Commit bee60f01 authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: core: Copy string more safely 



Replace the remaining strcpy() and sprintf() usages in the ALSA core
code with the safer versions.

The first strcpy() points actually to card->id, hence just use
strscpy() with card->id instead.

The append of suffix string is slightly rewritten so that we can use
scnprintf() and strscpy().

Only for safety, no actual behavior change.

Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20250710100727.22653-104-tiwai@suse.de
parent 53beb4d0

sound/core/init.c

+7 −9
Original line number Diff line number Diff line
@@ -723,27 +723,25 @@ static void snd_card_set_id_no_lock(struct snd_card *card, const char *src, 
	 * ("card" conflicts with proc directories)

	 */

	if (!*id || !strncmp(id, "card", 4)) {

		strcpy(id, "Default");

		strscpy(card->id, "Default");

		is_default = true;

	}



	len = strlen(id);

	for (loops = 0; loops < SNDRV_CARDS; loops++) {

		char *spos;

		char sfxstr[5]; /* "_012" */

		int sfxlen;

		int sfxlen, slen;



		if (card_id_ok(card, id))

			return; /* OK */



		/* Add _XYZ suffix */

		sprintf(sfxstr, "_%X", loops + 1);

		sfxlen = strlen(sfxstr);

		sfxlen = scnprintf(sfxstr, sizeof(sfxstr), "_%X", loops + 1);

		if (len + sfxlen >= sizeof(card->id))

			spos = id + sizeof(card->id) - sfxlen - 1;

			slen = sizeof(card->id) - sfxlen - 1;

		else

			spos = id + len;

		strcpy(spos, sfxstr);

			slen = len;

		strscpy(id + slen, sfxstr, sizeof(card->id) - slen);

	}

	/* fallback to the default id */

	if (!is_default) {
@@ -801,7 +799,7 @@ static ssize_t id_store(struct device *dev, struct device_attribute *attr, 
	guard(mutex)(&snd_card_mutex);

	if (!card_id_ok(NULL, buf1))

		return -EEXIST;

	strcpy(card->id, buf1);

	strscpy(card->id, buf1);

	snd_info_card_id_change(card);



	return count;