Am 04.12.2017 um 12:33 schrieb Dan Carpenter:
On Sun, Dec 03, 2017 at 04:17:26PM +0100, Simon Sandström wrote:
diff --git a/drivers/staging/pi433/pi433_if.h b/drivers/staging/pi433/pi433_if.h
index 34ff0d4807bd..bcfe29840889 100644
--- a/drivers/staging/pi433/pi433_if.h
+++ b/drivers/staging/pi433/pi433_if.h
@@ -63,7 +63,7 @@ struct pi433_tx_cfg {
__u16 bit_rate;
__u32 dev_frequency;
enum modulation modulation;
- enum modShaping modShaping;
+ enum mod_shaping mod_shaping;
I looked at how mod_shaping is set and the only place is in the ioctl:
789 case PI433_IOC_WR_TX_CFG:
790 if (copy_from_user(&instance->tx_cfg, argp,
791 sizeof(struct pi433_tx_cfg)))
792 return -EFAULT;
793 break;
We just write over the whole config. Including important things like
rx_cfg.fixed_message_length. There is no locking so when we do things
like:
385 /* fixed or unlimited length? */
386 if (dev->rx_cfg.fixed_message_length != 0)
387 {
388 if (dev->rx_cfg.fixed_message_length >
dev->rx_buffer_size)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
check
389 {
390 retval = -1;
391 goto abort;
392 }
393 bytes_total = dev->rx_cfg.fixed_message_length;
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
set this in the ioctl after the check but before this line and it looks
like a security problem.
394 dev_dbg(dev->dev,"rx: msg len set to %d by fixed
length", bytes_total);
395 }
Anyway, I guess this patch is fine.
regards,
dan carpenter
Hi Dan,
you are mixing rx and tx. The part from IOCTL is copied from the
tx-part, the lower part is dealing with rx.
With rx there should be no problem, since IOCTL is blocked, as long as
an rx operation is going on.
With tx, I also expect no problems, since instance->tx_cfg is never used
to configure the rf69. Everytime, you pass in new data via write() a
copy of tx_cfg is made. Transmission is done, using the copy of the
tx_cfg, never by using instance->tx_cfg.
But maybe I didn't got your point and misunderstand your intention.
Cheers,
Marcus
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