ASoC: topology: Fix wrong size check
authorAmadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
Thu, 10 Dec 2020 15:25:40 +0000 (10:25 -0500)
committerMark Brown <broonie@kernel.org>
Fri, 11 Dec 2020 13:23:01 +0000 (13:23 +0000)
commit631c78ed72bbf852cc09b24e4e4e412ed88770f2
tree3d1d12e3e166bdca6c2a1d3d13e325558f710e9d
parentf5824e5ce1cdba523a357a4d3ffbe0876a27330f
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>
sound/soc/soc-topology.c