ALSA: hda: Use scnprintf() for printing texts for sysfs/procfs

Some code in HD-audio driver calls snprintf() in a loop and still
expects that the return value were actually written size, while
snprintf() returns the expected would-be length instead.  When the
given buffer limit were small, this leads to a buffer overflow.

Use scnprintf() for addressing those issues.  It returns the actually
written size unlike snprintf().

Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200218091409.27162-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2020-02-18 10:14:09 +01:00
parent cc5049ae4d
commit 44eeb081b8
4 changed files with 5 additions and 5 deletions

View File

@ -250,7 +250,7 @@ void snd_hdac_print_channel_allocation(int spk_alloc, char *buf, int buflen)
for (i = 0, j = 0; i < ARRAY_SIZE(cea_speaker_allocation_names); i++) {
if (spk_alloc & (1 << i))
j += snprintf(buf + j, buflen - j, " %s",
j += scnprintf(buf + j, buflen - j, " %s",
cea_speaker_allocation_names[i]);
}
buf[j] = '\0'; /* necessary when j == 0 */

View File

@ -4022,7 +4022,7 @@ void snd_print_pcm_bits(int pcm, char *buf, int buflen)
for (i = 0, j = 0; i < ARRAY_SIZE(bits); i++)
if (pcm & (AC_SUPPCM_BITS_8 << i))
j += snprintf(buf + j, buflen - j, " %d", bits[i]);
j += scnprintf(buf + j, buflen - j, " %d", bits[i]);
buf[j] = '\0'; /* necessary when j == 0 */
}

View File

@ -360,7 +360,7 @@ static void hdmi_print_pcm_rates(int pcm, char *buf, int buflen)
for (i = 0, j = 0; i < ARRAY_SIZE(alsa_rates); i++)
if (pcm & (1 << i))
j += snprintf(buf + j, buflen - j, " %d",
j += scnprintf(buf + j, buflen - j, " %d",
alsa_rates[i]);
buf[j] = '\0'; /* necessary when j == 0 */

View File

@ -222,7 +222,7 @@ static ssize_t init_verbs_show(struct device *dev,
int i, len = 0;
mutex_lock(&codec->user_mutex);
snd_array_for_each(&codec->init_verbs, i, v) {
len += snprintf(buf + len, PAGE_SIZE - len,
len += scnprintf(buf + len, PAGE_SIZE - len,
"0x%02x 0x%03x 0x%04x\n",
v->nid, v->verb, v->param);
}
@ -272,7 +272,7 @@ static ssize_t hints_show(struct device *dev,
int i, len = 0;
mutex_lock(&codec->user_mutex);
snd_array_for_each(&codec->hints, i, hint) {
len += snprintf(buf + len, PAGE_SIZE - len,
len += scnprintf(buf + len, PAGE_SIZE - len,
"%s = %s\n", hint->key, hint->val);
}
mutex_unlock(&codec->user_mutex);