[PATCH 4.19 09/37] ALSA: pcm: oss: Place the plugin buffer overflow checks correctly

Greg Kroah-Hartman
2020-05-04T18:01:51Z

From: Takashi Iwai <tiwai@suse.de>

commit 4285de0725b1bf73608abbcd35ad7fd3ddc0b61e upstream.

The checks of the plugin buffer overflow in the previous fix by commit
f2ecf903ef06 ("ALSA: pcm: oss: Avoid plugin buffer overflow")
are put in the wrong places mistakenly, which leads to the expected
(repeated) sound when the rate plugin is involved. Fix in the right
places.

Also, at those right places, the zero check is needed for the
termination node, so added there as well, and let's get it done,
finally.

Fixes: f2ecf903ef06 ("ALSA: pcm: oss: Avoid plugin buffer overflow")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200424193350.19678-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
sound/core/oss/pcm_plugin.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)

--- a/sound/core/oss/pcm_plugin.c
+++ b/sound/core/oss/pcm_plugin.c
@@ -211,21 +211,23 @@ static snd_pcm_sframes_t plug_client_siz
if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
plugin = snd_pcm_plug_last(plug);
while (plugin && drv_frames > 0) {
- if (check_size && drv_frames > plugin->buf_frames)
- drv_frames = plugin->buf_frames;
plugin_prev = plugin->prev;
if (plugin->src_frames)
drv_frames = plugin->src_frames(plugin, drv_frames);
+ if (check_size && plugin->buf_frames &&
+ drv_frames > plugin->buf_frames)
+ drv_frames = plugin->buf_frames;
plugin = plugin_prev;
}
} else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
plugin = snd_pcm_plug_first(plug);
while (plugin && drv_frames > 0) {
plugin_next = plugin->next;
+ if (check_size && plugin->buf_frames &&
+ drv_frames > plugin->buf_frames)
+ drv_frames = plugin->buf_frames;
if (plugin->dst_frames)
drv_frames = plugin->dst_frames(plugin, drv_frames);
- if (check_size && drv_frames > plugin->buf_frames)
- drv_frames = plugin->buf_frames;
plugin = plugin_next;
}
} else
@@ -251,26 +253,28 @@ static snd_pcm_sframes_t plug_slave_size
plugin = snd_pcm_plug_first(plug);
while (plugin && frames > 0) {
plugin_next = plugin->next;
+ if (check_size && plugin->buf_frames &&
+ frames > plugin->buf_frames)
+ frames = plugin->buf_frames;
if (plugin->dst_frames) {
frames = plugin->dst_frames(plugin, frames);
if (frames < 0)
return frames;
}
- if (check_size && frames > plugin->buf_frames)
- frames = plugin->buf_frames;
plugin = plugin_next;
}
} else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
plugin = snd_pcm_plug_last(plug);
while (plugin) {
- if (check_size && frames > plugin->buf_frames)
- frames = plugin->buf_frames;
plugin_prev = plugin->prev;
if (plugin->src_frames) {
frames = plugin->src_frames(plugin, frames);
if (frames < 0)
return frames;
}
+ if (check_size && plugin->buf_frames &&
+ frames > plugin->buf_frames)
+ frames = plugin->buf_frames;
plugin = plugin_prev;
}
} else