blob: 6afd9d7fdaddda5a14aa0ce40aa04a2ffe55ba40 [file] [log] [blame]
From d1236852c12f9a834de19a7522c1a8ccd82c1e18 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Tue, 18 Feb 2020 12:17:37 +0100
Subject: [PATCH] ASoC: pcm: Fix possible buffer overflow in dpcm state sysfs
output
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: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c
index e1526548cfe8..34f832e1e4c3 100644
--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -3405,16 +3405,16 @@ static ssize_t dpcm_show_state(struct snd_soc_pcm_runtime *fe,
unsigned long flags;
/* 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)),
@@ -3422,10 +3422,10 @@ static ssize_t dpcm_show_state(struct snd_soc_pcm_runtime *fe,
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;
}
@@ -3435,16 +3435,16 @@ static ssize_t dpcm_show_state(struct snd_soc_pcm_runtime *fe,
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)),
--
2.7.4