iio: proximity: as3935: fix buffer stack trashing

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: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/iio/proximity/as3935.c b/drivers/iio/proximity/as3935.c
index 07f187818905fd4ebb3bd01fa709c93c651d96b6..37c1bb2afd08add43d8686705f69c8dcf593b90c 100644 (file)
--- 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_handler(int irq, void *private)
        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);