Unverified Commit 631c78ed authored Dec 10, 2020 by Amadeusz Sławiński Committed by Mark Brown Dec 11, 2020

ASoC: topology: Fix wrong size check

Dan reported that smatch reports wrong size check and after analysis it
is confirmed that we are comparing wrong value: pointer size instead of
array size. However the check itself is problematic as in UAPI header
there are two fields:

struct snd_soc_tplg_enum_control {
    (...)
    char texts[SND_SOC_TPLG_NUM_TEXTS][SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
    __le32 values[SND_SOC_TPLG_NUM_TEXTS * SNDRV_CTL_ELEM_ID_NAME_MAXLEN / 4];

the texts field is for names and the values one for values assigned to
those named fields, after analysis it becomes clear that there is quite
a lot overhead values than we may possibly name. So instead of changing
check to ARRAY_SIZE(ec->values), as it was first suggested, use
hardcoded value of SND_SOC_TPLG_NUM_TEXTS.

Link: https://lore.kernel.org/alsa-devel/X9B0eDcKy+9B6kZl@mwanda/


Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Link: https://lore.kernel.org/r/20201210152541.191728-1-amadeuszx.slawinski@linux.intel.com


Signed-off-by: Mark Brown <broonie@kernel.org>

parent f5824e5c

sound/soc/soc-topology.c

+8 −2

Original line number	Diff line number	Diff line
		@@ -892,10 +892,16 @@ static int soc_tplg_denum_create_values(struct soc_tplg tplg, struct soc_enum
		{
		int i;

		if (le32_to_cpu(ec->items) > sizeof(*ec->values))
		/*
		* Following "if" checks if we have at most SND_SOC_TPLG_NUM_TEXTS
		* values instead of using ARRAY_SIZE(ec->values) due to the fact that
		* it is oversized for its purpose. Additionally it is done so because
		* it is defined in UAPI header where it can't be easily changed.
		*/
		if (le32_to_cpu(ec->items) > SND_SOC_TPLG_NUM_TEXTS)
		return -EINVAL;

		se->dobj.control.dvalues = devm_kzalloc(tplg->dev, le32_to_cpu(ec->items) *
		se->dobj.control.dvalues = devm_kcalloc(tplg->dev, le32_to_cpu(ec->items),
		sizeof(u32),
		GFP_KERNEL);
		if (!se->dobj.control.dvalues)

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