ALSA: pcm: Fix id copying in snd_pcm_set_sync_per_card()

Avoid to use strncpy and do proper length limiting (12 bytes)
to avoid out of array access.

Fixes: d712c58 ("ALSA: pcm: optimize and clarify stream synchronization ID API")
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Signed-off-by: Jaroslav Kysela <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Takashi Iwai <[email protected]>

Author: perexg

sound/core/pcm_lib.c

@@ -543,8 +543,8 @@ void snd_pcm_set_sync_per_card(struct snd_pcm_substream *substream,
 			       const unsigned char *id, unsigned int len)
 {
 	*(__u32 *)params->sync = cpu_to_le32(substream->pcm->card->number);
-	len = max(12, len);
-	strncpy(params->sync + 4, id, len);
+	len = min(12, len);
+	memcpy(params->sync + 4, id, len);
 	memset(params->sync + 4 + len, 0, 12 - len);
 }
 EXPORT_SYMBOL_GPL(snd_pcm_set_sync_per_card);