Commit e4eea890 authored by Dan Carpenter's avatar Dan Carpenter Committed by Luiz Augusto von Dentz
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Bluetooth: vhci: Fix info leak in force_devcd_write() 



There are a number of bugs here:

1) If "count" is less than sizeof(dump_data.data) then it copies
   uninitialized data.
2) If simple_write_to_buffer() returns -EFAULT then we run into a
   problem "ret < count" comparison.  "count" is an unsigned long so the
   comparison is type promoted to unsigned long and the negative returns
   become high positive values.  That also results in copying
   uninitialized data.
3) If "*ppos" is non-zero then the first part of the dump_data
   buffer is uninitialized.  Using copy_from_user() instead of
   simple_write_to_buffer() is more appropriate here.

Fixes: d5d5df6da0aa ("Bluetooth: Add vhci devcoredump support")
Signed-off-by: default avatarDan Carpenter <error27@gmail.com>
Signed-off-by: default avatarLuiz Augusto von Dentz <luiz.von.dentz@intel.com>
parent 0811ff48

drivers/bluetooth/hci_vhci.c

+10 −6
Original line number Diff line number Diff line
@@ -323,17 +323,21 @@ static ssize_t force_devcd_write(struct file *file, const char __user *user_buf, 
	struct hci_dev *hdev = data->hdev;

	struct sk_buff *skb = NULL;

	struct devcoredump_test_data dump_data;

	size_t data_size;

	int ret;



	ret = simple_write_to_buffer(&dump_data, sizeof(dump_data), ppos,

				     user_buf, count);

	if (ret < count)

		return ret;

	if (count < offsetof(struct devcoredump_test_data, data) ||

	    count > sizeof(dump_data))

		return -EINVAL;



	if (copy_from_user(&dump_data, user_buf, count))

		return -EFAULT;



	skb = alloc_skb(sizeof(dump_data.data), GFP_ATOMIC);

	data_size = count - offsetof(struct devcoredump_test_data, data);

	skb = alloc_skb(data_size, GFP_ATOMIC);

	if (!skb)

		return -ENOMEM;

	skb_put_data(skb, &dump_data.data, sizeof(dump_data.data));

	skb_put_data(skb, &dump_data.data, data_size);



	hci_devcd_register(hdev, vhci_coredump, vhci_coredump_hdr, NULL);