[PATCH 4.6 151/203] iio: proximity: as3935: fix buffer stack trashing

Greg Kroah-Hartman
2016-07-25T21:41:54Z

From: Matt Ranostay <mranostay@gmail.com>

commit 37b1ba2c68cfbe37f5f45bb91bcfaf2b016ae6a1 upstream.

Buffer wasn't of a valid size to allow the timestamp, and correct padding.
This patchset also moves the buffer off the stack, and onto the heap.

Cc: george.mccollister@gmail.com
Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/iio/proximity/as3935.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/iio/proximity/as3935.c
+++ b/drivers/iio/proximity/as3935.c
@@ -64,6 +64,7 @@ struct as3935_state {
struct delayed_work work;

u32 tune_cap;
+ u8 buffer[16]; /* 8-bit data + 56-bit padding + 64-bit timestamp */
u8 buf[2] ____cacheline_aligned;
};

@@ -212,9 +213,10 @@ static irqreturn_t as3935_trigger_handle
ret = as3935_read(st, AS3935_DATA, &val);
if (ret)
goto err_read;
- val &= AS3935_DATA_MASK;

- iio_push_to_buffers_with_timestamp(indio_dev, &val, pf->timestamp);
+ st->buffer[0] = val & AS3935_DATA_MASK;
+ iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
+ pf->timestamp);
err_read:
iio_trigger_notify_done(indio_dev->trig);