ALSA: usx2y: Fix potential NULL dereference

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@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200420075529.27203-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/sound/usb/usx2y/usbusx2yaudio.c b/sound/usb/usx2y/usbusx2yaudio.c
index f93b355756e6027e694257c0e2ab829767c7be98..2dfc0abf2e37310e6df192cedced4db0e94494e4 100644 (file)
--- a/sound/usb/usx2y/usbusx2yaudio.c
+++ b/sound/usb/usx2y/usbusx2yaudio.c
@@ -689,6 +689,8 @@ static int usX2Y_rate_set(struct usX2Ydev *usX2Y, int rate)
                        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;