[PATCH] ALSA: wavefront: Proper check of get_user() error

[Takashi Iwai]

The antient ISA wavefront driver reads its sample patch data (uploaded
over an ioctl) via __get_user() with no good reason; likely just for
some performance optimizations in the past.  Let's change this to the
standard get_user() and the error check for handling the fault case
properly.

Reported-by: Linus Torvalds <torvalds at linux-foundation.org>
Cc: <stable at vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/isa/wavefront/wavefront_synth.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sound/isa/wavefront/wavefront_synth.c b/sound/isa/wavefront/wavefront_synth.c
index 69cbc79fbb71..2aaaa6807174 100644
--- a/sound/isa/wavefront/wavefront_synth.c
+++ b/sound/isa/wavefront/wavefront_synth.c
@@ -1094,7 +1094,8 @@ wavefront_send_sample (snd_wavefront_t *dev,
 
 			if (dataptr < data_end) {
 		
-				__get_user (sample_short, dataptr);
+				if (get_user(sample_short, dataptr))
+					return -EFAULT;
 				dataptr += skip;
 		
 				if (data_is_unsigned) { /* GUS ? */
-- 
2.31.1