From: Luiz Augusto von Dentz luiz.von.dentz@intel.com
[ Upstream commit 241f51931c35085449502c10f64fb3ecd6e02171 ]
This attempts to avoid circular locking dependency between sock_lock and hdev_lock:
WARNING: possible circular locking dependency detected 6.0.0-rc7-03728-g18dd8ab0a783 #3 Not tainted ------------------------------------------------------ kworker/u3:2/53 is trying to acquire lock: ffff888000254130 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}, at: iso_conn_del+0xbd/0x1d0 but task is already holding lock: ffffffff9f39a080 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_le_cis_estabilished_evt+0x1b5/0x500 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (hci_cb_list_lock){+.+.}-{3:3}: __mutex_lock+0x10e/0xfe0 hci_le_remote_feat_complete_evt+0x17f/0x320 hci_event_packet+0x39c/0x7d0 hci_rx_work+0x2bf/0x950 process_one_work+0x569/0x980 worker_thread+0x2a3/0x6f0 kthread+0x153/0x180 ret_from_fork+0x22/0x30 -> #1 (&hdev->lock){+.+.}-{3:3}: __mutex_lock+0x10e/0xfe0 iso_connect_cis+0x6f/0x5a0 iso_sock_connect+0x1af/0x710 __sys_connect+0x17e/0x1b0 __x64_sys_connect+0x37/0x50 do_syscall_64+0x43/0x90 entry_SYSCALL_64_after_hwframe+0x62/0xcc -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}: __lock_acquire+0x1b51/0x33d0 lock_acquire+0x16f/0x3b0 lock_sock_nested+0x32/0x80 iso_conn_del+0xbd/0x1d0 iso_connect_cfm+0x226/0x680 hci_le_cis_estabilished_evt+0x1ed/0x500 hci_event_packet+0x39c/0x7d0 hci_rx_work+0x2bf/0x950 process_one_work+0x569/0x980 worker_thread+0x2a3/0x6f0 kthread+0x153/0x180 ret_from_fork+0x22/0x30 other info that might help us debug this: Chain exists of: sk_lock-AF_BLUETOOTH-BTPROTO_ISO --> &hdev->lock --> hci_cb_list_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(hci_cb_list_lock); lock(&hdev->lock); lock(hci_cb_list_lock); lock(sk_lock-AF_BLUETOOTH-BTPROTO_ISO); *** DEADLOCK *** 4 locks held by kworker/u3:2/53: #0: ffff8880021d9130 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work+0x4ad/0x980 #1: ffff888002387de0 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x4ad/0x980 #2: ffff888001ac0070 (&hdev->lock){+.+.}-{3:3}, at: hci_le_cis_estabilished_evt+0xc3/0x500 #3: ffffffff9f39a080 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_le_cis_estabilished_evt+0x1b5/0x500
Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Stable-dep-of: 6a5ad251b7cd ("Bluetooth: ISO: Fix possible circular locking dependency") Signed-off-by: Sasha Levin sashal@kernel.org --- net/bluetooth/iso.c | 61 ++++++++++++++++++++++++++++----------------- 1 file changed, 38 insertions(+), 23 deletions(-)
diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c index 26db929b97c4..df57cbe27b3d 100644 --- a/net/bluetooth/iso.c +++ b/net/bluetooth/iso.c @@ -261,13 +261,13 @@ static int iso_connect_bis(struct sock *sk)
if (!bis_capable(hdev)) { err = -EOPNOTSUPP; - goto done; + goto unlock; }
/* Fail if out PHYs are marked as disabled */ if (!iso_pi(sk)->qos.out.phy) { err = -EINVAL; - goto done; + goto unlock; }
hcon = hci_connect_bis(hdev, &iso_pi(sk)->dst, iso_pi(sk)->dst_type, @@ -275,22 +275,27 @@ static int iso_connect_bis(struct sock *sk) iso_pi(sk)->base); if (IS_ERR(hcon)) { err = PTR_ERR(hcon); - goto done; + goto unlock; }
conn = iso_conn_add(hcon); if (!conn) { hci_conn_drop(hcon); err = -ENOMEM; - goto done; + goto unlock; }
+ hci_dev_unlock(hdev); + hci_dev_put(hdev); + + 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 done; + goto release;
if (hcon->state == BT_CONNECTED) { iso_sock_clear_timer(sk); @@ -300,7 +305,11 @@ static int iso_connect_bis(struct sock *sk) iso_sock_set_timer(sk, sk->sk_sndtimeo); }
-done: +release: + release_sock(sk); + return err; + +unlock: hci_dev_unlock(hdev); hci_dev_put(hdev); return err; @@ -324,13 +333,13 @@ static int iso_connect_cis(struct sock *sk)
if (!cis_central_capable(hdev)) { err = -EOPNOTSUPP; - goto done; + goto unlock; }
/* Fail if either PHYs are marked as disabled */ if (!iso_pi(sk)->qos.in.phy && !iso_pi(sk)->qos.out.phy) { err = -EINVAL; - goto done; + goto unlock; }
/* Just bind if DEFER_SETUP has been set */ @@ -340,7 +349,7 @@ static int iso_connect_cis(struct sock *sk) &iso_pi(sk)->qos); if (IS_ERR(hcon)) { err = PTR_ERR(hcon); - goto done; + goto unlock; } } else { hcon = hci_connect_cis(hdev, &iso_pi(sk)->dst, @@ -348,7 +357,7 @@ static int iso_connect_cis(struct sock *sk) &iso_pi(sk)->qos); if (IS_ERR(hcon)) { err = PTR_ERR(hcon); - goto done; + goto unlock; } }
@@ -356,15 +365,20 @@ static int iso_connect_cis(struct sock *sk) if (!conn) { hci_conn_drop(hcon); err = -ENOMEM; - goto done; + goto unlock; }
+ hci_dev_unlock(hdev); + hci_dev_put(hdev); + + 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 done; + goto release;
if (hcon->state == BT_CONNECTED) { iso_sock_clear_timer(sk); @@ -377,7 +391,11 @@ static int iso_connect_cis(struct sock *sk) iso_sock_set_timer(sk, sk->sk_sndtimeo); }
-done: +release: + release_sock(sk); + return err; + +unlock: hci_dev_unlock(hdev); hci_dev_put(hdev); return err; @@ -831,20 +849,23 @@ static int iso_sock_connect(struct socket *sock, struct sockaddr *addr, bacpy(&iso_pi(sk)->dst, &sa->iso_bdaddr); iso_pi(sk)->dst_type = sa->iso_bdaddr_type;
+ release_sock(sk); + if (bacmp(&iso_pi(sk)->dst, BDADDR_ANY)) err = iso_connect_cis(sk); else err = iso_connect_bis(sk);
if (err) - goto done; + return err; + + lock_sock(sk);
if (!test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags)) { err = bt_sock_wait_state(sk, BT_CONNECTED, sock_sndtimeo(sk, flags & O_NONBLOCK)); }
-done: release_sock(sk); return err; } @@ -1099,28 +1120,22 @@ static int iso_sock_recvmsg(struct socket *sock, struct msghdr *msg, { struct sock *sk = sock->sk; struct iso_pinfo *pi = iso_pi(sk); - int err;
BT_DBG("sk %p", sk);
- lock_sock(sk); - if (test_and_clear_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags)) { switch (sk->sk_state) { case BT_CONNECT2: + lock_sock(sk); iso_conn_defer_accept(pi->conn->hcon); sk->sk_state = BT_CONFIG; release_sock(sk); return 0; case BT_CONNECT: - err = iso_connect_cis(sk); - release_sock(sk); - return err; + return iso_connect_cis(sk); } }
- release_sock(sk); - return bt_sock_recvmsg(sock, msg, len, flags); }