diff options
| author | Tetsuo Handa | 2022-09-12 01:21:42 +0900 |
|---|---|---|
| committer | Luiz Augusto von Dentz | 2022-09-14 13:07:50 -0700 |
| commit | f74ca25d6d6629ffd4fd80a1a73037253b57d06b (patch) | |
| tree | db9f62d7bff8e263e85bc01d09a821a436ec9e38 /net/bluetooth | |
| parent | dd0a1794f4334ddbf9b7c5e7d642aaffff38c69b (diff) | |
Bluetooth: avoid hci_dev_test_and_set_flag() in mgmt_init_hdev()
syzbot is again reporting attempt to cancel uninitialized work
at mgmt_index_removed() [1], for setting of HCI_MGMT flag from
mgmt_init_hdev() from hci_mgmt_cmd() from hci_sock_sendmsg() can
race with testing of HCI_MGMT flag from mgmt_index_removed() from
hci_sock_bind() due to lack of serialization via hci_dev_lock().
Since mgmt_init_hdev() is called with mgmt_chan_list_lock held, we can
safely split hci_dev_test_and_set_flag() into hci_dev_test_flag() and
hci_dev_set_flag(). Thus, in order to close this race, set HCI_MGMT flag
after INIT_DELAYED_WORK() completed.
This is a local fix based on mgmt_chan_list_lock. Lack of serialization
via hci_dev_lock() might be causing different race conditions somewhere
else. But a global fix based on hci_dev_lock() should deserve a future
patch.
Link: https://syzkaller.appspot.com/bug?extid=844c7bf1b1aa4119c5de
Reported-by: syzbot+844c7bf1b1aa4119c5de@syzkaller.appspotmail.com
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: 3f2893d3c142986a ("Bluetooth: don't try to cancel uninitialized works at mgmt_index_removed()")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Diffstat (limited to 'net/bluetooth')
| -rw-r--r-- | net/bluetooth/mgmt.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index 4c421ebac669..b9b64030a7b0 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -1111,7 +1111,7 @@ static void mesh_send_done(struct work_struct *work) static void mgmt_init_hdev(struct sock *sk, struct hci_dev *hdev) { - if (hci_dev_test_and_set_flag(hdev, HCI_MGMT)) + if (hci_dev_test_flag(hdev, HCI_MGMT)) return; BT_INFO("MGMT ver %d.%d", MGMT_VERSION, MGMT_REVISION); @@ -1127,6 +1127,8 @@ static void mgmt_init_hdev(struct sock *sk, struct hci_dev *hdev) * it */ hci_dev_clear_flag(hdev, HCI_BONDABLE); + + hci_dev_set_flag(hdev, HCI_MGMT); } static int read_controller_info(struct sock *sk, struct hci_dev *hdev, |