From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
cppcheck complains twice:
sound/soc/sof/control.c:436:2: style: Assignment of function parameter has no effect outside the function. [uselessAssignmentArg] size -= sizeof(const struct snd_ctl_tlv); ^
sound/soc/sof/control.c:436:7: style: Variable 'size' is assigned a value that is never used. [unreadVariable] size -= sizeof(const struct snd_ctl_tlv);
Somehow we dropped the checks for the size argument when upstreaming the code, somewhere between v5 and v6.
Re-add a size check to avoid providing userspace with more data that it asked for.
Also fix all error codes, we should return -ENOSPC instead of -EINVAL.
Fixes: c3078f5397046 ('ASoC: SOF: Add Sound Open Firmware KControl support') Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Reviewed-by: Ranjani Sridharan ranjani.sridharan@linux.intel.com Reviewed-by: Guennadi Liakhovetski guennadi.liakhovetski@linux.intel.com Signed-off-by: Kai Vehmanen kai.vehmanen@linux.intel.com --- sound/soc/sof/control.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/sound/soc/sof/control.c b/sound/soc/sof/control.c index 58f8c998e6af..8d499d0e331d 100644 --- a/sound/soc/sof/control.c +++ b/sound/soc/sof/control.c @@ -432,7 +432,9 @@ int snd_sof_bytes_ext_get(struct snd_kcontrol *kcontrol, * Decrement the limit by ext bytes header size to * ensure the user space buffer is not exceeded. */ - size -= sizeof(const struct snd_ctl_tlv); + if (size < sizeof(struct snd_ctl_tlv)) + return -ENOSPC; + size -= sizeof(struct snd_ctl_tlv);
/* set the ABI header values */ cdata->data->magic = SOF_ABI_MAGIC; @@ -448,6 +450,10 @@ int snd_sof_bytes_ext_get(struct snd_kcontrol *kcontrol,
data_size = cdata->data->size + sizeof(const struct sof_abi_hdr);
+ /* make sure we don't exceed size provided by user space for data */ + if (data_size > size) + return -ENOSPC; + header.numid = scontrol->cmd; header.length = data_size; if (copy_to_user(tlvd, &header, sizeof(const struct snd_ctl_tlv)))