Unverified Commit ee8a41cd authored by Fred Oh's avatar Fred Oh Committed by Mark Brown
Browse files

ASoC: rt1011: fix KASAN out-of-bounds bug in find_next_bit() 



KASAN throws the following warning in rt1011.c:
[ 170.777603] BUG: KASAN: stack-out-of-bounds in _find_next_bit.constprop.0+0x3e/0xf0

find_next_bit() relies on unsigned long pointer arguments, but this driver
uses a type cast that generates the KASAN warning. Replace find_next_bit()
and find_last_bit() with __ffs() and __fls() to pass the value and avoid
casting pointers to make the warning go away.

Signed-off-by: default avatarFred Oh <fred.oh@linux.intel.com>
Signed-off-by: default avatarPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: default avatarGuennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Link: https://lore.kernel.org/r/20200622151348.28063-1-pierre-louis.bossart@linux.intel.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent b1647f9f

sound/soc/codecs/rt1011.c

+13 −7
Original line number Diff line number Diff line
@@ -1849,13 +1849,13 @@ static int rt1011_set_tdm_slot(struct snd_soc_dai *dai, 


	/* Rx slot configuration */

	rx_slotnum = hweight_long(rx_mask);

	first_bit = find_next_bit((unsigned long *)&rx_mask, 32, 0);

	if (rx_slotnum > 1 || rx_slotnum == 0) {

	if (rx_slotnum > 1 || !rx_slotnum) {

		ret = -EINVAL;

		dev_dbg(component->dev, "too many rx slots or zero slot\n");

		dev_err(component->dev, "too many rx slots or zero slot\n");

		goto _set_tdm_err_;

	}



	first_bit = __ffs(rx_mask);

	switch (first_bit) {

	case 0:

	case 2:
@@ -1892,11 +1892,17 @@ static int rt1011_set_tdm_slot(struct snd_soc_dai *dai, 


	/* Tx slot configuration */

	tx_slotnum = hweight_long(tx_mask);

	first_bit = find_next_bit((unsigned long *)&tx_mask, 32, 0);

	last_bit = find_last_bit((unsigned long *)&tx_mask, 32);

	if (tx_slotnum > 2 || (last_bit-first_bit) > 1) {

	if (tx_slotnum > 2 || !tx_slotnum) {

		ret = -EINVAL;

		dev_dbg(component->dev, "too many tx slots or tx slot location error\n");

		dev_err(component->dev, "too many tx slots or zero slot\n");

		goto _set_tdm_err_;

	}



	first_bit = __ffs(tx_mask);

	last_bit = __fls(tx_mask);

	if (last_bit - first_bit > 1) {

		ret = -EINVAL;

		dev_err(component->dev, "tx slot location error\n");

		goto _set_tdm_err_;

	}