diff mbox series

Bluetooth: ISO: Fix possible circular locking dependency

Message ID 20230110213034.3629396-1-luiz.dentz@gmail.com
State New
Headers show
Series Bluetooth: ISO: Fix possible circular locking dependency | expand

Commit Message

Luiz Augusto von Dentz Jan. 10, 2023, 9:30 p.m. UTC 
From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

This attempts to fix the following trace:

kworker/u3:1/184 is trying to acquire lock:
ffff888001888130 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}, at:
iso_connect_cfm+0x2de/0x690

but task is already holding lock:
ffff8880028d1c20 (&conn->lock){+.+.}-{2:2}, at:
iso_connect_cfm+0x265/0x690

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&conn->lock){+.+.}-{2:2}:
       lock_acquire+0x176/0x3d0
       _raw_spin_lock+0x2a/0x40
       __iso_sock_close+0x1dd/0x4f0
       iso_sock_release+0xa0/0x1b0
       sock_close+0x5e/0x120
       __fput+0x102/0x410
       task_work_run+0xf1/0x160
       exit_to_user_mode_prepare+0x170/0x180
       syscall_exit_to_user_mode+0x19/0x50
       do_syscall_64+0x4e/0x90
       entry_SYSCALL_64_after_hwframe+0x62/0xcc

-> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}:
       check_prev_add+0xfc/0x1190
       __lock_acquire+0x1e27/0x2750
       lock_acquire+0x176/0x3d0
       lock_sock_nested+0x32/0x80
       iso_connect_cfm+0x2de/0x690
       hci_cc_le_setup_iso_path+0x195/0x340
       hci_cmd_complete_evt+0x1ae/0x500
       hci_event_packet+0x38e/0x7c0
       hci_rx_work+0x34c/0x980
       process_one_work+0x5a5/0x9a0
       worker_thread+0x89/0x6f0
       kthread+0x14e/0x180
       ret_from_fork+0x22/0x30

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&conn->lock);
                               lock(sk_lock-AF_BLUETOOTH-BTPROTO_ISO);
                               lock(&conn->lock);
  lock(sk_lock-AF_BLUETOOTH-BTPROTO_ISO);

 *** DEADLOCK ***

Fixes: ccf74f2390d6 ("Bluetooth: Add BTPROTO_ISO socket type")
Fixes: f764a6c2c1e4 ("Bluetooth: ISO: Add broadcast support")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
 net/bluetooth/iso.c | 61 +++++++++++++++++++--------------------------
 1 file changed, 26 insertions(+), 35 deletions(-)

Comments

bluez.test.bot@gmail.com Jan. 10, 2023, 9:57 p.m. UTC | #1 
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=710698

---Test result---

Test Summary:
CheckPatch                    PASS      0.90 seconds
GitLint                       PASS      0.32 seconds
SubjectPrefix                 PASS      0.09 seconds
BuildKernel                   PASS      31.83 seconds
CheckAllWarning               PASS      35.21 seconds
CheckSparse                   PASS      39.26 seconds
CheckSmatch                   PASS      107.05 seconds
BuildKernel32                 PASS      30.59 seconds
TestRunnerSetup               PASS      441.39 seconds
TestRunner_l2cap-tester       PASS      16.59 seconds
TestRunner_iso-tester         PASS      17.17 seconds
TestRunner_bnep-tester        PASS      5.83 seconds
TestRunner_mgmt-tester        PASS      111.56 seconds
TestRunner_rfcomm-tester      PASS      9.17 seconds
TestRunner_sco-tester         PASS      8.40 seconds
TestRunner_ioctl-tester       PASS      9.85 seconds
TestRunner_mesh-tester        PASS      7.22 seconds
TestRunner_smp-tester         PASS      8.31 seconds
TestRunner_userchan-tester    PASS      6.11 seconds
IncrementalBuild              PASS      29.04 seconds



---
Regards,
Linux Bluetooth
diff mbox series

Patch

diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c
index 035bb5d25f85..6157bc12b373 100644
--- a/net/bluetooth/iso.c
+++ b/net/bluetooth/iso.c
@@ -289,15 +289,15 @@  static int iso_connect_bis(struct sock *sk)
 	hci_dev_unlock(hdev);
 	hci_dev_put(hdev);
 
+	err = iso_chan_add(conn, sk, NULL);
+	if (err)
+		return err;
+
 	lock_sock(sk);
 
 	/* Update source addr of the socket */
 	bacpy(&iso_pi(sk)->src, &hcon->src);
 
-	err = iso_chan_add(conn, sk, NULL);
-	if (err)
-		goto release;
-
 	if (hcon->state == BT_CONNECTED) {
 		iso_sock_clear_timer(sk);
 		sk->sk_state = BT_CONNECTED;
@@ -306,7 +306,6 @@  static int iso_connect_bis(struct sock *sk)
 		iso_sock_set_timer(sk, sk->sk_sndtimeo);
 	}
 
-release:
 	release_sock(sk);
 	return err;
 
@@ -372,15 +371,15 @@  static int iso_connect_cis(struct sock *sk)
 	hci_dev_unlock(hdev);
 	hci_dev_put(hdev);
 
+	err = iso_chan_add(conn, sk, NULL);
+	if (err)
+		return err;
+
 	lock_sock(sk);
 
 	/* Update source addr of the socket */
 	bacpy(&iso_pi(sk)->src, &hcon->src);
 
-	err = iso_chan_add(conn, sk, NULL);
-	if (err)
-		goto release;
-
 	if (hcon->state == BT_CONNECTED) {
 		iso_sock_clear_timer(sk);
 		sk->sk_state = BT_CONNECTED;
@@ -392,7 +391,6 @@  static int iso_connect_cis(struct sock *sk)
 		iso_sock_set_timer(sk, sk->sk_sndtimeo);
 	}
 
-release:
 	release_sock(sk);
 	return err;
 
@@ -1432,33 +1430,29 @@  static void iso_conn_ready(struct iso_conn *conn)
 	struct sock *parent;
 	struct sock *sk = conn->sk;
 	struct hci_ev_le_big_sync_estabilished *ev;
+	struct hci_conn *hcon;
 
 	BT_DBG("conn %p", conn);
 
 	if (sk) {
 		iso_sock_ready(conn->sk);
 	} else {
-		iso_conn_lock(conn);
-
-		if (!conn->hcon) {
-			iso_conn_unlock(conn);
+		hcon = conn->hcon;
+		if (!hcon)
 			return;
-		}
 
-		ev = hci_recv_event_data(conn->hcon->hdev,
+		ev = hci_recv_event_data(hcon->hdev,
 					 HCI_EVT_LE_BIG_SYNC_ESTABILISHED);
 		if (ev)
-			parent = iso_get_sock_listen(&conn->hcon->src,
-						     &conn->hcon->dst,
+			parent = iso_get_sock_listen(&hcon->src,
+						     &hcon->dst,
 						     iso_match_big, ev);
 		else
-			parent = iso_get_sock_listen(&conn->hcon->src,
+			parent = iso_get_sock_listen(&hcon->src,
 						     BDADDR_ANY, NULL, NULL);
 
-		if (!parent) {
-			iso_conn_unlock(conn);
+		if (!parent)
 			return;
-		}
 
 		lock_sock(parent);
 
@@ -1466,30 +1460,29 @@  static void iso_conn_ready(struct iso_conn *conn)
 				    BTPROTO_ISO, GFP_ATOMIC, 0);
 		if (!sk) {
 			release_sock(parent);
-			iso_conn_unlock(conn);
 			return;
 		}
 
 		iso_sock_init(sk, parent);
 
-		bacpy(&iso_pi(sk)->src, &conn->hcon->src);
-		iso_pi(sk)->src_type = conn->hcon->src_type;
+		bacpy(&iso_pi(sk)->src, &hcon->src);
+		iso_pi(sk)->src_type = hcon->src_type;
 
 		/* If hcon has no destination address (BDADDR_ANY) it means it
 		 * was created by HCI_EV_LE_BIG_SYNC_ESTABILISHED so we need to
 		 * initialize using the parent socket destination address.
 		 */
-		if (!bacmp(&conn->hcon->dst, BDADDR_ANY)) {
-			bacpy(&conn->hcon->dst, &iso_pi(parent)->dst);
-			conn->hcon->dst_type = iso_pi(parent)->dst_type;
-			conn->hcon->sync_handle = iso_pi(parent)->sync_handle;
+		if (!bacmp(&hcon->dst, BDADDR_ANY)) {
+			bacpy(&hcon->dst, &iso_pi(parent)->dst);
+			hcon->dst_type = iso_pi(parent)->dst_type;
+			hcon->sync_handle = iso_pi(parent)->sync_handle;
 		}
 
-		bacpy(&iso_pi(sk)->dst, &conn->hcon->dst);
-		iso_pi(sk)->dst_type = conn->hcon->dst_type;
+		bacpy(&iso_pi(sk)->dst, &hcon->dst);
+		iso_pi(sk)->dst_type = hcon->dst_type;
 
-		hci_conn_hold(conn->hcon);
-		__iso_chan_add(conn, sk, parent);
+		hci_conn_hold(hcon);
+		iso_chan_add(conn, sk, parent);
 
 		if (test_bit(BT_SK_DEFER_SETUP, &bt_sk(parent)->flags))
 			sk->sk_state = BT_CONNECT2;
@@ -1500,8 +1493,6 @@  static void iso_conn_ready(struct iso_conn *conn)
 		parent->sk_data_ready(parent);
 
 		release_sock(parent);
-
-		iso_conn_unlock(conn);
 	}
 }