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| author | Takashi Iwai <tiwai@suse.de> | 2016-04-14 17:32:19 +0200 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2016-04-20 16:28:28 +0200 |
| commit | c7c999cb18da88a881e10e07f0724ad0bfaff770 (patch) | |
| tree | f211ce1476402b62d2395b04684ec86391fd0722 /drivers | |
| parent | 60f5f5d3a106dc5385b39348d13b20b15ac9cbf9 (diff) | |
| download | linux-c7c999cb18da88a881e10e07f0724ad0bfaff770.tar.gz linux-c7c999cb18da88a881e10e07f0724ad0bfaff770.tar.xz | |
Bluetooth: vhci: Fix race at creating hci device
hci_vhci driver creates a hci device object dynamically upon each
HCI_VENDOR_PKT write. Although it checks the already created object
and returns an error, it's still racy and may build multiple hci_dev
objects concurrently when parallel writes are performed, as the device
tracks only a single hci_dev object.
This patch introduces a mutex to protect against the concurrent device
creations.
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/bluetooth/hci_vhci.c | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/drivers/bluetooth/hci_vhci.c b/drivers/bluetooth/hci_vhci.c index f67ea1c090cb..aba31210c802 100644 --- a/drivers/bluetooth/hci_vhci.c +++ b/drivers/bluetooth/hci_vhci.c @@ -50,6 +50,7 @@ struct vhci_data { wait_queue_head_t read_wait; struct sk_buff_head readq; + struct mutex open_mutex; struct delayed_work open_timeout; }; @@ -87,12 +88,15 @@ static int vhci_send_frame(struct hci_dev *hdev, struct sk_buff *skb) return 0; } -static int vhci_create_device(struct vhci_data *data, __u8 opcode) +static int __vhci_create_device(struct vhci_data *data, __u8 opcode) { struct hci_dev *hdev; struct sk_buff *skb; __u8 dev_type; + if (data->hdev) + return -EBADFD; + /* bits 0-1 are dev_type (BR/EDR or AMP) */ dev_type = opcode & 0x03; @@ -151,6 +155,17 @@ static int vhci_create_device(struct vhci_data *data, __u8 opcode) return 0; } +static int vhci_create_device(struct vhci_data *data, __u8 opcode) +{ + int err; + + mutex_lock(&data->open_mutex); + err = __vhci_create_device(data, opcode); + mutex_unlock(&data->open_mutex); + + return err; +} + static inline ssize_t vhci_get_user(struct vhci_data *data, struct iov_iter *from) { @@ -191,11 +206,6 @@ static inline ssize_t vhci_get_user(struct vhci_data *data, case HCI_VENDOR_PKT: cancel_delayed_work_sync(&data->open_timeout); - if (data->hdev) { - kfree_skb(skb); - return -EBADFD; - } - opcode = *((__u8 *) skb->data); skb_pull(skb, 1); @@ -320,6 +330,7 @@ static int vhci_open(struct inode *inode, struct file *file) skb_queue_head_init(&data->readq); init_waitqueue_head(&data->read_wait); + mutex_init(&data->open_mutex); INIT_DELAYED_WORK(&data->open_timeout, vhci_open_timeout); file->private_data = data; |