan_del() atomically sets this flag using test_and_set_bit() instead of setting chan->conn to NULL. All asynchronous workers (l2cap_chan_timeout, l2cap_ack_timeout, l2cap_monitor_timeout, l2cap_retrans_timeout) and l2cap_chan_send() check FLAG_DEL to determine whether the channel has been torn down, rather than testing chan->conn for NULL. Fixes: 8c8e620467a7 ("Bluetooth: L2CAP: use chan timer to close channels in cleanup_listen()") Cc: <stable@vger.kernel.org> Cc: Siwei Zhang <oss@fourdim.xyz> Cc: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Assisted-by: Gemini:gemini-3.1-pro-preview Reported-by: https://sashiko.dev/#/patchset/20260521021249.3258069-1-oss%40fourdim.xyz Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-06-03Bluetooth: MGMT: Fix backward compatibility with userspaceLuiz Augusto von Dentz1-2/+3
bluetoothd has a bug with makes it send extra bytes as part of MGMT_OP_ADD_EXT_ADV_DATA which are now being checked to be the exact the expected length, relax this so only when the expected length is greater than the data length to cause an error since that would result in accessing invalid memory, otherwise just ignore the extra bytes. Link: https://lore.kernel.org/linux-bluetooth/20260602204749.210857-1-luiz.dentz@gmail.com/T/#u Fixes: d3f7d17960ed ("Bluetooth: MGMT: validate Add Extended Advertising Data length") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-06-03Bluetooth: SCO: Fix data-race on sco_pi fields in sco_connectSeungJu Cheon1-5/+15
sco_sock_connect() copies the destination address into sco_pi(sk)->dst under lock_sock(), then releases the lock and calls sco_connect(), which reads dst, src, setting, and codec without holding lock_sock() in hci_get_route() and hci_connect_sco(). These fields may be modified concurrently by connect(), bind(), or setsockopt() on the same socket, resulting in data-races reported by KCSAN. Fix this by snapshotting dst, src, setting, and codec under lock_sock() at the start of sco_connect() before passing them to hci_get_route() and hci_connect_sco(). BUG: KCSAN: data-race in memcmp+0x45/0xb0 race at unknown origin, with read to 0xffff88800e6b0dd0 of 1 bytes by task 315 on cpu 0: memcmp+0x45/0xb0 hci_connect_acl+0x1b7/0x6b0 hci_connect_sco+0x4d/0xb30 sco_sock_connect+0x27b/0xd60 __sys_connect_file+0xbd/0xe0 __sys_connect+0xe0/0x110 __x64_sys_connect+0x40/0x50 x64_sys_call+0xcad/0x1c60 do_syscall_64+0x133/0x590 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: 9a8ec9e8ebb5 ("Bluetooth: SCO: Fix possible circular locking dependency on sco_connect_cfm") Signed-off-by: SeungJu Cheon <suunj1331@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-06-03Bluetooth: ISO: Fix data-race on iso_pi fields in hci_get_route callsSeungJu Cheon1-16/+44
iso_connect_bis(), iso_connect_cis(), iso_listen_bis(), and iso_conn_big_sync() call hci_get_route() using iso_pi(sk)->dst, iso_pi(sk)->src, and iso_pi(sk)->src_type without holding lock_sock(). These fields may be modified concurrently by connect() or setsockopt() on the same socket, resulting in data-races reported by KCSAN. Fix this by snapshotting the required fields under lock_sock() before calling hci_get_route(). BUG: KCSAN: data-race in memcmp+0x45/0xb0 race at unknown origin, with read to 0xffff8880122135cf of 1 bytes by task 333 on cpu 1: memcmp+0x45/0xb0 hci_get_route+0x27e/0x490 iso_connect_cis+0x4c/0xa10 iso_sock_connect+0x60e/0xb30 __sys_connect_file+0xbd/0xe0 __sys_connect+0xe0/0x110 __x64_sys_connect+0x40/0x50 x64_sys_call+0xcad/0x1c60 do_syscall_64+0x133/0x590 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: 241f51931c35 ("Bluetooth: ISO: Avoid circular locking dependency") Signed-off-by: SeungJu Cheon <suunj1331@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-06-03Bluetooth: ISO: Fix a use-after-free of the hci_conn pointerLuiz Augusto von Dentz1-1/+1
In iso_sock_rebind_bc(), the bis pointer is cached, then the socket lock is dropped: bis = iso_pi(sk)->conn->hcon; /* Release the socket before lookups since that requires hci_dev_lock * which shall not be acquired while holding sock_lock for proper * ordering. */ release_sock(sk); hci_dev_lock(bis->hdev); During the unlocked window, could a concurrent close() destroy the connection and free the bis structure, causing hci_dev_lock(bis->hdev) to access memory after it is freed, fix this by using the hdev reference which was safely acquired via iso_conn_get_hdev(). Fixes: d3413703d5f8 ("Bluetooth: ISO: Add support to bind to trigger PAST") Reported-by: Sashiko <sashiko-bot@kernel.org> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-06-03Bluetooth: ISO: Fix not releasing hdev reference on iso_conn_big_syncLuiz Augusto von Dentz1-0/+1
hci_get_route() returns a reference-counted hci_dev pointer via hci_dev_hold(). The function exits normally or with an error without ever releasing it. Fixes: 07a9342b94a9 ("Bluetooth: ISO: Send BIG Create Sync via hci_sync") Reported-by: Sashiko <sashiko-bot@kernel.org> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-06-03Bluetooth: fix memory leak in error path of hci_alloc_dev()Bharath Reddy1-2/+4
Early failures in Bluetooth HCI UART configuration leak SRCU percpu memory. When device initialization fails before hci_register_dev() completes, the HCI_UNREGISTER flag is never set. As a result, when the device reference count reaches zero, bt_host_release() evaluates this flag as false and falls back to a direct kfree(hdev). Because hci_release_dev() is bypassed, the SRCU struct initialized early in hci_alloc_dev() is never cleaned up, resulting in a leak of percpu memory. Fix the leak by explicitly calling cleanup_srcu_struct() in the fallback (unregistered) branch of bt_host_release() before freeing the device. Reported-by: syzbot+535ecc844591e50588a5@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=535ecc844591e50588a5 Tested-by: syzbot+535ecc844591e50588a5@syzkaller.appspotmail.com Fixes: 1d6123102e9f ("Bluetooth: hci_core: Fix use-after-free in vhci_flush()") Signed-off-by: Bharath Reddy <kbreddy.rpbc@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-06-03Bluetooth: bnep: reject short frames before parsingZhang Cen1-21/+36
A BNEP peer can send a short BNEP SDU. bnep_rx_frame() reads the packet type byte immediately and, for control packets, reads the control opcode and setup UUID-size byte before proving that those bytes are present. bnep_rx_control() also dereferences the control opcode without rejecting an empty control payload. Use skb_pull_data() for the fixed fields in bnep_rx_frame() so a NULL return gates each dereference. Split the control handler so the frame path can pass an opcode that has already been pulled, and keep the byte-buffer wrapper for extension control payloads. For BNEP_SETUP_CONN_REQ, name the UUID-size byte before pulling the setup payload. struct bnep_setup_conn_req carries destination and source service UUIDs after that byte, each uuid_size bytes, so the parser now documents that tuple explicitly instead of leaving the pull length as an opaque multiplication. Validation reproduced this kernel report: KASAN slab-out-of-bounds in bnep_rx_frame.isra.0+0x130c/0x1790 The buggy address belongs to the object at ffff88800c0f7908 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 0 bytes to the right of allocated 1-byte region [ffff88800c0f7908, ffff88800c0f7909) Read of size 1 Call trace: dump_stack_lvl+0xb3/0x140 (?:?) print_address_description+0x57/0x3a0 (?:?) bnep_rx_frame+0x130c/0x1790 (net/bluetooth/bnep/core.c:306) print_report+0xb9/0x2b0 (?:?) __virt_addr_valid+0x1ba/0x3a0 (?:?) srso_alias_return_thunk+0x5/0xfbef5 (?:?) kasan_addr_to_slab+0x21/0x60 (?:?) kasan_report+0xe0/0x110 (?:?) process_one_work+0xfce/0x17e0 (kernel/workqueue.c:3200) worker_thread+0x65c/0xe40 (?:?) __kthread_parkme+0x184/0x230 (?:?) kthread+0x35e/0x470 (?:?) _raw_spin_unlock_irq+0x28/0x50 (?:?) ret_from_fork+0x586/0x870 (?:?) __switch_to+0x74f/0xdc0 (?:?) ret_from_fork_asm+0x1a/0x30 (?:?) Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Assisted-by: Codex:gpt-5.5 Signed-off-by: Zhang Cen <rollkingzzc@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-06-03Bluetooth: hci_sync: reject oversized Broadcast Announcement prependYuqi Xu1-0/+5
Existing advertising instances can already hold the maximum extended advertising payload. When hci_adv_bcast_annoucement() prepends the Broadcast Announcement service data to that payload, the combined data may no longer fit in the temporary buffer used to rebuild the advertising data. Reject that case before copying the existing payload and report the failure through the device log. This keeps the existing advertising data intact and avoids overrunning the temporary buffer. Fixes: 5725bc608252 ("Bluetooth: hci_sync: Fix broadcast/PA when using an existing instance") Cc: stable@kernel.org Reported-by: Yuan Tan <yuantan098@gmail.com> Reported-by: Zhengchuan Liang <zcliangcn@gmail.com> Reported-by: Xin Liu <bird@lzu.edu.cn> Assisted-by: Codex:GPT-5.4 Signed-off-by: Yuqi Xu <xuyq21@lenovo.com> Signed-off-by: Ren Wei <n05ec@lzu.edu.cn> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-06-03Bluetooth: L2CAP: reject BR/EDR signaling packets over MTUsigMichael Bommarito1-0/+46
net/bluetooth/l2cap_core.c:l2cap_sig_channel() accepts BR/EDR signaling packets up to the channel MTU and dispatches each command without enforcing the signaling MTU (MTUsig). A Bluetooth BR/EDR peer within radio range can send a fixed-channel CID 0x0001 packet that is larger than MTUsig and contains many L2CAP_ECHO_REQ commands before pairing. In a real-radio stock-kernel run, one 681-byte signaling packet containing 168 zero-length ECHO_REQ commands made the target transmit 168 ECHO_RSP frames over about 220 ms. Impact: a Bluetooth BR/EDR peer within radio range, before pairing, can force 168 ECHO_RSP frames from one 681-byte fixed-channel signaling packet containing packed ECHO_REQ commands. Define Linux's BR/EDR signaling MTU as the spec minimum of 48 bytes and reject any larger signaling packet with one L2CAP_COMMAND_REJECT_RSP carrying L2CAP_REJ_MTU_EXCEEDED before any command is dispatched. The Bluetooth Core spec wording for MTUExceeded says the reject identifier shall match the first request command in the packet, and that packets containing only responses shall be silently discarded. Linux intentionally deviates from that prescription: silently discarding desynchronizes the peer because the remote stack never learns its responses were dropped, and locating the first request command requires walking command headers past MTUsig, i.e. processing bytes from a packet we have already decided is too large to process. We therefore always emit one reject and use the identifier from the first command header, a single fixed-offset byte read. The unrestricted BR/EDR signaling parser and ECHO_REQ response path both trace to the initial git import; no later introducing commit is available for a Fixes tag. Cc: stable@vger.kernel.org Suggested-by: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Link: https://lore.kernel.org/r/20260518002800.1361430-1-michael.bommarito@gmail.com Link: https://lore.kernel.org/r/20260520135034.1060859-1-michael.bommarito@gmail.com Link: https://lore.kernel.org/r/20260521000555.3712030-1-michael.bommarito@gmail.com Assisted-by: Claude:claude-opus-4-7 Assisted-by: Codex:gpt-5-5-xhigh Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-06-03Bluetooth: RFCOMM: validate skb length in MCC handlersSeungJu Cheon1-18/+49
The RFCOMM MCC handlers cast skb->data to protocol-specific structs without validating skb->len first. A malicious remote device can send truncated MCC frames and trigger out-of-bounds reads in these handlers. Fix this by using skb_pull_data() to validate and access the required data before dereferencing it. rfcomm_recv_rpn() requires special handling since ETSI TS 07.10 allows 1-byte RPN requests. Handle this by validating only the DLCI byte first, and validating the full struct only when len > 1. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Suggested-by: Muhammad Bilal <meatuni001@gmail.com> Signed-off-by: SeungJu Cheon <suunj1331@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-06-03Bluetooth: MGMT: validate advertising TLV before type checksZhang Cen1-6/+6
tlv_data_is_valid() reads each advertising data field length from data[i], then inspects data[i + 1] for managed EIR types before checking that the current field still fits inside the supplied buffer. A malformed field whose length byte is the last byte of the buffer can therefore make the parser read one byte past the advertising data. KASAN reported the following when a malformed MGMT_OP_ADD_ADVERTISING request reached that path: BUG: KASAN: vmalloc-out-of-bounds in tlv_data_is_valid() Read of size 1 Call trace: tlv_data_is_valid() add_advertising() hci_mgmt_cmd() hci_sock_sendmsg() Move the existing element-length check before any type-octet inspection so each non-empty element is proven to contain its type byte before the parser looks at data[i + 1]. Fixes: 2bb36870e8cb ("Bluetooth: Unify advertising instance flags check") Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de> Signed-off-by: Zhang Cen <rollkingzzc@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-06-03Bluetooth: RFCOMM: hold listener socket in rfcomm_connect_ind()Zhang Cen1-4/+22
rfcomm_get_sock_by_channel() scans rfcomm_sk_list under the list lock, but returns the selected listener after dropping that lock without taking a reference. rfcomm_connect_ind() then locks the listener, queues a child socket on it, and may notify it after unlocking it. The buggy scenario involves two paths, with each column showing the order within that path: rfcomm_connect_ind(): listener close: 1. Find parent in 1. close() enters rfcomm_get_sock_by_channel() rfcomm_sock_release(). 2. Drop rfcomm_sk_list.lock 2. rfcomm_sock_shutdown() without pinning parent. closes the listener. 3. Call lock_sock(parent) and 3. rfcomm_sock_kill() bt_accept_enqueue(parent, unlinks and puts parent. sk, true). 4. Read parent flags and may 4. parent can be freed. call sk_state_change(). If close wins the race, parent can be freed before rfcomm_connect_ind() reaches lock_sock(), bt_accept_enqueue(), or the deferred-setup callback. Take a reference on the listener before leaving rfcomm_sk_list.lock. After lock_sock() succeeds, recheck that it is still in BT_LISTEN before queueing a child, cache the deferred-setup bit while the parent is locked, and drop the reference after the last parent use. KASAN reported a slab-use-after-free in lock_sock_nested() from rfcomm_connect_ind(), with the freeing stack going through rfcomm_sock_kill() and rfcomm_sock_release(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Zhang Cen <rollkingzzc@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-05-28Bluetooth: hci_sync: Reset device counters in hci_dev_close_sync()Heitor Alves de Siqueira1-0/+4
Before resetting or closing the device, protocol counters should also be zeroed. Fixes: d0b137062b2d ("Bluetooth: hci_sync: Rework init stages") Signed-off-by: Heitor Alves de Siqueira <halves@igalia.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-05-28Bluetooth: hci_sync: Set HCI_CMD_DRAIN_WORKQUEUE during device closeHeitor Alves de Siqueira1-0/+8
Since hci_dev_close_sync() can now be called during the reset path, we should also set HCI_CMD_DRAIN_WORKQUEUE. This avoids queuing timeouts while the hdev workqueue is being drained. Fixes: 877afadad2dc ("Bluetooth: When HCI work queue is drained, only queue chained work") Signed-off-by: Heitor Alves de Siqueira <halves@igalia.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-05-28Bluetooth: hci_core: Rework hci_dev_do_reset() to use hci_sync functionsHeitor Alves de Siqueira1-40/+3
The current HCI reset function in hci_core.c duplicates most of the work done by hci_dev_close_sync(), and doesn't handle LE, advertising or discovery. Instead of porting these to hci_dev_do_reset(), directly call the close/open functions from hci_sync to reset the hdev. MGMT now notifies when a user performs a reset. Suggested-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Heitor Alves de Siqueira <halves@igalia.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-05-28Bluetooth: ISO: serialize iso_sock_clear_timer with socket lockMuhammad Bilal1-1/+1
iso_sock_close() calls iso_sock_clear_timer() before acquiring lock_sock(sk). iso_sock_clear_timer() reads iso_pi(sk)->conn twice without the socket lock held: if (!iso_pi(sk)->conn) return; cancel_delayed_work(&iso_pi(sk)->conn->timeout_work); Concurrently, iso_conn_del() executes under lock_sock(sk) and calls iso_chan_del(), which sets iso_pi(sk)->conn to NULL and may result in the final reference to the connection being dropped: CPU0 CPU1 ---- ---- iso_sock_clear_timer() if (conn != NULL) ... lock_sock(sk) iso_chan_del() iso_pi(sk)->conn = NULL cancel_delayed_work(conn) /* NULL deref or UAF */ iso_pi(sk)->conn is not stable across the unlock window, causing a NULL pointer dereference or use-after-free. Serialize iso_sock_clear_timer() with the socket lock by moving it inside lock_sock()/release_sock(), matching the pattern used in iso_conn_del() and all other call sites. Fixes: ccf74f2390d60a2f9a75ef496d2564abb478f46a ("Bluetooth: Add BTPROTO_ISO socket type") Cc: stable@vger.kernel.org Signed-off-by: Muhammad Bilal <meatuni001@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-05-28Bluetooth: ISO: fix UAF in iso_recv_frameMuhammad Bilal1-3/+7
iso_recv_frame reads conn->sk under iso_conn_lock but releases the lock before using sk, with no reference held. A concurrent iso_sock_kill() can free sk in that window, causing use-after-free on sk->sk_state and sock_queue_rcv_skb(). Fix by replacing the bare pointer read with iso_sock_hold(conn), which calls sock_hold() while the spinlock is held, atomically elevating the refcount before the lock drops. Add a drop_put label so sock_put() is called on all exit paths where the hold succeeded. Fixes: ccf74f2390d60a2f9a75ef496d2564abb478f46a ("Bluetooth: Add BTPROTO_ISO socket type") Cc: stable@vger.kernel.org Signed-off-by: Muhammad Bilal <meatuni001@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-05-28Bluetooth: L2CAP: Fix possible crash on l2cap_ecred_conn_rspLuiz Augusto von Dentz1-5/+22
If dcid is received for an already-assigned destination CID the spec requires that both channels to be discarded, but calling l2cap_chan_del may invalidate the tmp cursor created by list_for_each_entry_safe and in fact it is the wrong procedure as the chan->dcid may be assigned previously it really needs to be disconnected. Calling l2cap_chan_clone directly may still lead to l2cap_chan_del so instead schedule l2cap_chan_timeout with delay 0 to close the channel asynchronously. Fixes: 15f02b910562 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-05-28Bluetooth: l2cap: clear chan->ident on ECRED reconfiguration successZhenghang Xiao1-2/+8
l2cap_ecred_reconf_rsp() returns early on success without clearing chan->ident. Every other L2CAP response handler (l2cap_ecred_conn_rsp, l2cap_le_connect_rsp, l2cap_config_rsp) clears chan->ident after a successful transaction to prevent the channel from matching subsequent responses with the recycled ident value. A remote attacker that completed a reconfiguration as the peer can replay a failure response with the stale ident, causing the kernel to match and destroy the already-established channel via l2cap_chan_del(chan, ECONNRESET). Clear chan->ident for all matching channels on success, and harden the failure path by using l2cap_chan_hold_unless_zero() consistent with other L2CAP handlers (l2cap_le_command_rej, __l2cap_get_chan_by_ident). Fixes: 15f02b910562 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode") Signed-off-by: Zhenghang Xiao <kipreyyy@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-05-27Bluetooth: hci_sync: fix UAF in hci_le_create_cis_syncDoruk Tan Ozturk1-1/+3
hci_le_create_cis_sync() dereferences conn->conn_timeout after releasing both rcu_read_lock() and hci_dev_lock(hdev). The conn pointer was obtained from an RCU-protected iteration over hdev->conn_hash.list and is not valid once these locks are dropped. A concurrent disconnect can free the hci_conn between the unlock and the dereference, causing a use-after-free read. The cancellation mechanism in hci_conn_del() cannot prevent this because hci_le_create_cis_pending() queues hci_create_cis_sync with data=NULL: hci_cmd_sync_queue(hdev, hci_create_cis_sync, NULL, NULL); While hci_conn_del() dequeues with data=conn: hci_cmd_sync_dequeue(hdev, NULL, conn, NULL); Since NULL != conn, the lookup in _hci_cmd_sync_lookup_entry() never matches, and the pending work item is not cancelled. Fix this by saving conn->conn_timeout into a local variable while the locks are still held, so the stale conn pointer is never dereferenced after unlock. This is the same class of bug as the one fixed by commit 035c25007c9e ("Bluetooth: hci_sync: Fix UAF on le_read_features_complete") which addressed the identical pattern in a different function. This vulnerability was identified using 0sec.ai, an open-source automated security auditing platform (https://github.com/0sec-labs). Fixes: c09b80be6ffc ("Bluetooth: hci_conn: Fix not waiting for HCI_EVT_LE_CIS_ESTABLISHED") Cc: stable@vger.kernel.org Reported-by: Doruk Tan Ozturk <doruk@0sec.ai> Signed-off-by: Doruk Tan Ozturk <doruk@0sec.ai> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2026-05-27Bluetooth: 6lowpan: check skb_clone() return value in send_mcast_pkt()Zhao Dongdong1-0/+2
The skb_clone() function can return NULL if memory allocation fails. send_mcast_pkt() calls skb_clone() without checking the return value, which can lead to a NULL pointer dereference in send_pkt() when it dereferences skb->data. Add a NULL check after skb_clone() and skip the peer if the clone fails. Fixes: 18722c247023 ("Bluetooth: Enable 6LoWPAN support for BT LE devices") Signed-off-by: Zhao Dongdong <zhaodongdong@kylinos.cn> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>