Commit d278a9de authored by Jaroslav Kysela's avatar Jaroslav Kysela Committed by Takashi Iwai
Browse files

ALSA: core: add isascii() check to card ID generator 

The card identifier should contain only safe ASCII characters. The isalnum()
returns true also for characters for non-ASCII characters.

Link: https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/4135
Link: https://lore.kernel.org/linux-sound/yk3WTvKkwheOon_LzZlJ43PPInz6byYfBzpKkbasww1yzuiMRqn7n6Y8vZcXB-xwFCu_vb8hoNjv7DTNwH5TWjpEuiVsyn9HPCEXqwF4120=@protonmail.com/


Cc: stable@vger.kernel.org
Reported-by: default avatarBarnabás Pőcze <pobrn@protonmail.com>
Signed-off-by: default avatarJaroslav Kysela <perex@perex.cz>
Link: https://patch.msgid.link/20241002194649.1944696-1-perex@perex.cz


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 33027006

sound/core/init.c

+10 −4
Original line number Diff line number Diff line
@@ -654,13 +654,19 @@ void snd_card_free(struct snd_card *card) 
}

EXPORT_SYMBOL(snd_card_free);



/* check, if the character is in the valid ASCII range */

static inline bool safe_ascii_char(char c)

{

	return isascii(c) && isalnum(c);

}



/* retrieve the last word of shortname or longname */

static const char *retrieve_id_from_card_name(const char *name)

{

	const char *spos = name;



	while (*name) {

		if (isspace(*name) && isalnum(name[1]))

		if (isspace(*name) && safe_ascii_char(name[1]))

			spos = name + 1;

		name++;

	}
@@ -687,12 +693,12 @@ static void copy_valid_id_string(struct snd_card *card, const char *src, 
{

	char *id = card->id;



	while (*nid && !isalnum(*nid))

	while (*nid && !safe_ascii_char(*nid))

		nid++;

	if (isdigit(*nid))

		*id++ = isalpha(*src) ? *src : 'D';

	while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {

		if (isalnum(*nid))

		if (safe_ascii_char(*nid))

			*id++ = *nid;

		nid++;

	}
@@ -787,7 +793,7 @@ static ssize_t id_store(struct device *dev, struct device_attribute *attr, 


	for (idx = 0; idx < copy; idx++) {

		c = buf[idx];

		if (!isalnum(c) && c != '_' && c != '-')

		if (!safe_ascii_char(c) && c != '_' && c != '-')

			return -EINVAL;

	}

	memcpy(buf1, buf, copy);