* [PATCH] Bluetooth: hci_event: reject incoming conn request when MASTER conn exists
@ 2026-04-10 10:42 SeungJu Cheon
2026-04-10 11:08 ` bluez.test.bot
0 siblings, 1 reply; 2+ messages in thread
From: SeungJu Cheon @ 2026-04-10 10:42 UTC (permalink / raw)
To: linux-bluetooth
Cc: marcel, luiz.dentz, johan.hedberg, linux-kernel, me, shuah,
linux-kernel-mentees, SeungJu Cheon
hci_conn_request_evt() reuses an existing connection without checking
its role. When the existing connection has the MASTER role (outgoing
connection in progress), conn->state is incorrectly overwritten from
BT_CONNECTED or BT_OPEN to BT_CONNECT, causing state machine corruption.
This can lead to use-after-free or state confusion when the connection
is later disconnected.
The issue was observed during VHCI testing:
Thread 1: Local connect() -> conn created (role=MASTER, state=BT_OPEN)
Thread 2: Remote Connection Request received
-> hci_conn_hash_lookup_ba() finds existing MASTER conn
-> conn->state overwritten to BT_CONNECT (no role check!)
Fix by rejecting incoming connection requests when a MASTER connection
to the same address already exists.
Fixes: 70c464256310 ("Bluetooth: Refactor connection request handling")
Signed-off-by: SeungJu Cheon <suunj1331@gmail.com>
---
net/bluetooth/hci_event.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 286529d2e554..3d34cf2e5067 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -3327,6 +3327,12 @@ static void hci_conn_request_evt(struct hci_dev *hdev, void *data,
bt_dev_err(hdev, "connection err: %ld", PTR_ERR(conn));
goto unlock;
}
+ } else if (conn->role == HCI_ROLE_MASTER) {
+ /* Reject incoming request when outgoing connection to
+ * the same device is already in progress.
+ */
+ hci_reject_conn(hdev, &ev->bdaddr);
+ goto unlock;
}
memcpy(conn->dev_class, ev->dev_class, 3);
--
2.52.0
^ permalink raw reply related [flat|nested] 2+ messages in thread* RE: Bluetooth: hci_event: reject incoming conn request when MASTER conn exists
2026-04-10 10:42 [PATCH] Bluetooth: hci_event: reject incoming conn request when MASTER conn exists SeungJu Cheon
@ 2026-04-10 11:08 ` bluez.test.bot
0 siblings, 0 replies; 2+ messages in thread
From: bluez.test.bot @ 2026-04-10 11:08 UTC (permalink / raw)
To: linux-bluetooth, suunj1331
[-- Attachment #1: Type: text/plain, Size: 6870 bytes --]
This is automated email and please do not reply to this email!
Dear submitter,
Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=1079703
---Test result---
Test Summary:
CheckPatch PENDING 0.31 seconds
GitLint PENDING 0.26 seconds
SubjectPrefix PASS 0.12 seconds
BuildKernel PASS 25.00 seconds
CheckAllWarning PASS 27.20 seconds
CheckSparse PASS 25.98 seconds
BuildKernel32 PASS 23.93 seconds
TestRunnerSetup PASS 526.05 seconds
TestRunner_l2cap-tester PASS 27.68 seconds
TestRunner_iso-tester PASS 38.71 seconds
TestRunner_bnep-tester PASS 6.43 seconds
TestRunner_mgmt-tester FAIL 115.26 seconds
TestRunner_rfcomm-tester PASS 9.46 seconds
TestRunner_sco-tester FAIL 14.41 seconds
TestRunner_ioctl-tester PASS 10.15 seconds
TestRunner_mesh-tester FAIL 11.68 seconds
TestRunner_smp-tester PASS 8.61 seconds
TestRunner_userchan-tester PASS 6.93 seconds
TestRunner_6lowpan-tester FAIL 8.70 seconds
IncrementalBuild PENDING 0.29 seconds
Details
##############################
Test: CheckPatch - PENDING
Desc: Run checkpatch.pl script
Output:
##############################
Test: GitLint - PENDING
Desc: Run gitlint
Output:
##############################
Test: TestRunner_mgmt-tester - FAIL
Desc: Run mgmt-tester with test-runner
Output:
Total: 494, Passed: 489 (99.0%), Failed: 1, Not Run: 4
Failed Test Cases
Read Exp Feature - Success Failed 0.102 seconds
##############################
Test: TestRunner_sco-tester - FAIL
Desc: Run sco-tester with test-runner
Output:
WARNING: possible circular locking dependency detected
7.0.0-rc2-gc12cd1423cb0 #1 Not tainted
------------------------------------------------------
kworker/u5:2/117 is trying to acquire lock:
ffff888001946240 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_connect_cfm+0x358/0x8d0
but task is already holding lock:
ffff888002094c20 (&conn->lock){+.+.}-{3:3}, at: sco_connect_cfm+0x22d/0x8d0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&conn->lock){+.+.}-{3:3}:
lock_acquire+0xf7/0x2c0
_raw_spin_lock+0x2a/0x40
sco_sock_connect+0x4d7/0x1280
__sys_connect+0x1a3/0x260
__x64_sys_connect+0x6e/0xb0
do_syscall_64+0xa0/0x570
entry_SYSCALL_64_after_hwframe+0x74/0x7c
-> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}:
check_prev_add+0xe9/0xc70
__lock_acquire+0x1457/0x1df0
lock_acquire+0xf7/0x2c0
lock_sock_nested+0x36/0xd0
sco_connect_cfm+0x358/0x8d0
hci_sync_conn_complete_evt+0x3d3/0x8e0
hci_event_packet+0x74f/0xb10
hci_rx_work+0x398/0xd00
process_scheduled_works+0xb16/0x1ac0
worker_thread+0x4ff/0xba0
kthread+0x368/0x490
ret_from_fork+0x498/0x7e0
ret_from_fork_asm+0x19/0x30
other info that might help us debug this:
...
BUG: sleeping function called from invalid context at net/core/sock.c:3782
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 117, name: kworker/u5:2
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
INFO: lockdep is turned off.
CPU: 0 UID: 0 PID: 117 Comm: kworker/u5:2 Not tainted 7.0.0-rc2-gc12cd1423cb0 #1 PREEMPT(lazy)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Workqueue: hci0 hci_rx_work
Call Trace:
<TASK>
dump_stack_lvl+0x49/0x60
__might_resched+0x2ea/0x500
lock_sock_nested+0x47/0xd0
? sco_connect_cfm+0x358/0x8d0
sco_connect_cfm+0x358/0x8d0
? hci_debugfs_create_conn+0x190/0x210
? __pfx_sco_connect_cfm+0x10/0x10
hci_sync_conn_complete_evt+0x3d3/0x8e0
hci_event_packet+0x74f/0xb10
? __pfx_hci_sync_conn_complete_evt+0x10/0x10
? __pfx_hci_event_packet+0x10/0x10
? mark_held_locks+0x49/0x80
? lockdep_hardirqs_on_prepare+0xd4/0x180
? _raw_spin_unlock_irqrestore+0x2c/0x50
hci_rx_work+0x398/0xd00
process_scheduled_works+0xb16/0x1ac0
? __pfx_process_scheduled_works+0x10/0x10
? lock_acquire+0xf7/0x2c0
? lock_is_held_type+0x9b/0x110
? __pfx_hci_rx_work+0x10/0x10
worker_thread+0x4ff/0xba0
? _raw_spin_unlock_irqrestore+0x2c/0x50
? __pfx_worker_thread+0x10/0x10
kthread+0x368/0x490
? _raw_spin_unlock_irq+0x23/0x40
? __pfx_kthread+0x10/0x10
ret_from_fork+0x498/0x7e0
? __pfx_ret_from_fork+0x10/0x10
? __switch_to+0x9e4/0xe50
? __switch_to_asm+0x32/0x60
...
Total: 30, Passed: 30 (100.0%), Failed: 0, Not Run: 0
##############################
Test: TestRunner_mesh-tester - FAIL
Desc: Run mesh-tester with test-runner
Output:
Total: 10, Passed: 8 (80.0%), Failed: 2, Not Run: 0
Failed Test Cases
Mesh - Send cancel - 1 Timed out 1.872 seconds
Mesh - Send cancel - 2 Timed out 1.998 seconds
##############################
Test: TestRunner_6lowpan-tester - FAIL
Desc: Run 6lowpan-tester with test-runner
Output:
WARNING: possible circular locking dependency detected
7.0.0-rc2-gc12cd1423cb0 #1 Not tainted
------------------------------------------------------
kworker/0:1/11 is trying to acquire lock:
ffff888002482940 ((wq_completion)hci0#2){+.+.}-{0:0}, at: touch_wq_lockdep_map+0x75/0x180
but task is already holding lock:
ffffffff9004d720 (rtnl_mutex){+.+.}-{4:4}, at: lowpan_unregister_netdev+0xd/0x30
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (rtnl_mutex){+.+.}-{4:4}:
lock_acquire+0xf7/0x2c0
__mutex_lock+0x16b/0x1fc0
lowpan_register_netdev+0x11/0x30
chan_ready_cb+0x836/0xd00
l2cap_recv_frame+0x6a06/0x8920
l2cap_recv_acldata+0x790/0xdf0
hci_rx_work+0x500/0xd00
process_scheduled_works+0xb16/0x1ac0
worker_thread+0x4ff/0xba0
kthread+0x368/0x490
ret_from_fork+0x498/0x7e0
ret_from_fork_asm+0x19/0x30
-> #3 (&chan->lock#3/1){+.+.}-{4:4}:
lock_acquire+0xf7/0x2c0
__mutex_lock+0x16b/0x1fc0
l2cap_chan_connect+0x74e/0x1980
lowpan_control_write+0x523/0x660
full_proxy_write+0x10b/0x190
vfs_write+0x1c0/0xf60
ksys_write+0xf1/0x1d0
do_syscall_64+0xa0/0x570
entry_SYSCALL_64_after_hwframe+0x74/0x7c
-> #2 (&conn->lock){+.+.}-{4:4}:
...
Total: 8, Passed: 8 (100.0%), Failed: 0, Not Run: 0
##############################
Test: IncrementalBuild - PENDING
Desc: Incremental build with the patches in the series
Output:
https://github.com/bluez/bluetooth-next/pull/62
---
Regards,
Linux Bluetooth
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2026-04-10 11:08 ` bluez.test.bot
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