From: Takashi Iwai <tiwai@xxxxxxx> commit 44eeb081b8630bb3ad3cd381d1ae1831463e48bb upstream. 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@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20200218091409.27162-1-tiwai@xxxxxxx Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- sound/hda/hdmi_chmap.c | 2 +- sound/pci/hda/hda_codec.c | 2 +- sound/pci/hda/hda_eld.c | 2 +- sound/pci/hda/hda_sysfs.c | 4 ++-- 4 files changed, 5 insertions(+), 5 deletions(-) --- a/sound/hda/hdmi_chmap.c +++ b/sound/hda/hdmi_chmap.c @@ -249,7 +249,7 @@ void snd_hdac_print_channel_allocation(i 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 */ --- a/sound/pci/hda/hda_codec.c +++ b/sound/pci/hda/hda_codec.c @@ -4019,7 +4019,7 @@ void snd_print_pcm_bits(int pcm, char *b 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 */ } --- a/sound/pci/hda/hda_eld.c +++ b/sound/pci/hda/hda_eld.c @@ -373,7 +373,7 @@ static void hdmi_print_pcm_rates(int pcm 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 */ --- a/sound/pci/hda/hda_sysfs.c +++ b/sound/pci/hda/hda_sysfs.c @@ -221,7 +221,7 @@ static ssize_t init_verbs_show(struct de 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); } @@ -271,7 +271,7 @@ static ssize_t hints_show(struct device 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);
