5858 Commits
Author SHA1 Message Date
Chengfeng Ye 848a7a91c7 Bluetooth: hci_core: Serialize SCO and ISO scheduling with teardown
hci_low_sent() selects a connection under RCU but drops the read lock
before calculating its quota and returning it to the scheduler. The
connection is then used without lifetime protection by hci_sched_iso()
and hci_sched_sco().

After the TX worker drops the RCU read lock, hci_abort_conn_sync() on
hdev->req_workqueue can remove the connection from the hash, complete
synchronize_rcu(), purge its queues and release it. The TX worker on
hdev->workqueue can then access the freed connection in hci_quote_sent()
or while dequeuing packets and updating conn->sent.

KASAN reported:

  BUG: KASAN: slab-use-after-free in hci_low_sent+0x730/0x840
  Workqueue: hci0 hci_tx_work
  Call Trace:
   hci_low_sent+0x730/0x840
   hci_sched_iso+0x25e/0x4d0
   hci_tx_work+0x239/0xcb0

  Allocated by task 93:
   __hci_conn_add+0x16f/0x1b40
   hci_bind_bis+0x782/0x17b0
   hci_connect_bis+0xa0/0x510
   iso_sock_connect+0x589/0x1050

  Freed by task 88:
   kfree+0x131/0x3c0
   device_release+0xc8/0x240
   kobject_put+0x14d/0x280
   hci_conn_del+0x55a/0xe80
   hci_disconnect_sync+0x156/0x180
   hci_abort_conn_sync+0x3e7/0x940
   hci_cmd_sync_work+0x13c/0x290

Hold hci_dev_lock() across connection selection and transmission in both
SCO and ISO scheduling, serializing them with connection teardown. This
also prevents queuing completion timestamps after the connection queues
have been purged. Extending RCU across transmission would be unsafe
because the transmit path can sleep. Keep the ISO timeout check outside
the mutex since hci_link_tx_to() takes it itself.

The preceding channel fix already holds this mutex in the ACL and LE
schedulers, which call the SCO scheduler between packets. Move the SCO
body to __hci_sched_sco(), assert that its caller holds the mutex, and
use it directly from these locked paths. Keep a locking hci_sched_sco()
wrapper for the direct calls from hci_tx_work(). This avoids recursively
acquiring the device mutex while preserving the scheduling order.

Remove the obsolete claim that connection removal disables TX.

Fixes: bf4c632524 ("Bluetooth: convert conn hash to RCU")
Cc: [email protected]
Assisted-by: LLM
Signed-off-by: Chengfeng Ye <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-28 11:00:20 -04:00
Chengfeng Ye f4845ab191 Bluetooth: hci_core: Serialize ACL scheduling with channel deletion
hci_chan_sent() selects a channel under RCU but drops the read lock before
accessing chan->conn and returning the channel. The ACL and LE schedulers
then use its packet queue and update its transmit counters without any
protection against channel deletion.

After TX selects a channel and releases RCU, a disconnect command timeout
on the separate request workqueue can run hci_conn_failed() and
l2cap_conn_del(). hci_chan_del() can then unlink the channel, complete
synchronize_rcu(), purge its queue and free it before TX resumes. This
causes use-after-free both in hci_chan_sent() and in its callers.

KASAN reported:

  BUG: KASAN: slab-use-after-free in hci_chan_sent+0x892/0x9b0
  Workqueue: hci0 hci_tx_work
  Call Trace:
   hci_chan_sent+0x892/0x9b0
   hci_tx_work+0x5e6/0xb70
  Allocated by task 91:
   hci_chan_create+0xe3/0x350
   l2cap_conn_add.part.0+0x12/0xa30
   l2cap_chan_connect+0x110d/0x1b60
   l2cap_sock_connect+0x310/0x530
  Freed by task 99:
   hci_chan_del+0x11f/0x170
   l2cap_conn_del+0x4f1/0x800
   l2cap_connect_cfm+0x88c/0xd30
   hci_conn_failed+0x150/0x250
   hci_abort_conn_sync+0x3e3/0x800
   hci_cmd_sync_run+0x7e/0xc0
   hci_abort_conn+0x105/0x1f0
   disconnect_sync+0x157/0x290
   hci_cmd_sync_work+0x13c/0x290

Hold the existing device mutex across channel selection and transmission
in both schedulers to serialize them with channel teardown. Keep timeout
handling outside the critical sections because hci_link_tx_to() acquires
the same mutex. This also permits the transmit path to sleep, unlike
extending the RCU read-side critical section across packet submission.

Fixes: 3eff45eaf8 ("Bluetooth: convert tx_task to workqueue")
Cc: [email protected]
Assisted-by: LLM
Signed-off-by: Chengfeng Ye <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-28 11:00:20 -04:00
Chengfeng Ye 81a2345f19 Bluetooth: Serialize SMP remote OOB data access
build_pairing_cmd() looks up remote OOB data and copies its contents
without holding hdev->lock, which serializes the list's writers. After
SMP finds an entry, a concurrent management Remove Remote OOB Data
command can unlink and free it before SMP reads its present flag or
copies its random and confirmation values. Removal can also invalidate
an entry while the lookup is still traversing the list.

KASAN reported:

  BUG: KASAN: slab-use-after-free in build_pairing_cmd+0x948/0x9b0
  Call Trace:
   build_pairing_cmd+0x948/0x9b0
   smp_recv_cb+0x459f/0x8110
   l2cap_recv_frame+0xf14/0x9190
   l2cap_recv_acldata+0xa64/0xd40
   hci_rx_work+0x4ca/0x730

  Allocated by task 87:
   hci_add_remote_oob_data+0x11d/0x530
   add_remote_oob_data+0x282/0x400
   hci_sock_sendmsg+0x1033/0x1ea0

  Freed by task 93:
   hci_remote_oob_data_clear+0x108/0x1c0
   remove_remote_oob_data+0x198/0x220
   hci_sock_sendmsg+0x1033/0x1ea0

Taking hdev->lock in build_pairing_cmd() would recurse for callers that
already hold it and invert the device-to-L2CAP lock order on the receive
path. Add a per-device remote_oob_lock instead, held across the SMP
lookup and copies and by the add, remove and clear helpers. Cover
initialization and in-place updates as well, so SMP cannot read partially
initialized or updated OOB values. Release the mutex on allocation
failure, preserving the existing error return.

The new critical sections acquire no device, connection or channel locks.
Writers retain their existing hdev->lock protection, which continues to
serialize the other readers without changing their locking or behavior.

Link: https://lore.kernel.org/r/[email protected]
Fixes: 02b05bd8b0 ("Bluetooth: Set SMP OOB flag if OOB data is available")
Cc: [email protected]
Signed-off-by: Chengfeng Ye <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-28 11:00:20 -04:00
Chengfeng Ye 2d696c1ed3 Bluetooth: RFCOMM: Fix initial port reference race
For RFCOMM_RELEASE_ONHUP devices, rfcomm_tty_install() and
__rfcomm_release_dev() both use RFCOMM_TTY_OWNED to decide who drops the
initial tty_port reference. The release path tests the bit separately
from the install path setting it, so both can drop that reference.

The synchronous hangup does not prevent this race: port->tty is not
assigned until tty_port_open(), after installation. The following
interleaving is possible:

  1. Install and release each obtain a reference with rfcomm_dev_get().
  2. Release observes RFCOMM_TTY_OWNED clear.
  3. Install sets RFCOMM_TTY_OWNED and drops the initial reference.
  4. Release drops the same initial reference again.
  5. TTY cleanup drops its reference and frees the device.
  6. Release performs its final tty_port_put() on the freed port.

KASAN reported:

  BUG: KASAN: slab-use-after-free in tty_port_put+0x22/0x190
  Write of size 4 at addr ffff8881001d3d5c by task poc/92

  Call Trace:
   tty_port_put+0x22/0x190
   rfcomm_dev_ioctl+0x1d4/0x1930
   sock_do_ioctl+0x110/0x260
   sock_ioctl+0x380/0x590
   __x64_sys_ioctl+0x134/0x1c0

  Allocated by task 88:
   rfcomm_dev_ioctl+0x8f6/0x1930
   sock_do_ioctl+0x110/0x260
   sock_ioctl+0x380/0x590
   __x64_sys_ioctl+0x134/0x1c0

  Freed by task 65:
   kfree+0x131/0x3c0
   rfcomm_dev_destruct+0x23b/0x2f0
   release_one_tty+0xc1/0x370
   process_one_work+0x661/0x1090

Use test_and_set_bit() in both paths so that only the caller that changes
RFCOMM_TTY_OWNED from clear to set drops the initial reference. Each path
keeps its own lookup reference until release or TTY cleanup, preserving
the existing callback ordering and error handling.

Fixes: 80ea73378a ("Bluetooth: Fix unreleased rfcomm_dev reference")
Cc: [email protected]
Assisted-by: LLM
Signed-off-by: Chengfeng Ye <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-28 11:00:20 -04:00
Chengfeng Ye 8ed67535fd Bluetooth: hci_sync: Fix inquiry cache use-after-free
The sync command worker holds hdev->req_lock, but inquiry-cache updates
and flushes use hdev->lock. Both hci_acl_create_conn_sync() and
hci_stop_discovery_sync() look up entries and read their fields without
taking hdev->lock.

After either lookup returns, a concurrent HCIINQUIRY ioctl can acquire
hdev->lock and flush the cache, freeing the entry. The worker then reads
the freed entry while preparing a create-connection or remote-name-cancel
command. The list traversal also races with cache updates and removal.

KASAN reported these accesses:

  BUG: KASAN: slab-use-after-free in hci_acl_create_conn_sync+0x5f1/0x650
  Workqueue: hci0 hci_cmd_sync_work
  Call Trace:
   hci_acl_create_conn_sync+0x5f1/0x650
   hci_cmd_sync_work+0x13c/0x290

  Allocated by task 90:
   hci_inquiry_cache_update+0x3e6/0x7d0
   hci_inquiry_result_evt+0x3cb/0x560

  Freed by task 93:
   hci_inquiry_cache_flush+0x111/0x2b0
   hci_inquiry+0x2f2/0x780
   hci_sock_ioctl+0x269/0x5f0

  BUG: KASAN: slab-use-after-free in hci_stop_discovery_sync+0x3b1/0x3c0
  Workqueue: hci0 hci_cmd_sync_work
  Call Trace:
   hci_stop_discovery_sync+0x3b1/0x3c0
   hci_cmd_sync_work+0x173/0x300

  Allocated by task 86:
   hci_inquiry_cache_update+0x483/0x940
   hci_inquiry_result_evt+0x3cb/0x560

  Freed by task 91:
   hci_inquiry_cache_flush+0x13e/0x2f0
   hci_inquiry+0x2f2/0x780
   hci_sock_ioctl+0x269/0x5f0

Hold hdev->lock across each lookup and all reads from its result. Copy the
remote address before unlocking so discovery cancellation does not retain
a cache entry pointer. Release the lock before sending synchronous HCI
commands, since their completion handlers may need the same lock.

Fixes: cf75ad8b41 ("Bluetooth: hci_sync: Convert MGMT_SET_POWERED")
Fixes: 45340097ce ("Bluetooth: hci_conn: Only do ACL connections sequentially")
Cc: [email protected]
Signed-off-by: Chengfeng Ye <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-28 11:00:20 -04:00
Nguyen Ngoc Thang b1f24c1ab5 Bluetooth: hci_sync: don't drain cmd_sync backlog on unregister
hci_unregister_dev() disables cmd_work and cmd_timer, then calls
hci_cmd_sync_clear(), whose cancel_work_sync() waits for
hci_cmd_sync_work() to return. That worker dequeues and runs every
entry on cmd_sync_work_list. With cmd_work disabled nothing reaches
the controller, so each queued HCI command waits the full
HCI_CMD_TIMEOUT (2s).

The backlog has no bound. Userspace can keep queuing MGMT commands
such as MGMT_OP_GET_CLOCK_INFO against a controller that doesn't
answer. Closing /dev/vhci then blocks in vhci_release() for
backlog * 2s:

  INFO: task syz-executor:5749 blocked for more than 143 seconds.
   cancel_work_sync
   hci_cmd_sync_clear
   hci_unregister_dev
   vhci_release

In a local reproduction the backlog held more than 5000 entries,
which comes to hours of hang.

Stop the worker from taking new entries once HCI_UNREGISTER is set,
and wake any request still waiting with -ENODEV before cancelling
the work. The entries left over are destroyed with -ECANCELED by the
existing sweep in hci_cmd_sync_clear(). They stay on the list until
the work has stopped, so hci_cmd_sync_dequeue() and friends still see
them. A callback already running may still issue another command,
which delays unregister by at most one timeout per remaining command,
not by the whole backlog.

Fixes: 008ee9eb8a ("Bluetooth: hci_sync: Fix not processing all entries on cmd_sync_work")
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=217e3f1283cafe80586e
Signed-off-by: Nguyen Ngoc Thang <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-28 11:00:20 -04:00
Chengfeng Ye 1a572db43c Bluetooth: hci_core: Serialize fragmented ISO packet queueing
The fragmented path in hci_queue_iso() calls __skb_queue_tail() without
holding conn->data_q.lock. The socket lock serializes senders, but the
transmit worker can concurrently remove packets from this queue using
skb_dequeue().

After an insertion saves the old tail pointer, hci_sched_iso() can dequeue
that packet and pass it to the driver. The driver can free the packet
before the insertion resumes and writes to the old tail's next pointer,
causing a use-after-free. Concurrent updates can also corrupt the queue.

KASAN reported:

  BUG: KASAN: slab-use-after-free in hci_send_iso+0xc7d/0xe10
  Call Trace:
   hci_send_iso+0xc7d/0xe10
   iso_sock_sendmsg+0x710/0x900
   __sys_sendto+0x34a/0x3a0

  Allocated by task 86:
   __alloc_skb+0xdd/0x820
   alloc_skb_with_frags+0x7e/0x770
   sock_alloc_send_pskb+0x67a/0x820
   bt_skb_sendmsg.constprop.0+0xc0/0x6c0
   iso_sock_sendmsg+0x44e/0x900

  Freed by task 90:
   kmem_cache_free+0xcb/0x3d0
   vhci_read+0x33f/0x4d0
   vfs_read+0x177/0xa20

Hold the queue lock across the entire fragment batch, as hci_queue_acl()
does, to serialize insertion against dequeue while preserving fragment
ordering.

Fixes: 26afbd826e ("Bluetooth: Add initial implementation of CIS connections")
Cc: [email protected]
Signed-off-by: Chengfeng Ye <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-28 11:00:20 -04:00
Chengfeng Ye 024e05f73a Bluetooth: hci_conn: Lock parent access during enhanced SCO setup
Bluetooth: hci_conn: Lock parent access during enhanced SCO setup

hci_enhanced_setup_sync() runs on the request workqueue without the
hci_dev_lock held by its caller when setup was queued. Its CVSD
capability check and find_next_esco_param() dereference conn->parent
while the receive workqueue can unlink and release that parent.

The following interleaving can cause a use-after-free:

  hci_enhanced_setup_sync()       hci_disconn_complete_evt()
  load conn->parent
                                 hci_dev_lock()
                                 hci_conn_del(ACL parent)
                                   unlink SCO child
                                   drop link's parent reference
                                   clear child->parent
                                   release ACL parent
                                     bt_link_release()
                                       kfree(parent)
                                 hci_dev_unlock()
  read parent->features[0][3]

The reference held for the queued SCO child does not keep its ACL parent
alive after unlinking. Commit 42de40abe2 ("Bluetooth: hci_conn: fix the
SCO setup context lifetime") protects the child stored in the queued
context, but leaves these parent accesses unprotected.

With a 40 ms diagnostic delay after loading conn->parent, an instrumented
kernel based on fd179f8a05, which already contains 42de40abe2,
reported:

  BUG: KASAN: slab-use-after-free in hci_enhanced_setup_sync+0xda5/0xdf0
  Read of size 1 at addr ffff888102204047 by task kworker/u17:0/93
  Call Trace:
   hci_enhanced_setup_sync+0xda5/0xdf0
   hci_cmd_sync_work+0x13c/0x290
   process_one_work+0x6b4/0x10e0

  Allocated by task 92:
   __hci_conn_add+0x304/0x1df0
   hci_connect_acl+0x349/0x3e0
   hci_connect_sco+0x3b/0x9a0
   sco_sock_connect+0x475/0xca0

  Freed by task 94:
   kfree+0x121/0x3c0
   bt_link_release+0x79/0xa0
   device_release+0xc8/0x240
   kobject_put+0x14d/0x280
   hci_conn_del+0x524/0xe30
   hci_disconn_complete_evt+0x403/0x8c0
   hci_event_packet+0x71b/0xb20
   hci_rx_work+0x293/0x730

The accessed address is 71 bytes into the freed ACL parent, at its
features[0][3] byte; the queued SCO child is a different object. The
diagnostic preserves the loaded parent across the delay, matching the
unmodified compiled capability check, and does not change the parent
references or teardown path.

Hold hci_dev_lock() across the codec switch, including every call to
find_next_esco_param(), and release it on all selection errors. Keep
configure_datapath_sync() outside the critical section because it waits
for HCI events. Preserve parameter selection and existing return values.

Fixes: e07a06b4eb ("Bluetooth: Convert SCO configure_datapath to hci_sync")
Cc: [email protected]
Assisted-by: GPT-6-Astra
Signed-off-by: Chengfeng Ye <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-28 11:00:20 -04:00
Sang-Hoon Choi d1ac915fb4 Bluetooth: hci_core: free the HCI ID if naming fails
hci_register_dev() allocates an ID before calling dev_set_name().
If naming fails, it returns without releasing that ID. The device has
not been registered and hdev->id has not been assigned, so the normal
unregister path cannot release it.

Free the allocated ID before returning the naming error.

Fixes: dcda165706 ("Bluetooth: hci_core: Fix build warnings")
Reported-by: Changyul Lee <[email protected]>
Assisted-by: LLM
Signed-off-by: Sang-Hoon Choi <[email protected]>
Reported-by: Changyul Lee <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-23 09:30:50 -04:00
Linmao Li 74847177ec Bluetooth: hci_core: Fix inquiry cache timestamps on 64-bit systems
On 64-bit systems, outgoing BR/EDR connections always fall back to page
scan repetition mode R2 with no clock offset once the system has been
up for more than five minutes, even when inquiry found the peer only
seconds earlier. This lengthens paging and can increase the risk of a
Page Timeout.

The inquiry cache stores jiffies in __u32 timestamps, but its age
helpers subtract them from unsigned long jiffies. INITIAL_JIFFIES casts
-300 * HZ through unsigned int, so jiffies crosses 2^32 five minutes
after boot on 64-bit systems. Assigning it to __u32 then drops the upper
32 bits. In one trace, a 7.6-second-old entry (HZ=1000) was reported as
2^32 + 7620 ticks old and rejected by hci_acl_create_conn_sync().
hci_inquiry() is affected by the same truncation when checking the whole
cache. 32-bit systems are unaffected because unsigned long is 32 bits
wide there.

Use unsigned long for both timestamps so they have the same width as
jiffies on 32-bit and 64-bit systems, and update the debugfs format
specifier accordingly.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: [email protected]
Signed-off-by: Linmao Li <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-23 09:30:21 -04:00
Hui Peng 6d91041bb3 Bluetooth: RFCOMM: Reject short EA=0 frames in rfcomm_recv_frame()
While rfcomm_recv_frame() verifies that skb->len is at least
sizeof(*hdr) + 1 (4 bytes: 3-byte header + 1-byte FCS), an RFCOMM frame
with an extended 2-byte length field (!__test_ea(hdr->len)) has a 4-byte
header plus a 1-byte FCS (5 bytes minimum, sizeof(*hdr) + 2).

When a 4-byte RFCOMM frame with EA == 0 arrives:
1. The initial skb->len < sizeof(*hdr) + 1 check passes (4 < 4 is false).
2. Trimming the FCS byte decrements skb->len to 3.
3. If __check_fcs() succeeds, skb_pull(skb, 4) fails (4 > 3) and returns
   NULL without advancing skb->data.
4. Because the return value of skb_pull() is ignored, the un-pulled
   3-byte struct rfcomm_hdr remains at skb->data and is either queued as
   application payload via rfcomm_recv_data() or parsed as a multiplexer
   control command via rfcomm_recv_mcc() on DLCI 0.

Fix this by extending the length check in rfcomm_recv_frame() to also
require skb->len >= sizeof(*hdr) + 2 when !__test_ea(hdr->len).

Fixes: b230e5bf50 ("Bluetooth: RFCOMM: validate skb length in rfcomm_recv_frame")
Assisted-by: LLM
Signed-off-by: Hui Peng <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-21 09:37:20 -04:00
Hui Peng 46f8ffd0a1 Bluetooth: RFCOMM: fix NULL dereference of dlc->session in RFCOMM_CONNINFO
The RFCOMM_CONNINFO getsockopt handler accepts a socket that is not
connected as long as deferred setup is enabled:

	if (sk->sk_state != BT_CONNECTED &&
				!rfcomm_pi(sk)->dlc->defer_setup) {
		err = -ENOTCONN;
		break;
	}
	l2cap_sk = rfcomm_pi(sk)->dlc->session->sock->sk;

dlc->defer_setup is set in rfcomm_sock_init() when rfcomm_connect_ind()
creates a child socket for an incoming connection on a listening socket
that has BT_DEFER_SETUP enabled. It is never cleared afterwards. The
session, however, can go away underneath it.

rfcomm_recv_disc() forces the dlc state before tearing it down:

	d->state = BT_CLOSED;
	__rfcomm_dlc_close(d, err);

The RFCOMM_DEFER_SETUP early return in __rfcomm_dlc_close() only covers
BT_CONNECT, BT_CONFIG, BT_OPEN and BT_CONNECT2, so with the state
already BT_CLOSED that switch does not match and the function falls
through to rfcomm_dlc_unlink(), which sets d->session = NULL, while
d->defer_setup stays 1.

A getsockopt(SOL_RFCOMM, RFCOMM_CONNINFO) on the accepted socket after
that point therefore skips the -ENOTCONN path -- sk->sk_state is
BT_CLOSED, but dlc->defer_setup is still set -- and dereferences the
NULL session. No race is needed: once the DISC has been processed, the
dereference is unconditional.

Reproduced on a KASAN kernel under QEMU 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 and sends SABM for a channel bound with
BT_DEFER_SETUP, and sends DISC for that dlci after the socket has been
accepted. getsockopt(SOL_RFCOMM, RFCOMM_CONNINFO) on the accepted
socket then hits:

 Oops: general protection fault, probably for non-canonical address
 0xdffffc0000000002: 0000 [#1] SMP KASAN PTI
 KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
 CPU: 1 UID: 0 PID: 150 Comm: init Tainted: G B 7.3.0-rc3-g5dd1818b15d9
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
 RIP: 0010:rfcomm_sock_getsockopt+0x529/0x780
 Call Trace:
  <TASK>
  do_sock_getsockopt+0x3ad/0x7d0
  __sys_getsockopt+0x10e/0x1b0
  __x64_sys_getsockopt+0xc2/0x160
  do_syscall_64+0xda/0x4b0
  entry_SYSCALL_64_after_hwframe+0x77/0x7f
  </TASK>

0x10 is the offset of sock in struct rfcomm_session;
rfcomm_sock_getsockopt_old() is inlined into rfcomm_sock_getsockopt().

Commit 43a556b2fd ("Bluetooth: RFCOMM: take rfcomm_mutex for the
deferred setup accept") fixed the same "a remote DISC clears the session
while deferred setup is still flagged" problem in rfcomm_dlc_accept();
this is the remaining instance of it, in the getsockopt path.

Deferred setup only leaves a socket usable here once it has reached
BT_CONNECT2, so restrict the exception to that state and check that a
session is actually present before following it.

Fixes: bb23c0ab82 ("Bluetooth: Add support for deferring RFCOMM connection setup")
Cc: [email protected]
Assisted-by: LLM
Signed-off-by: Hui Peng <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-21 09:37:20 -04:00
Hui Peng f0ca020cbb Bluetooth: bnep: fix out-of-bounds reads on short RX/TX frames and control fallthrough
Fix multiple out-of-bounds reads in Bluetooth BNEP frame processing:

1. In bnep_rx_frame() and bnep_ctrl_frame() (net/bluetooth/bnep/core.c),
   use pskb_may_pull() to verify the BNEP header, control type byte,
   filter count, and extension headers exist before reading them, and
   return 0 after handling BNEP_CONTROL instead of falling through to
   Ethernet frame submission when no extension headers follow.
2. In bnep_net_xmit() (net/bluetooth/bnep/netdev.c), verify skb->len >=
   ETH_HLEN with pskb_may_pull() before reading the 14-byte Ethernet
   header to prevent an out-of-bounds heap read and infoleak on short
   AF_PACKET TX frames.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Assisted-by: LLM
Signed-off-by: Hui Peng <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-21 09:37:19 -04:00
Aldo Ariel Panzardo b5dbb41b21 Bluetooth: mgmt: fix race in read_unconf_index_list()
read_unconf_index_list() counts unconfigured controllers before allocating
its response, then checks the device flags again while filling it.

hci_dev_list_lock stabilizes list membership, but it does not serialize the
per-device flags. During asynchronous controller setup, the worker can set
HCI_UNCONFIGURED and clear HCI_SETUP between the two passes. A controller
omitted from the allocation count can then become eligible for the fill
pass, causing an out-of-bounds write to rp->index[].

Allocate space for every device on hci_dev_list. Since list membership
cannot change while hci_dev_list_lock is held, the response remains large
enough regardless of flag transitions. The reported count and response
length still include only eligible unconfigured controllers.

Fixes: 73d1df2a7a ("Bluetooth: Add support for Read Unconfigured Index List command")
Cc: [email protected]
Signed-off-by: Aldo Ariel Panzardo <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-16 13:51:34 -04:00
Aldo Ariel Panzardo 6c78a213d9 Bluetooth: L2CAP: validate frame length before control and FCS access
l2cap_data_rcv() unpacks either a two-byte or four-byte control field
without first ensuring that it is present. A short ERTM or streaming-mode
frame can therefore cause an out-of-bounds read.

There is a second short-frame case when CRC16 is enabled. After the
control field is pulled, l2cap_check_fcs() subtracts two from skb->len
without checking it. If fewer than two bytes remain, the subtraction
wraps; skb_trim() leaves the buffer unchanged and the subsequent FCS
load reads past the logical end of the frame.

Validate that the frame contains both its control field and, when
enabled, its FCS before either field is accessed.

Fixes: 1c2acffb76 ("Bluetooth: Add initial support for ERTM packets transfers")
Fixes: fcc203c30d ("Bluetooth: Add support for FCS option to L2CAP")
Cc: [email protected]
Signed-off-by: Aldo Ariel Panzardo <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-16 13:51:34 -04:00
Aldo Ariel Panzardo 4c94557dd0 Bluetooth: ISO: balance the parent hold in hci_bind_bis()
hci_conn_link() takes a lifetime reference to its parent with
hci_conn_get(), but only takes an operational hold on the child.
hci_conn_unlink() later balances both a hold and a reference on the
parent.

The SCO and CIS paths pass a parent acquired from a connect helper, so
it already has a hold. For an additional BIS, hci_bind_bis() obtains the
parent from hci_conn_hash_lookup_big(), which returns a bare pointer.
Unlinking the child then drops the parent's existing hold and can
schedule it for disconnection while its socket is still using it.

Take a hold on the parent before linking it and drop that hold if linking
fails. A successful link transfers the hold to hci_conn_unlink().

Fixes: fa224d0c09 ("Bluetooth: ISO: Reassociate a socket with an active BIS")
Cc: [email protected]
Signed-off-by: Aldo Ariel Panzardo <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-16 13:51:34 -04:00
Aldo Ariel Panzardo b0a6cf99af Bluetooth: hci_sock: validate event length before filtering
is_filtered_packet() reads the event code from skb->data[0] without first
checking that the skb is nonempty. When an opcode filter is configured,
it also reads the command opcode at offsets 3 or 4 without checking that
a Command Complete or Command Status event is long enough.

hci_send_to_sock() invokes the filter before hci_event_packet() validates
the event header. A malformed event supplied by a controller or a vhci
device can therefore cause an out-of-bounds read.

Keep the unmasked event code for the opcode checks. The masked value is
needed for the 64-bit event bitmap, but using it to identify command events
aliases event codes above 0x3f. In particular, Synchronous Train Complete
(0x4f) was treated as Command Status (0x0f) even though its payload has no
opcode.

Reject actual command events that are too short for the field being
inspected. A truncated command event cannot match a configured opcode.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: [email protected]
Signed-off-by: Aldo Ariel Panzardo <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-16 13:51:34 -04:00
Aldo Ariel Panzardo e93fad891c Bluetooth: hci_sock: reject out-of-range OCF values
The raw HCI socket security filter has 128 OCF bits per supported OGF,
but masks the 10-bit OCF with 127 before looking up the command. An
unprivileged socket can therefore submit a reserved OCF that aliases an
allowlisted command modulo 128.

A conforming controller should reject reserved opcodes. Nevertheless,
the security decision must apply to the opcode that will actually be
sent, especially since controller-specific behavior is outside the host
stack's control.

Reject OCF values that cannot be represented by the security filter
instead of aliasing them onto an unrelated command.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: [email protected]
Signed-off-by: Aldo Ariel Panzardo <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-16 13:51:34 -04:00
Aldo Ariel Panzardo 0fcd4dad55 Bluetooth: ISO: release unused CIS holds after channel attach
hci_bind_cis() and hci_connect_cis() return one hci_conn hold for the
ISO layer.  A new channel association consumes that hold, which is
eventually released by iso_conn_free().

There are two cases where iso_chan_add() does not create an association:
it returns success when the socket is already attached to the same
iso_conn, and it returns -EBUSY when another socket is attached.  The
hold returned for the current call is unused in both cases.  This occurs
when deferred setup calls iso_connect_cis() again for its existing
socket, or when another socket attempts to reuse the CIS.

Detect the idempotent case while the connection is locked and release
the unused hold after iso_chan_add().  Also release it on -EBUSY.  Do not
drop it for other errors: a newly allocated iso_conn releases the
transferred hold when its last temporary reference is put.

Fixes: 69997d50ec ("Bluetooth: ISO: handle bound CIS cleanup via hci_conn")
Cc: [email protected]
Signed-off-by: Aldo Ariel Panzardo <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-16 13:51:34 -04:00
Aldo Ariel Panzardo e06d549fcd Bluetooth: hci_conn: fix CIS hold ownership on reuse
Commit 69997d50ec ("Bluetooth: ISO: handle bound CIS cleanup via
hci_conn") made hci_bind_cis() and hci_connect_cis() return a
connection with one hold for the ISO layer.  hci_bind_cis() currently
takes that hold only after configuring a CIS, so its BT_CONNECTED and
matching BT_BOUND paths return a bare lookup result.  Its configuration
failure path can likewise call hci_conn_drop() before taking a hold.

Take the hold before any state-dependent return or configuration error
so every successful return follows the documented ownership contract
and every error drop is balanced.

hci_connect_cis() also assumes hci_conn_link() always takes a new CIS
hold before dropping the one returned by hci_bind_cis().  However, the
helper returns an existing link without taking another hold.  In that
case, preserve the CIS hold for the caller and drop the redundant LE
hold because the existing link already owns its parent hold.  Returning
early also avoids changing an existing CIS back to BT_CONNECT.

Fixes: 69997d50ec ("Bluetooth: ISO: handle bound CIS cleanup via hci_conn")
Cc: [email protected]
Signed-off-by: Aldo Ariel Panzardo <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-16 13:51:33 -04:00
Lee Jones 71af682ba4 Bluetooth: mgmt: Dequeue pending mesh_send_sync entries on cancel
In send_cancel(), pending mesh_tx objects are removed from the
hdev->mesh_pending list and freed via mesh_send_complete().  However, if
a mesh transmission was already queued onto hdev->cmd_sync_work_list via
mesh_next(), the queued entry retains a raw pointer to mesh_tx.

When hci_cmd_sync_work later processes the entry, it attempts to execute
mesh_send_sync and its destroy callback mesh_send_start_complete using
the already freed mesh_tx pointer, leading to a use-after-free.

Fix this by invoking hci_cmd_sync_dequeue() for mesh_send_sync on the
target mesh_tx before completing it.  If the entry is found and dequeued,
its destroy callback will complete and free the object; otherwise,
mesh_send_complete() is called directly.

Additionally, ensure the transmission queue advances after cancellation
or errors.  In mesh_send_start_complete(), call mesh_next() on error
unless err is -ECANCELED, because hci_cmd_sync_dequeue() holds
hdev->cmd_sync_work_lock and calling mesh_next() synchronously would
deadlock.  Instead, advance the queue in send_cancel() once the lock is
released and if no transmission is in progress.

Fixes: b338d91703 ("Bluetooth: Implement support for Mesh")
Signed-off-by: Lee Jones <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-16 13:44:28 -04:00
Christiano Amora f033482d76 Bluetooth: SMP: reject Security Request over BR/EDR
Bose QC Ultra Headphones (dual-mode, same public address on both
transports) occasionally send an SMP Security Request on the BR/EDR
SMP fixed channel right after the ACL link is encrypted. The kernel
handles it as if it were an LE link: smp_cmd_security_req() has no
transport check, smp_ltk_encrypt() looks up an LTK with the ACL
connection's dst_type, and hci_find_ltk() matches the peer's LE LTK
because the LE public address type is stored as ADDR_LE_DEV_PUBLIC (0),
the same value as BDADDR_BREDR. HCI_OP_LE_START_ENC is then issued on
the ACL handle, the controller rejects it with Invalid HCI Command
Parameters, and hci_cs_le_start_enc() disconnects the link with
HCI_ERROR_AUTH_FAILURE. The headphones drop within a second of
connecting, before any profile is up; a manual reconnect works.

btmon (MediaTek MT7922, kernel 7.0.12):

  > HCI Event: Encryption Change (0x08) plen 4
        Status: Success (0x00)
        Handle: 50 Address: BC:87:FA:47:73:5E (Bose Corporation)
        Encryption: Enabled with AES-CCM (0x02)
  > ACL Data RX: Handle 50 flags 0x02 dlen 6
        BR/EDR SMP: Security Request (0x0b) len 1
        Authentication requirement: No bonding, No MITM, SC (0x08)
  < HCI Command: LE Start Encryption (0x08|0x0019) plen 28
        Handle: 50 Address: BC:87:FA:47:73:5E (Bose Corporation)
  > HCI Event: Command Status (0x0f) plen 4
        LE Start Encryption (0x08|0x0019) ncmd 1
        Status: Invalid HCI Command Parameters (0x12)
  < HCI Command: Disconnect (0x01|0x0006) plen 3
        Handle: 50 Address: BC:87:FA:47:73:5E (Bose Corporation)
        Reason: Authentication Failure (0x05)

SMP over BR/EDR is limited to cross-transport key derivation; the
Security Request procedure (Core Specification Vol 3, Part H, Section
2.4.6, PDU in Section 3.6.7) has no BR/EDR counterpart. Reply with
Pairing Failed / Command Not Supported on a non-LE link, before the PDU
is parsed, and keep the connection. The reply is sent directly rather
than through smp_failure(): rejecting a command on the wrong transport
is not an authentication failure, and MGMT_EV_AUTH_FAILED would make
bluetoothd disconnect the device.

Tested on the affected host (kernel 7.0.12, MediaTek MT7922, Bose QC
Ultra) with the patched module built out of tree: 7 days and 49
reconnects without a drop, against 2 drops in the 3 days before the
patch. Every disconnect in that week had a userspace or remote reason.

Fixes: b5ae344d4c ("Bluetooth: Add full SMP BR/EDR support")
Assisted-by: LLM
Signed-off-by: Christiano Amora <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-16 13:32:23 -04:00
Juan Perdomo 801fb950ca Bluetooth: RFCOMM: avoid socket lock inversion in listener cleanup
rfcomm_sock_cleanup_listen() closes unaccepted child sockets through
rfcomm_sock_close(), which takes the child socket lock before
rfcomm_dlc_close() acquires rfcomm_mutex. The RFCOMM worker takes these
locks in reverse order while handling connections and DLC state changes,
so lockdep reports a possible deadlock.

Close dequeued children without taking their socket lock. The accept queue
owns a reference to each child, and bt_accept_dequeue() locks the child
while unlinking it and clearing its parent pointer.

Dropping the child lock makes it important to prevent a concurrent
rfcomm_connect_ind() from enqueueing a new child after cleanup observes an
empty queue. Set a listening socket to BT_CLOSED while its lock is still
held, before dropping the lock and draining the queue. The state check in
rfcomm_connect_ind() then rejects new children once cleanup starts.

Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=0cece8fa7d83523f47a3
Fixes: b7ce436a5d ("Bluetooth: switch to lock_sock in RFCOMM")
Signed-off-by: Juan Perdomo <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-15 14:55:41 -04:00
Radek Podgorny 555cd2bd86 Bluetooth: keep dst_type with dst when reusing an LE connection
hci_connect_le() swaps the caller's identity address for the peer's
cached RPA when one is known, and stamps the matching
ADDR_LE_DEV_RANDOM on the local dst_type. On the conn-reuse path only
the address is copied into the connection:

  if (conn) {
          bacpy(&conn->dst, dst);

so conn->dst ends up holding an RPA while conn->dst_type still names the
identity it was resolved from, and hci_le_create_conn_sync() puts that
pair on air unchanged. An RPA declared as a public address is not
something any peer can answer.

Measured on a CYW43438 against a peer advertising an RPA the host holds
the IRK for, connecting to the identity address over a raw L2CAP socket.
The first attempt creates the connection, the second takes the reuse
path:

  LE Create Connection  3C:78:95:78:37:C3  type public
  LE Create Connection  5B:75:A2:26:D6:18  type public
  LE Connection Complete: Unknown Connection Identifier (0x02)

The second address is the peer's RPA. btmon annotates it with an OUI
lookup rather than "(Resolvable)" precisely because the command declares
it public; the same bit pattern annotates as resolvable once the type is
right.

The mistyped pair is also why nothing downstream repairs it.
hci_bdaddr_is_rpa() tests the type before the address, so an RPA carrying
a public type is not recognised as one, and hci_find_irk_by_addr() then
searches for an identity address that does not match it either.

Copy the type along with the address.

The assignment used to be unconditional just below this block and covered
both paths; it moved into hci_conn_add_unset(), which the reuse path does
not go through.

Cc: [email protected]
Fixes: 14b06c3a88 ("Bluetooth: HCI: Always use the identity address when initializing a connection")
Assisted-by: Claude:claude-opus-5
Signed-off-by: Radek Podgorny <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-15 14:55:32 -04:00
Luiz Augusto von Dentz 296e7f3c50 Bluetooth: ISO: set BT_LISTEN before requesting a BIG sync
A BIS connection is matched to its parent socket by looking for a
socket in BT_LISTEN state with the same BIG handle:

  iso_conn_ready()
    if (test_bit(HCI_CONN_BIG_SYNC, &hcon->flags))
            parent = iso_get_sock(hdev, &hcon->src, &hcon->dst,
                                  BT_LISTEN, iso_match_big_hcon, hcon);

The socket was only moved to BT_LISTEN after iso_conn_big_sync()
returned, while the LE BIG Create Sync command has already been queued
by then. If the BIG sync is established before the state is updated,
which is easy to hit with an emulated controller as the command may
complete in a few hundred microseconds, no parent is found and the BIS
connections are never notified to the listening socket.

The user space is then left waiting for connections that never arrive,
e.g. bluetoothd never completes a MediaTransport1.Acquire of a
Broadcast Sink transport.

Move the socket to BT_LISTEN before requesting the BIG sync, so the
state is visible by the time the command is queued, and restore the
previous state if the request could not be started. Since the socket is
briefly visible as a listening socket, child sockets may have been
queued in the meantime, so drain the accept queue before restoring the
state: the cleanup paths of BT_CONNECT2/BT_CONNECTED don't do it and the
children would be left with a dangling parent pointer.

Fixes: fbdc4bc472 ("Bluetooth: ISO: Use defer setup to separate PA sync and BIG sync")
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-15 14:53:12 -04:00
Luiz Augusto von Dentz ca18ee413a Bluetooth: ISO: Fix parent socket leak in iso_conn_ready()
iso_get_sock() returns the parent socket with a reference held, which is
dropped by sock_put() once the child socket has been set up. The error
path taken when iso_sock_alloc() fails only calls release_sock() and
returns, leaking the reference and thus the parent socket itself.

Drop the reference on that path as well.

Fixes: fa224d0c09 ("Bluetooth: ISO: Reassociate a socket with an active BIS")
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-15 14:53:03 -04:00
Chengfeng Ye 9a10987a2f Bluetooth: hci_sync: Serialize local codec list cleanup
hci_dev_close_sync() clears hdev->local_codecs after releasing hdev->lock.
Codec list additions and both traversals in sco_sock_getsockopt() use that
lock, but the close path does not. A close and BT_CODEC query can therefore
interleave as follows:

  hci_dev_close_sync()          sco_sock_getsockopt()
                                hci_dev_lock()
                                fetch codec entry
  hci_codec_list_clear()
    kfree(entry)
                                read entry->id

The reader then accesses an entry which the close path has freed. KASAN
reported:

  BUG: KASAN: slab-use-after-free in sco_sock_getsockopt+0xfa0/0xfe0
  Read of size 1 at addr ffff8881001c3450
  Call Trace:
   sco_sock_getsockopt+0xfa0/0xfe0
   do_sock_getsockopt+0x537/0x7b0
   __sys_getsockopt+0xf2/0x170
  Allocated by task 92:
   hci_codec_list_add.isra.0+0x2c/0x440
   hci_read_codec_capabilities+0x224/0x590
   hci_read_supported_codecs+0x2c2/0x640
  Freed by task 92:
   kfree+0x131/0x3c0
   hci_codec_list_clear+0xd8/0x160
   hci_dev_close_sync+0x92a/0xfa0

Take hdev->lock around the clear operation at its existing point in the
close path. This makes the clear wait for active readers and prevents a new
traversal until the list is empty without changing teardown ordering.

Fixes: b938790e70 ("Bluetooth: hci_codec: Fix leaking content of local_codecs")
Cc: [email protected]
Signed-off-by: Chengfeng Ye <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-15 14:52:31 -04:00
Laxman Acharya Padhya d0795cfd6f Bluetooth: hci_codec: validate vendor codec count length
The Read Local Supported Codecs parsers consume the variable-sized
standard codec array before parsing the vendor codec count.  Although the
initial reply-size check includes a vendor count byte in the fixed layout,
it does not guarantee that the byte remains after the standard codec array.

If a controller reply ends immediately after that array, calculating the
vendor codec array size reads vnd_codecs->num beyond the skb data.  Use
skb_pull_data() to validate and consume each codec header before using its
count in both command variants.

Fixes: 8961987f3f ("Bluetooth: Enumerate local supported codec and cache details")
Fixes: 9ae664028a ("Bluetooth: Add support for Read Local Supported Codecs V2")
Cc: [email protected]
Suggested-by: Luiz Augusto von Dentz <[email protected]>
Signed-off-by: Laxman Acharya Padhya <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-15 14:52:12 -04:00
Radek Podgorny 4914c49989 Bluetooth: put the peer's on-air address on air when we cannot resolve
An identity address only reaches a peer that is advertising an RPA if the
controller resolves it on our behalf. Where it cannot, the host has to put
the peer's on-air address on air itself.

hci_connect_le() still swaps the caller's identity address for the peer's
cached RPA before creating the connection, but __hci_conn_add() resolves
the RPA back to the identity address when it stores it, so the identity is
what goes out. Storing the identity is right when the controller
translates it on the way to the radio; without LL Privacy, or with this
peer absent from the resolving list, nothing does.

A peer advertising an RPA cannot answer its identity address, so the
attempt burns a full create-connection timeout. That is not merely a slow
connect: a controller without extended scanning cannot scan while it is
initiating, so every dead attempt also takes the scanner off the air for
the whole timeout.

Measured on a CYW43438, which reports neither LL Privacy nor extended
advertising (LE features 3f 00 00 08 00 00 00 00), against a peer
advertising a resolvable private address the host holds the IRK for, with
the connection requested on the peer's identity address:

  before: LE Create Connection to the identity address, public type
          1.61s -> 22.07s, then LE Create Connection Cancel
          LE Connection Complete: Unknown Connection Identifier (0x02)
  after:  LE Create Connection to the peer's RPA, random type
          LE Connection Complete: Success

Advertising reports reaching the host per second, same window, same five
unrelated devices on the adapter:

  before   1s:2   [nothing from 2s through 21s]   22s:5  23s:3
  after    0s:11 1s:5 2s:2 3s:5 4s:3 5s:4 ... 21s:2 22s:1 23s:2

One dead connect costs twenty seconds of scanning for every device on the
adapter, not just the one being dialled.

Keep the RPA in conn->dst unless the controller will translate the
identity address: address resolution enabled and the peer's identity
actually programmed into the resolving list. Testing ll_privacy_capable()
alone would not be enough: it reports the feature bit, not whether
resolution is switched on and not whether this peer is in the list.
Resolution is cleared with the other volatile flags on power-off and
switched off again while suspend pauses scanning, and a peer's IRK is only
programmed along the accept list path, so a direct-connect target, a peer
without HCI_CONN_FLAG_ADDRESS_RESOLUTION, and one that did not fit in a
full list are all absent from it.

With the peer programmed, the identity address stays in conn->dst and the
controller translates it: measured on an Intel controller, the host dials
the identity and LE Enhanced Connection Complete reports Resolved Public
with the peer's RPA in the separate peer resolvable private address field.
With the peer absent from the list the same setup dials the RPA itself.

Everything downstream already copes with an RPA in conn->dst: it is what
every outgoing LE connection stored before 14b06c3a88, the connection
complete event names the address that was dialled, and
le_conn_complete_evt() resolves it back to the identity once the link is
up. ISO links keep the unconditional conversion: they are created from an
existing ACL or a periodic sync and never dial this address themselves.

Keeping the RPA is only right while the peer is still using it, which is
why the preceding patch drops the cached RPA as soon as the peer is seen
advertising its identity address. Without that, a peer that turns privacy
off would be dialled on the address it abandoned rather than the one it
is answering on.

Fixes: 14b06c3a88 ("Bluetooth: HCI: Always use the identity address when initializing a connection")
Assisted-by: Claude:claude-opus-5
Assisted-by: Claude:claude-fable-5
Signed-off-by: Radek Podgorny <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-15 14:50:25 -04:00
Weiming Shi d236517c26 Bluetooth: coredump: Quiesce dump work on unregister
hci_devcd_handle_pkt_init() arms dump_timeout and coredump producers
queue dump_rx without holding an hdev reference. Unregister leaves both
works live, so disconnecting during an active dump lets them access hdev
after hci_release_dev() frees it.

Shut down coredump processing during unregister. Close the producer gate
under dump_q.lock before disabling both works, then free the active buffer
and queued packets under hci_dev_lock. Serializing the gate with enqueue
prevents controller-specific workers from adding packets after the final
purge.

Fixes: 9695ef876f ("Bluetooth: Add support for hci devcoredump")
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=b170dbf55520ebf5969a
Reported-by: Aby Sam Ross <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Suggested-by: Aby Sam Ross <[email protected]>
Reported-by: Tristan Madani <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reported-by: Xiang Mei <[email protected]>
Assisted-by: OpenAI Codex:gpt-5
Signed-off-by: Weiming Shi <[email protected]>
Reported-by: Xiang Mei <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-15 14:49:41 -04:00
ThangNN99 6610c6fe4b Bluetooth: hci_core: Fix queuing tx_work after workqueue is drained
hci_send_acl(), hci_send_sco() and hci_send_iso() queue hdev->tx_work
unconditionally. They can run from the L2CAP/SCO/ISO socket send path
while hci_dev_close_sync() is draining hdev->workqueue (HCIDEVDOWN
racing with a socket write). Since that queue_work() is not chained
work from the tx_work worker itself, __queue_work() sees the queue
marked __WQ_DRAINING, warns "cannot queue %ps on wq %s", and drops
the work:

  WARNING: CPU: 1 PID: 5985 at kernel/workqueue.c:2352 __queue_work
  Call Trace:
   queue_work_on
   l2cap_chan_send
   l2cap_sock_sendmsg
   ...

hci_dev_close_sync() already sets HCI_CMD_DRAIN_WORKQUEUE before
draining, but only hci_cmd_work() and handle_cmd_cnt_and_timer()
check it before queuing. Route the tx_work producers through the
same guard via a shared hci_sched_tx() helper.

Fixes: 525daaea45 ("Bluetooth: hci_sync: Set HCI_CMD_DRAIN_WORKQUEUE during device close")
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=b6919040d9958e2fc1ae
Signed-off-by: ThangNN99 <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-15 14:48:44 -04:00
Aamir Ahmed e824176679 Bluetooth: eir: validate service data length before reading UUID
eir_get_service_data() reads a 16-bit UUID from the service data using
get_unaligned_le16() without first checking that the data is long enough
to hold a UUID16 (2 bytes). If a malformed EIR entry has a service data
field with only 1 byte of payload (field_len=2), eir_get_data() returns
dlen=1. The subsequent get_unaligned_le16() then reads 1 byte past the
field boundary.

Additionally, if the corrupted UUID happens to match, the length
calculation "dlen - 2" underflows to SIZE_MAX since dlen is size_t.
Current callers either pass NULL for the length parameter or bounds-check
the returned length, but future callers may not.

Add a check that dlen >= sizeof(u16) and skip fields that are too short
to contain a valid UUID16.

Fixes: 8f9ae5b3ae ("Bluetooth: eir: Add helpers for managing service data")
Cc: [email protected]
Signed-off-by: Aamir Ahmed <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-15 14:30:14 -04:00
Linus Torvalds 7844502343 Merge tag 'net-7.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
 "Nothing too exciting, usual stream of fixes. Including fixes from
  Netfilter, Bluetooth and WPAN.

  Current release - new code bugs:

   - Bluetooth: hci_sync: fix not setting CE length properly

   - eth: enic: match mailbox replies to request numbers

  Previous releases - regressions:

   - tunnels: drop stale dst when building an ICMP error for PMTUD

   - ipv6: null-check fib6_node before accessing in __ip6_del_rt_siblings()
     (bug in the rtnl_lock -> RCU conversion)

   - eth: bnxt_en:
       - fix crashes on Thor2 due to OOB coalescing buffer accesses
       - prevent queue stop with deferred completions

  Previous releases - always broken:

   - eth:
       - ice: don't dereference pointers from TP_printk()
       - fix OOB writes on ethtool flow rule dump in 3 drivers
       - mlx5: fix FEC configuration with RS_544_514_INTERLEAVED_QUAD

   - dsa: tag_brcm: legacy FCS: request needed tailroom

  Misc:

   - net: cap tx_queue_len at S16_MAX to prevent oversized ring alloc

   - ipv6: flowlabel: cap duplicate leases per socket"

* tag 'net-7.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (164 commits)
  selftests: tc-testing: test action batch failure cleanup
  net/sched: act_api: release all action references on NEWACTION failure
  openvswitch: fix wrong flag value in get_ipv6_ext_hdrs()
  ipmr: account multicast table and route memory
  net: phy: dp83td510: handle the active-high LED polarity mode
  net: macb: initialize PTP state before registering clock
  net: hsr: enable promiscuous mode on interlink port with fwd offload
  ipv6: fix fib6 walker UAF on seq stop
  net: stmmac: fix TX descriptor availability check for TSO traffic
  net/rds: fix tcp stream corruption with large pages
  net: mana: restore the XDP program pointer when pre-allocation fails
  net: phy: dp83867: handle the active-high LED polarity mode
  octeontx2-af: fix PF/CGX debugfs PCI bus lookup
  net: net_failover: Fix the deadlock in net_failover_slave_name_change()
  net: phy: mediatek-ge: disable EEE on the MT7530 PHY
  tcp: reject non zerocopy devmem tx
  net: ethernet: mtk_eth_soc: populate lpi_interfaces to fix EEE support
  net: dsa: mt7530: populate lpi_interfaces to fix EEE support
  net: hinic: fix mailbox segment buffer overflow
  net: sun4i-emac: fix missing of_node_put() for phy_node
  ...
2026-09-10 14:07:48 -07:00
Krystian Kaniewski 9b851b09b3 Bluetooth: hci_sysfs: Fix NULL pointer dereference in device_del()
A NULL pointer dereference in klist_put() occurs when a child device (such
as a BNEP network device in bnep_session) is concurrently being
unregistered while hci_conn_del_sysfs() reparents child devices.

This is caused by a race condition between hci_conn_del_sysfs() and
concurrent child device unregistration (e.g. bnep_session calling
unregister_netdev()). During device unregistration, device_del() snapshots
a non-NULL parent pointer. Concurrently, hci_conn_del_sysfs() finds the
child device using device_find_any_child() and calls device_move() to
reparent it to NULL, which removes the node from its parent's klist and
clears knode_parent. Subsequently, device_del() calls
klist_del(&dev->p->knode_parent) using the stale parent snapshot, causing
klist_put() to dereference knode_klist(n)->put on an already removed node,
resulting in a NULL pointer dereference.

This race was introduced by commit 27aabf27fd ("Bluetooth: fix
use-after-free in device_for_each_child()"), which replaced
device_find_child(..., __match_tty) with device_find_any_child() in
hci_conn_del_sysfs(). That change was intended to avoid a use-after-free
where conn->dev outlived its parent hdev->dev when child devices held
references to conn->dev, because conn->dev only held a reference to
hdev->dev while registered in sysfs.

Fix the issue properly by taking an explicit reference to the parent device
with get_device(&hdev->dev) in hci_conn_init_sysfs() and dropping it with
put_device(parent) in bt_link_release() when the conn device is freed. This
ensures that hdev->dev remains valid for the entire lifecycle of conn->dev,
resolving the underlying use-after-free. With the parent reference held
properly, restore the __match_tty filter in hci_conn_del_sysfs() so that
device_move() is only invoked on persistent RFCOMM TTY devices as
originally intended, eliminating the race condition with unregistering
network devices.

Fixes: 27aabf27fd ("Bluetooth: fix use-after-free in device_for_each_child()")
Assisted-by: Gemini:gemini-3.7-flash syzbot
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=6df45dd3d03e1a9aca96
Link: https://syzkaller.appspot.com/ai_job?id=f1c0e740-db21-40af-a9ff-84db0fd8b8bd
Signed-off-by: Krystian Kaniewski <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-08 17:12:45 -04:00
Luiz Augusto von Dentz 3621f78d43 Bluetooth: hci_sync: Fix not setting CE length properly
Both hci_le_set_def_rate_sync() and hci_le_conn_rate_request_sync() were
leaving Min_CE_Length and Max_CE_Length set to 0x0000, but the connection
event length recommended in requests by a Peripheral has a valid range of
0x0001 to 0x7CFF (Time = N * 125 us, Time Range: 0.125 ms to 3.999875 s),
so 0x0000 cannot be used.

Set both to the minimum valid value, which is safe since the Controller
is not required to use these values:

BLUETOOTH CORE SPECIFICATION Version 6.2 | Vol 4, Part E
7.8.157. LE Connection Rate Request command
7.8.158. LE Set Default Rate Parameters command

The Min_CE_Length and Max_CE_Length parameters provide the Controller
with the expected minimum and maximum length of the connection events.
The Controller is not required to use these values.

Fixes: 2f8784cfe8 ("Bluetooth: Add support for Shorter Connection Interval (SCI) feature")
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-09-08 17:11:05 -04:00
Kees Cook 3a2c4d55e3 treewide: refresh kmalloc_obj() conversions
This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci

This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.

Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.

Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <[email protected]>
2026-09-04 21:37:00 -07:00
Pauli Virtanen 0d77683237 Bluetooth: L2CAP: clear FLAG_DEFER_SETUP only for same PID/PSM
l2cap_ecred_defer_connect() clears FLAG_DEFER_SETUP also for channels
with different PID/PSM, which will not be added to the same
ECRED_CONN_REQ in any case. Consequently, only one ECRED connection
group can work at a time although it appears intended they would be
separate for each PID/PSM combination.

Fix by clearing FLAG_DEFER_SETUP only for the connections that could be
added in the request. Retain test_bit(FLAG_DEFER_SETUP) before calling
get_peer_pid as it may be NULL otherwise.

Fixes: da49b602f7 ("Bluetooth: L2CAP: Use DEFER_SETUP to group ECRED connections")
Signed-off-by: Pauli Virtanen <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-08-31 13:59:45 -04:00
Pauli Virtanen 56c2b5831d Bluetooth: L2CAP: fix out-of-bounds write in l2cap_ecred_connect
l2cap_chan_connect() tries to ensure there are no more than
L2CAP_ECRED_CONN_SCID_MAX pending ECRED channels, so they fit in the
same L2CAP_ECRED_CONN_REQ that l2cap_ecred_connect() constructs.

However, the check only counts deferred channels.  If 6 L2CAP sockets
are connected at the same time in order DDDDND (D=deferred,
N=non-deferred), the last can bump the total to max+1.  It results to
one __le16 written out of bounds of the scid array, and an invalid
ECRED_CONN_REQ being sent.

Fix by leaving room for the non-deferred pending ECRED channels in the
counting in l2cap_chan_connect(), so the limit can't be exceeded.

Move counting under same critical section where the channel is added.
Although race conditions involving this appear unreachable, it's easier
to see.

Also add WARN_ON_ONCE check in l2cap_ecred_defer_connect() to make this
less brittle.

Fixes: da49b602f7 ("Bluetooth: L2CAP: Use DEFER_SETUP to group ECRED connections")
Signed-off-by: Pauli Virtanen <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-08-31 13:57:52 -04:00
Pauli Virtanen 4ef05db5b0 Bluetooth: L2CAP: fix chan mode for LE_CONN_REQ + EXT_FLOWCTL pchan
l2cap_new_connection() sets default value of channel mode to match the
parent channel.  l2cap_le_connect_req() left this at the default, and
created L2CAP_MODE_EXT_FLOWCTL channels if listening pchan has that
mode.  This causes FLAG_DEFER_SETUP channels to reply to
L2CAP_LE_CONN_REQ with L2CAP_ECRED_CONN_RSP, which is incorrect.

It can also result to stack OOB write (of l2cap_alloc_cid determined
values) in l2cap_ecred_rsp_defer(), as l2cap_le_connect_req() does not
limit maximum number of deferred channels or check for duplicate ident.

Fix by setting chan->mode correctly in l2cap_le_connect_req().

Also check channel mode in l2cap_ecred_rsp_defer(), and do WARN_ON_ONCE
instead of OOB write to make it less brittle.

Fixes: 15f02b9105 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode")
Signed-off-by: Pauli Virtanen <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-08-31 13:53:32 -04:00
Aleksandr Nogikh 57938bbdb9 Bluetooth: hci_core: Fix race condition during device registration
In hci_register_dev(), the power_on work item is queued to
hdev->req_workqueue before initializing hdev->adv_monitors_idr and
registering the MSFT extension via msft_register(). For devices marked with
quirks such as HCI_QUIRK_RAW_DEVICE, the HCI_UNCONFIGURED flag is set on
the device. When the power_on work item runs concurrently on another CPU,
hci_power_on() detects that the device is unconfigured and immediately
invokes hci_dev_do_close(), which calls msft_do_close().

Concurrently, msft_register() allocates the msft structure and exposes it
to hdev->msft_data prior to calling mutex_init(&msft->filter_lock). If
msft_do_close() executes while hdev->msft_data is already assigned but the
mutex has not yet been initialized, mutex_lock(&msft->filter_lock) operates
on an uninitialized mutex, triggering a DEBUG_LOCKS warning:

DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: kernel/locking/mutex.c:625 at __mutex_lock_common
kernel/locking/mutex.c:625 [inline]
WARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x12d8/0x1550
kernel/locking/mutex.c:821
...
Call Trace:
 <TASK>
 msft_do_close+0x308/0x7b0 net/bluetooth/msft.c:693
 hci_dev_close_sync+0x86b/0x10a0 net/bluetooth/hci_sync.c:5522
 hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]
 hci_power_on+0x32c/0x750 net/bluetooth/hci_core.c:937
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
 worker_thread+0x92d/0xe10 kernel/workqueue.c:3486
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Fix this by moving the queue_work() call in hci_register_dev() to after
idr_init(&hdev->adv_monitors_idr) and msft_register(hdev) so that device
structures and extensions are fully initialized before asynchronous tasks
can access them. Additionally, assign hdev->msft_data in msft_register()
only after mutex_init(&msft->filter_lock) has completed.

Fixes: 9e14606d8f ("Bluetooth: msft: Extended monitor tracking by address filter")
Assisted-by: Gemini:gemini-3.7-flash Gemini:gemini-3.1-pro-preview syzbot
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=14ce1b05b7d5a989abbe
Link: https://syzkaller.appspot.com/ai_job?id=2bc9e8aa-ca6d-43e2-be2c-fd5d9f649d7e
Signed-off-by: Aleksandr Nogikh <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-08-31 13:52:54 -04:00
Chengfeng Ye ebe6674292 Bluetooth: RFCOMM: serialize session teardown
rfcomm_kill_listener() walks session_list and deletes every session
without holding rfcomm_mutex, unlike the normal session processing and
connect error paths.

Under normal operation, an open RFCOMM socket pins rfcomm.ko, so
rfcomm_kill_listener() does not run concurrently with rfcomm_dlc_open().
However, forced module unload via delete_module(O_TRUNC) can stop
krfcommd while a failed connect is still unwinding.

  connect task                    forced unload / krfcommd
  ------------                    ------------------------
  rfcomm_lock()
  rfcomm_session_add()
                                  delete_module("rfcomm", O_TRUNC)
                                  rfcomm_kill_listener()
                                    fetch session from session_list
  kernel_connect() fails
  rfcomm_session_del()
    remove and free session
                                  rfcomm_session_del(session)

The final call then reads the freed session and may corrupt the list.

KASAN reported with mdelay() to enlarge critical window:

  BUG: KASAN: slab-use-after-free in rfcomm_run+0x3802/0x3f00 [rfcomm]
  Read of size 8 at addr ffff888111058d40 by task krfcommd/79
  Tainted: [R]=FORCED_RMMOD
  Allocated by task 86:
   rfcomm_session_add+0xa1/0x300 [rfcomm]
   rfcomm_dlc_open+0x8b2/0xf30 [rfcomm]
   rfcomm_sock_connect+0x34c/0x530 [rfcomm]
  Freed by task 86:
   kfree+0x121/0x3c0
   rfcomm_dlc_open+0xab7/0xf30 [rfcomm]
   rfcomm_sock_connect+0x34c/0x530 [rfcomm]

Hold rfcomm_mutex across the teardown traversal so every reachable
session_list walk uses the same serialization.

Reviewed-by: Ali Ahmet Memis <[email protected]>
Tested-by: Ali Ahmet Memis <[email protected]>
Reviewed-by: Pauli Virtanen <[email protected]>
Signed-off-by: Chengfeng Ye <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-08-24 13:14:43 -04:00
Radek Podgorny 7e1e404720 Bluetooth: do not leak an hci_conn when a second LE connect is rejected
create_le_conn_complete() decides whether the failed connection is
still pending by comparing it against hci_lookup_le_connect(), which
returns the first LE connection in BT_CONNECT. That is the same
connection only while at most one is pending.

Two can be pending. Connections created on the passive scan path sit
in BT_CONNECT with HCI_CONN_SCANNING set and are invisible to
hci_lookup_le_connect() until hci_le_create_conn_sync() clears the
flag when their command is issued, so the -EBUSY guard in
hci_connect_le() does not prevent a second connection from being
queued while the first is still on the scan path. Whenever two
connections are in BT_CONNECT at once, the lookup may return one
connection while create_le_conn_complete() is reporting the failure
of the other; the early exit then drops the error and hci_conn_failed()
never runs on the connection that failed.

The controller also rejects a second HCI_OP_LE_CREATE_CONN issued
while another connection creation is still outstanding, per Core Spec
Vol 4, Part E. The spec calls for Command Disallowed there; the
bcm43438 observed here answers with an LMP/LL error code instead,
which bt_to_errno() maps to the -EPROTO (-71) in the log below.

The leaked connection stays in BT_CONNECT forever, and because
hci_connect_le() refuses to dial while hci_lookup_le_connect() finds
anything, every subsequent attempt to reach any peer fails with
-EBUSY and no command reaches the controller at all.

Seen on a bcm43438 with two BLE peers polled on the same interval
(state 5 is BT_CONNECT; both handles are UNSET ones, allocated from
the ida above HCI_CONN_HANDLE_MAX):

  Bluetooth: hci1: Opcode 0x2013 failed: -71

  # hcitool con
          < LE 14:9C:EF:03:68:81 handle 3840 state 5 lm CENTRAL
          < LE C4:D3:6A:8C:B5:38 handle 3841 state 5 lm CENTRAL

A btmon capture across the next ten minutes of connect attempts
contains no HCI_OP_LE_CREATE_CONN at all; outgoing LE connections
do not recover until the adapter is reset. With this change the same
scenario fails the rejected connection cleanly and further connects
to both peers go through.

Ask about the connection itself instead of about the device.

Fixes: c9f73a2178 ("Bluetooth: hci_conn: Fix hci_connect_le_sync")
Signed-off-by: Radek Podgorny <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-08-24 13:14:35 -04:00
Chengfeng Ye 759c185d0b Bluetooth: RFCOMM: serialize security confirmation handling
rfcomm_security_cfm() looks up a session on session_list and then walks
its DLC list without holding rfcomm_mutex. Since RFCOMM session teardown
uses rfcomm_mutex, krfcommd can close and free the same session and DLCs
concurrently:

  hci_rx_work                    krfcommd
  -----------                    ---------
  rfcomm_session_get()
                                 rfcomm_lock()
                                 rfcomm_session_close()
                                   rfcomm_dlc_unlink()
                                   rfcomm_session_del()
                                     kfree(s)
                                 rfcomm_unlock()
  walk s->dlcs

The callback can then read a freed session list head and touch freed DLCs
while updating their flags or timers.

Serialize the session lookup and DLC traversal in rfcomm_security_cfm()
with rfcomm_mutex. This matches the existing RFCOMM session lifetime
rules and prevents concurrent rfcomm_session_del() / rfcomm_dlc_unlink()
from tearing the objects down while the callback is using them.

KASAN reported:

  BUG: KASAN: slab-use-after-free in rfcomm_security_cfm+0x41c/0x440
  Read of size 8 at addr ffff888111fb3960 by task kworker/u17:1/89
  Workqueue: hci0 hci_rx_work
  Call Trace:
   rfcomm_security_cfm+0x41c/0x440
   hci_encrypt_cfm+0x139/0x590
   hci_encrypt_change_evt+0x37b/0xc40
   hci_event_packet+0x71b/0xb20
   hci_rx_work+0x293/0x730
  Allocated by task 69:
   rfcomm_session_add+0x9e/0x2f0
   rfcomm_run+0x44b/0x41e0
  Freed by task 69:
   kfree+0x131/0x3c0
   rfcomm_session_del+0x188/0x220
   rfcomm_run+0x1985/0x41e0

Fixes: 08c30aca9e ("Bluetooth: Remove RFCOMM session refcnt")
Cc: [email protected]
Signed-off-by: Chengfeng Ye <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-08-24 13:13:36 -04:00
Hyunwoo Kim 44c98fd082 Bluetooth: RFCOMM: Validate MTU in rfcomm_apply_pn() to prevent infinite loop
rfcomm_apply_pn() accepts the MTU value from a remote PN (Parameter
Negotiation) frame without checking for zero. When the remote peer
sends an MTU of zero, d->mtu is set to 0. This causes the sendmsg
path to enter an infinite loop when fragmenting data, as each fragment
has size == min_t(size_t, len, 0) == 0, so the remaining length never
decreases. The infinite allocation of zero-length skbs exhausts all
system memory.

Fix by clamping d->mtu to RFCOMM_DEFAULT_MTU when the negotiated
value is zero, consistent with the initial value assigned in
rfcomm_dlc_alloc().

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Hyunwoo Kim <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-08-24 13:13:13 -04:00
Hang Nan 560bef609f Bluetooth: ISO: fix use-after-free of listener socket in iso_conn_ready
iso_conn_ready() looks up the BIS listener socket with iso_get_sock(),
which takes a reference, and then, without re-checking its state,
creates a child socket from it:

    parent = iso_get_sock(hdev, ...);
    if (!parent)
        return;

    lock_sock(parent);
    sk = iso_sock_alloc(sock_net(parent), NULL, BTPROTO_ISO, ...);
    ...
    iso_chan_add(conn, sk, parent);
    ...
    release_sock(parent);
    sock_put(parent);

If the listener socket is closed concurrently, between iso_get_sock()
and lock_sock(), the reference taken by iso_get_sock() may be the last
one: the close path drops the link-list reference, and once
iso_conn_ready() drops its own reference at the end of the function the
socket is freed.  The child socket, however, is already linked to the
freed parent, and a later disconnect of the child runs iso_chan_del()
-> bt_accept_unlink(), which dereferences the dangling parent pointer
into the freed accept queue (a use-after-free).  The same dangling
pointer is also dereferenced through parent->***() in
iso_chan_del().

Fix it the same way the connected (non-BIS) path was fixed in commit
0d255e63fc ("Bluetooth: ISO: hold sk properly in iso_conn_ready"):
after taking the socket lock, re-check that the parent is still a
listening, alive socket, and bail out otherwise.

Fixes: ccf74f2390 ("Bluetooth: Add BTPROTO_ISO socket type")
Cc: [email protected]
Signed-off-by: Hang Nan <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-08-24 13:13:06 -04:00
Xin Chen f5afdff569 Bluetooth: hci_core: use skb_get() instead of skb_clone() for req_skb
BT enable fails intermittently with -ETIMEDOUT (-110).  The kernel log
shows the HCI Read Local Version command was sent and the firmware
replied with status 0x00 (logged by hci_req_cmd_complete() BT_DBG),
but the waiter in __hci_cmd_sync_sk() never woke up and timed out
after 10 s:

  bluetooth hci0: Opcode 0xfc00              // __hci_cmd_sync_sk
  bluetooth hci0: opcode 0xfc00 plen 1       // hci_cmd_sync_add
  bluetooth hci0: skb len 4                  // hci_cmd_sync_alloc
  bluetooth hci0: length 1                   // hci_req_sync_run
  Bluetooth: hci0 cmd_cnt 1 cmd queued 1     // hci_cmd_work
  Bluetooth: hci0 type 1 len 4               // hci_send_frame
  Bluetooth: opcode 0xfc00 status 0x00       // hci_req_cmd_complete
  <-- req_skb NULL: req_complete_skb not set,
      hci_cmd_sync_complete() never called,
      req_status stays HCI_REQ_PEND            -->
  <-- 10 s later: wait_event_interruptible_timeout expires -->
  bluetooth hci0: end: err -110              // __hci_cmd_sync_sk

The root cause is that hci_send_cmd_sync() clones the sent command
into hdev->req_skb so that hci_req_cmd_complete() can locate the
registered completion callback.  Under memory pressure this
skb_clone() fails, leaving hdev->req_skb NULL.  The firmware reply
is received and processed, but hci_req_cmd_complete() finds NULL
req_skb, so hci_cmd_sync_complete() is never called, req_status
stays HCI_REQ_PEND, and the waiter times out with -ETIMEDOUT.

req_skb is only used to read bt_cb(skb)->hci callbacks and opcode --
it is never modified.  Replace skb_clone() with skb_get(), which
simply increments the reference count of hdev->sent_cmd without
allocating new memory and therefore cannot fail.

This issue was first observed as a use-after-free in ttyport_close()
when ttyport_open() failed, which was investigated in an earlier
patch series [1].  That investigation led to the discovery of the
true root cause described above.

[1] https://lore.kernel.org/all/[email protected]/

Fixes: 2615fd9a7c ("Bluetooth: hci_sync: Fix overwriting request callback")
Cc: [email protected]
Signed-off-by: Xin Chen <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-08-24 13:11:55 -04:00
Valentin Kindschi 941929abe5 Bluetooth: hci_event: clear HCI_LE_ADV only on a created connection
le_conn_complete_evt() clears HCI_LE_ADV before looking at the event
status, on the premise stated in its comment that all controllers stop
advertising when a connection is created.

That premise only holds when a connection was actually created. On a
non-zero status none was, and the controller is still advertising: after
the host issues LE Create Connection Cancel the event arrives with
Unknown Connection Identifier (0x02), and a connection timeout behaves
the same way. Clearing the flag there leaves the host believing
advertising is off while the controller has it on.

It is also wrong for extended advertising, where several sets can be
advertising at once. hci_cc_le_set_ext_adv_enable() is careful about
this - on disabling one set it walks hdev->adv_instances and only clears
HCI_LE_ADV once no instance is still enabled. The unconditional clear
here discards that bookkeeping, so one set connecting drops the flag
while the others keep advertising.

The direction of the error matters. A flag left set is self-correcting:
hci_disable_advertising_sync() sends LE Set Advertising Enable(0) and
the command complete puts the state back. A flag left clear is not,
because that same function returns early without sending anything while
the flag is clear:

  - LE Set Advertising Parameters is then sent to a controller that is
    still advertising, and is correctly rejected with Command Disallowed
    (0x0c);
  - hci_enable_advertising_sync() returns at that point, before the
    LE Set Advertising Enable that would set HCI_LE_ADV again.

On a controller without LE Extended Advertising that is reachable from
here: hci_schedule_adv_instance_sync() re-arms adv_instance_expire every
HCI_DEFAULT_ADV_DURATION (2 s) and its "already advertising" shortcut
tests HCI_LE_ADV, which can no longer become true, so the parameter
write is retried for as long as advertising is configured:

  Bluetooth: hci0: Opcode 0x2006 failed: -16

Only clear the flag when a connection was established.

Note this is not on its own sufficient to stop that retry loop - the
redundant enable queued by hci_le_conn_failed() clears HCI_LE_ADV itself
and recreates the same mismatch, which patch 1 addresses. This patch
fixes the event handler reporting a state the controller is not in.

Verified on the affected device (BCM43455, legacy advertising only) with
this patch and patch 1 applied. A 221 s btmon capture with an out-of-range
peer at -90 dBm contains two outgoing connection attempts that the host
cancelled, each producing exactly the event this patch changes:

  < LE Set Advertising Parameters  0x2006   Success
  < LE Set Advertising Enable      0x200a   Success
  < LE Create Connection Cancel    0x200e   Success
  > LE Connection Complete   Unknown Connection Identifier (0x02), central

Nothing follows either one; the next command is an unrelated scan restart
70 ms later. Over the whole capture: 7 LE Set Advertising Parameters sent,
all Success; 10 LE Set Advertising Enable, all Success; no Command
Disallowed of any opcode, and no 2 s cadence anywhere. Two central
connections to other peers completed normally afterwards, with feature
exchange and a connection parameter update, so advertising was still live
across the cancelled attempts.

The extended advertising case above is a code argument, not a measurement:
this controller has no LE Extended Advertising, so that path is not
exercised by the capture.

Fixes: fbd96c151c ("Bluetooth: Fix clearing HCI_LE_ADV for LE connections")
Cc: [email protected]
Assisted-by: Claude:claude-opus-5 btmon
Signed-off-by: Valentin Kindschi <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-08-24 13:11:42 -04:00
Valentin Kindschi ed5fb41d3b Bluetooth: hci_conn: re-enable advertising only for peripheral role
hci_le_conn_failed() unconditionally calls hci_enable_advertising(),
although its own comment states advertising should be re-enabled only
when the failed attempt was made as a peripheral.

hci_le_conn_failed() is reached from hci_conn_failed() for every failed
LE connection, including outgoing central connections. For a central
attempt this enable is redundant: hci_le_create_conn_sync() already
restores advertising via hci_resume_advertising_sync() in its done:
block. Because hci_enable_advertising() only queues the work on
cmd_sync_work, it runs *after* that resume has already succeeded and
set HCI_LE_ADV.

The resulting HCI sequence, captured on a BCM43455 (no LE Extended
Advertising, so legacy advertising is used):

  LE Create Connection                     Status Success
  ... 13.8 s, peer never answers ...
  LE Set Advertising Parameters (0x2006)   Success   <- done: resume,
  LE Set Advertising Enable     (0x200a)   Success      HCI_LE_ADV set
  LE Create Connection Cancel   (0x200e)   Success
  LE Connection Complete                   Unknown Conn Id
  LE Set Advertising Parameters (0x2006)   Command Disallowed (0x0c)

The last command is the queued enable from hci_le_conn_failed() running
as a second hci_enable_advertising_sync() pass. It clears HCI_LE_ADV
(hci_sync.c, "Clear the HCI_LE_ADV bit temporarily"), then sends
LE Set Advertising Parameters while the controller is still advertising,
which the controller correctly rejects with Command Disallowed.

The disable-first call at the top of hci_enable_advertising_sync()
cannot prevent this: hci_disable_advertising_sync() returns early
without sending anything when HCI_LE_ADV is clear, so it is a no-op
exactly when the flag is wrong.

hci_enable_advertising_sync() then returns without sending LE Set
Advertising Enable, so HCI_LE_ADV is never set again. The legacy
software rotation loop re-arms hci_schedule_adv_instance_sync() every
HCI_DEFAULT_ADV_DURATION (2 s), and its "already advertising" shortcut
tests HCI_LE_ADV, which can no longer become true. The command is
therefore retried every 2 s indefinitely:

  Bluetooth: hci0: Opcode 0x2006 failed: -16

Observed on a gateway as 5326 occurrences over 3 hours, ending only when
bluetoothd was restarted. Connection attempts that succeed do not call
hci_le_conn_failed() and never trigger this.

Add the role test the comment already describes. Both other
hci_enable_advertising() call sites reached from a failed/closed LE
connection (hci_cs_disconnect() and hci_disconn_complete_evt()) already
guard on conn->role == HCI_ROLE_SLAVE; this one was missed.

Reproducing needs legacy advertising (ext_adv_capable() false, so the
software rotation loop is used), simultaneous peripheral advertising and
outgoing central connects, and a central connect that times out rather
than failing fast.

The Fixes tag points at the commit that introduced the advertising
restart into this path for the directed-advertising (peripheral) case;
the role test that the later commit 0b1db38ca2 ("Bluetooth: Fix check
for direct advertising") added to the sibling paths was never applied
here.

Fixes: 3c857757ef ("Bluetooth: Add directed advertising support through connect()")
Cc: [email protected]
Assisted-by: Claude:claude-opus-5 btmon
Signed-off-by: Valentin Kindschi <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-08-24 13:11:33 -04:00
HyeongJun An 4beb198bc5 Bluetooth: eir: Fix OOB read in eir_get_service_data()
eir_get_service_data() walks the advertising data for a Service Data
field with a matching UUID.  On a mismatch it advances:

    eir += dlen;
    eir_len -= dlen;

eir_get_data() reports dlen as the field's data length, but the field
spans dlen + 2 bytes once its length and type bytes count, and more
when non-Service-Data fields were skipped to reach it.  The pointer
lands correctly on the next field.  eir_len does not, and the shortfall
compounds across fields until eir_get_data() reads the length and type
bytes of a "field" past the end of the buffer.

For an ISO broadcast sink that buffer is hcon->le_per_adv_data[], filled
from the periodic advertising reports of a remote broadcaster.  A PA
payload packed with mismatching Service Data fields walks off the array
into the rest of struct hci_conn.  A drifted field that matches the BAA
UUID puts those bytes in iso_pi(sk)->base, where user space reads them
back with getsockopt(BT_ISO_BASE).

Recompute eir_len from the end of the buffer each iteration.

Fixes: 8f9ae5b3ae ("Bluetooth: eir: Add helpers for managing service data")
Cc: [email protected]
Assisted-by: Claude:claude-opus-5
Signed-off-by: HyeongJun An <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-08-24 13:10:27 -04:00
Pauli Virtanen 5b9b68abb5 Bluetooth: hci_sync: add conditional locking annotations
Add context analysis annotations to functions doing conditional locking,
to suppress analysis warnings.

Fixes: cdc36db204 ("Bluetooth: hci_sync: Fix advertising data UAFs")
Tested-by: Nathan Chancellor <[email protected]> # build
Signed-off-by: Pauli Virtanen <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
2026-08-24 13:08:00 -04:00