From: Luiz Augusto von Dentz luiz.von.dentz@intel.com
[ Upstream commit 975abc0c90fc485ff9b4a6afa475c3b1398d5d47 ]
This attempts to fix the following trace:
====================================================== WARNING: possible circular locking dependency detected 6.3.0-rc2-g68fcb3a7bf97 #4706 Not tainted ------------------------------------------------------ sco-tester/31 is trying to acquire lock: ffff8880025b8070 (&hdev->lock){+.+.}-{3:3}, at: sco_sock_getsockopt+0x1fc/0xa90
but task is already holding lock: ffff888001eeb130 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_sock_getsockopt+0x104/0xa90
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}: lock_sock_nested+0x32/0x80 sco_connect_cfm+0x118/0x4a0 hci_sync_conn_complete_evt+0x1e6/0x3d0 hci_event_packet+0x55c/0x7c0 hci_rx_work+0x34c/0xa00 process_one_work+0x575/0x910 worker_thread+0x89/0x6f0 kthread+0x14e/0x180 ret_from_fork+0x2b/0x50
-> #1 (hci_cb_list_lock){+.+.}-{3:3}: __mutex_lock+0x13b/0xcc0 hci_sync_conn_complete_evt+0x1ad/0x3d0 hci_event_packet+0x55c/0x7c0 hci_rx_work+0x34c/0xa00 process_one_work+0x575/0x910 worker_thread+0x89/0x6f0 kthread+0x14e/0x180 ret_from_fork+0x2b/0x50
-> #0 (&hdev->lock){+.+.}-{3:3}: __lock_acquire+0x18cc/0x3740 lock_acquire+0x151/0x3a0 __mutex_lock+0x13b/0xcc0 sco_sock_getsockopt+0x1fc/0xa90 __sys_getsockopt+0xe9/0x190 __x64_sys_getsockopt+0x5b/0x70 do_syscall_64+0x42/0x90 entry_SYSCALL_64_after_hwframe+0x70/0xda
other info that might help us debug this:
Chain exists of: &hdev->lock --> hci_cb_list_lock --> sk_lock-AF_BLUETOOTH-BTPROTO_SCO
Possible unsafe locking scenario:
CPU0 CPU1 ---- ---- lock(sk_lock-AF_BLUETOOTH-BTPROTO_SCO); lock(hci_cb_list_lock); lock(sk_lock-AF_BLUETOOTH-BTPROTO_SCO); lock(&hdev->lock);
*** DEADLOCK ***
1 lock held by sco-tester/31: #0: ffff888001eeb130 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_sock_getsockopt+0x104/0xa90
Fixes: 248733e87d50 ("Bluetooth: Allow querying of supported offload codecs over SCO socket") Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/bluetooth/sco.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c index 1111da4e2f2bd..1755f91a66f6a 100644 --- a/net/bluetooth/sco.c +++ b/net/bluetooth/sco.c @@ -1129,6 +1129,8 @@ static int sco_sock_getsockopt(struct socket *sock, int level, int optname, break; }
+ release_sock(sk); + /* find total buffer size required to copy codec + caps */ hci_dev_lock(hdev); list_for_each_entry(c, &hdev->local_codecs, list) { @@ -1146,15 +1148,13 @@ static int sco_sock_getsockopt(struct socket *sock, int level, int optname, buf_len += sizeof(struct bt_codecs); if (buf_len > len) { hci_dev_put(hdev); - err = -ENOBUFS; - break; + return -ENOBUFS; } ptr = optval;
if (put_user(num_codecs, ptr)) { hci_dev_put(hdev); - err = -EFAULT; - break; + return -EFAULT; } ptr += sizeof(num_codecs);
@@ -1194,12 +1194,14 @@ static int sco_sock_getsockopt(struct socket *sock, int level, int optname, ptr += len; }
- if (!err && put_user(buf_len, optlen)) - err = -EFAULT; - hci_dev_unlock(hdev); hci_dev_put(hdev);
+ lock_sock(sk); + + if (!err && put_user(buf_len, optlen)) + err = -EFAULT; + break;
default: