[PATCH 4.9 40/80] ALSA: usx2y: Fix potential NULL dereference

[Greg Kroah-Hartman]

From: Takashi Iwai <tiwai@xxxxxxx>

commit 7686e3485253635c529cdd5f416fc640abaf076f upstream.

The error handling code in usX2Y_rate_set() may hit a potential NULL
dereference when an error occurs before allocating all us->urb[].
Add a proper NULL check for fixing the corner case.

Reported-by: Lin Yi <teroincn@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200420075529.27203-1-tiwai@xxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 sound/usb/usx2y/usbusx2yaudio.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/sound/usb/usx2y/usbusx2yaudio.c
+++ b/sound/usb/usx2y/usbusx2yaudio.c
@@ -691,6 +691,8 @@ static int usX2Y_rate_set(struct usX2Yde
 			us->submitted =	2*NOOF_SETRATE_URBS;
 			for (i = 0; i < NOOF_SETRATE_URBS; ++i) {
 				struct urb *urb = us->urb[i];
+				if (!urb)
+					continue;
 				if (urb->status) {
 					if (!err)
 						err = -ENODEV;