[PATCH 4.16 200/272] ALSA: vmaster: Propagate slave error

Greg Kroah-Hartman
2018-05-28T11:36:40Z

From: Takashi Iwai <tiwai@suse.de>

[ Upstream commit 2e2c177ca84aff092c3c96714b0f6a12900f3946 ]

In slave_update() of vmaster code ignores the error from the slave
get() callback and copies the values. It's not only about the missing
error code but also that this may potentially lead to a leak of
uninitialized variables when the slave get() don't clear them.

This patch fixes slave_update() not to copy the potentially
uninitialized values when an error is returned from the slave get()
callback, and to propagate the error value properly.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
sound/core/vmaster.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/sound/core/vmaster.c
+++ b/sound/core/vmaster.c
@@ -68,10 +68,13 @@ static int slave_update(struct link_slav
return -ENOMEM;
uctl->id = slave->slave.id;
err = slave->slave.get(&slave->slave, uctl);
+ if (err < 0)
+ goto error;
for (ch = 0; ch < slave->info.count; ch++)
slave->vals[ch] = uctl->value.integer.value[ch];
+ error:
kfree(uctl);
- return 0;
+ return err < 0 ? err : 0;
}

/* get the slave ctl info and save the initial values */