ASoC: Intel: sof_sdw: Add space for a terminator into DAIs array

The code uses the initialised member of the asoc_sdw_dailink struct to
determine if a member of the array is in use. However in the case the
array is completely full this will lead to an access 1 past the end of
the array, expand the array by one entry to include a space for a
terminator.

Fixes: 27fd36a ("ASoC: Intel: sof-sdw: Add new code for parsing the snd_soc_acpi structs")
Reviewed-by: Bard Liao <[email protected]>
Reviewed-by: Péter Ujfalusi <[email protected]>
Signed-off-by: Charles Keepax <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mark Brown <[email protected]>

Author: charleskeepax

sound/soc/intel/boards/sof_sdw.c

@@ -1067,8 +1067,12 @@ static int sof_card_dai_links_create(struct snd_soc_card *card)
 		return ret;
 	}
 
-	/* One per DAI link, worst case is a DAI link for every endpoint */
-	sof_dais = kcalloc(num_ends, sizeof(*sof_dais), GFP_KERNEL);
+	/*
+	 * One per DAI link, worst case is a DAI link for every endpoint, also
+	 * add one additional to act as a terminator such that code can iterate
+	 * until it hits an uninitialised DAI.
+	 */
+	sof_dais = kcalloc(num_ends + 1, sizeof(*sof_dais), GFP_KERNEL);
 	if (!sof_dais)
 		return -ENOMEM;