From: Takashi Iwai tiwai@suse.de
commit 6c89ffea60aa3b2a33ae7987de1e84bfb89e4c9e upstream.
dpcm_show_state() invokes multiple snprintf() calls to concatenate formatted strings on the fixed size buffer. The usage of snprintf() is supposed for avoiding the buffer overflow, but it doesn't work as expected because snprintf() doesn't return the actual output size but the size to be written.
Fix this bug by replacing all snprintf() calls with scnprintf() calls.
Fixes: f86dcef87b77 ("ASoC: dpcm: Add debugFS support for DPCM") Signed-off-by: Takashi Iwai tiwai@suse.de Acked-by: Cezary Rojewski cezary.rojewski@intel.com Link: https://lore.kernel.org/r/20200218111737.14193-4-tiwai@suse.de Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- sound/soc/soc-pcm.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)
--- a/sound/soc/soc-pcm.c +++ b/sound/soc/soc-pcm.c @@ -3357,16 +3357,16 @@ static ssize_t dpcm_show_state(struct sn ssize_t offset = 0;
/* FE state */ - offset += snprintf(buf + offset, size - offset, + offset += scnprintf(buf + offset, size - offset, "[%s - %s]\n", fe->dai_link->name, stream ? "Capture" : "Playback");
- offset += snprintf(buf + offset, size - offset, "State: %s\n", + offset += scnprintf(buf + offset, size - offset, "State: %s\n", dpcm_state_string(fe->dpcm[stream].state));
if ((fe->dpcm[stream].state >= SND_SOC_DPCM_STATE_HW_PARAMS) && (fe->dpcm[stream].state <= SND_SOC_DPCM_STATE_STOP)) - offset += snprintf(buf + offset, size - offset, + offset += scnprintf(buf + offset, size - offset, "Hardware Params: " "Format = %s, Channels = %d, Rate = %d\n", snd_pcm_format_name(params_format(params)), @@ -3374,10 +3374,10 @@ static ssize_t dpcm_show_state(struct sn params_rate(params));
/* BEs state */ - offset += snprintf(buf + offset, size - offset, "Backends:\n"); + offset += scnprintf(buf + offset, size - offset, "Backends:\n");
if (list_empty(&fe->dpcm[stream].be_clients)) { - offset += snprintf(buf + offset, size - offset, + offset += scnprintf(buf + offset, size - offset, " No active DSP links\n"); goto out; } @@ -3386,16 +3386,16 @@ static ssize_t dpcm_show_state(struct sn struct snd_soc_pcm_runtime *be = dpcm->be; params = &dpcm->hw_params;
- offset += snprintf(buf + offset, size - offset, + offset += scnprintf(buf + offset, size - offset, "- %s\n", be->dai_link->name);
- offset += snprintf(buf + offset, size - offset, + offset += scnprintf(buf + offset, size - offset, " State: %s\n", dpcm_state_string(be->dpcm[stream].state));
if ((be->dpcm[stream].state >= SND_SOC_DPCM_STATE_HW_PARAMS) && (be->dpcm[stream].state <= SND_SOC_DPCM_STATE_STOP)) - offset += snprintf(buf + offset, size - offset, + offset += scnprintf(buf + offset, size - offset, " Hardware Params: " "Format = %s, Channels = %d, Rate = %d\n", snd_pcm_format_name(params_format(params)),