[PATCH 5.4 26/68] ALSA: wavefront: Proper check of get_user() error

Greg Kroah-Hartman
2022-05-23T17:24:18Z

From: Takashi Iwai <tiwai@suse.de>

commit a34ae6c0660d3b96b0055f68ef74dc9478852245 upstream.

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@linux-foundation.org>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220510103626.16635-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
sound/isa/wavefront/wavefront_synth.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/sound/isa/wavefront/wavefront_synth.c
+++ b/sound/isa/wavefront/wavefront_synth.c
@@ -1088,7 +1088,8 @@ wavefront_send_sample (snd_wavefront_t *

if (dataptr < data_end) {

- __get_user (sample_short, dataptr);
+ if (get_user(sample_short, dataptr))
+ return -EFAULT;
dataptr += skip;

if (data_is_unsigned) { /* GUS ? */