4.19-stable review patch. If anyone has any objections, please let me know.
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From: Takashi Iwai tiwai@suse.de
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: stable@vger.kernel.org Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- sound/core/oss/pcm_oss.c | 6 +++--- sound/core/oss/pcm_plugin.c | 6 +++--- 2 files changed, 6 insertions(+), 6 deletions(-)
--- 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_loc 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_substrea { 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); --- 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 s 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_p if (plugin->private_free) plugin->private_free(plugin); kfree(plugin->buf_channels); - vfree(plugin->buf); + kvfree(plugin->buf); kfree(plugin); return 0; }