From 27d6abfb99c871b7c0179b52b6a23acc6c7c005b Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Fri, 9 Nov 2018 11:59:45 +0100 Subject: [PATCH] ALSA: oss: Use kvzalloc() for local buffer allocations commit 65766ee0bf7fe8b3be80e2e1c3ef54ad59b29476 upstream. PCM OSS layer may allocate a few temporary buffers, one for the core read/write and another for the conversions via plugins. Currently both are allocated via vmalloc(). But as the allocation size is equivalent with the PCM period size, the required size might be quite small, depending on the application. This patch replaces these vmalloc() calls with kvzalloc() for covering small period sizes better. Also, we use "z"-alloc variant here for addressing the possible uninitialized access reported by syzkaller. Reported-by: syzbot+1cb36954e127c98dd037@syzkaller.appspotmail.com Cc: Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/core/oss/pcm_oss.c | 6 +++--- sound/core/oss/pcm_plugin.c | 6 +++--- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c index f8d4a419f3af..467039b342b5 100644 --- a/sound/core/oss/pcm_oss.c +++ b/sound/core/oss/pcm_oss.c @@ -1062,8 +1062,8 @@ static int snd_pcm_oss_change_params_locked(struct snd_pcm_substream *substream) runtime->oss.channels = params_channels(params); runtime->oss.rate = params_rate(params); - vfree(runtime->oss.buffer); - runtime->oss.buffer = vmalloc(runtime->oss.period_bytes); + kvfree(runtime->oss.buffer); + runtime->oss.buffer = kvzalloc(runtime->oss.period_bytes, GFP_KERNEL); if (!runtime->oss.buffer) { err = -ENOMEM; goto failure; @@ -2328,7 +2328,7 @@ static void snd_pcm_oss_release_substream(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime; runtime = substream->runtime; - vfree(runtime->oss.buffer); + kvfree(runtime->oss.buffer); runtime->oss.buffer = NULL; #ifdef CONFIG_SND_PCM_OSS_PLUGINS snd_pcm_oss_plugin_clear(substream); diff --git a/sound/core/oss/pcm_plugin.c b/sound/core/oss/pcm_plugin.c index 0391cb1a4f19..71571d992159 100644 --- a/sound/core/oss/pcm_plugin.c +++ b/sound/core/oss/pcm_plugin.c @@ -66,8 +66,8 @@ static int snd_pcm_plugin_alloc(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t return -ENXIO; size /= 8; if (plugin->buf_frames < frames) { - vfree(plugin->buf); - plugin->buf = vmalloc(size); + kvfree(plugin->buf); + plugin->buf = kvzalloc(size, GFP_KERNEL); plugin->buf_frames = frames; } if (!plugin->buf) { @@ -191,7 +191,7 @@ int snd_pcm_plugin_free(struct snd_pcm_plugin *plugin) if (plugin->private_free) plugin->private_free(plugin); kfree(plugin->buf_channels); - vfree(plugin->buf); + kvfree(plugin->buf); kfree(plugin); return 0; }