ALSA: usb-audio: Fix NULL dereference in create_fixed_stream_quirk()
create_fixed_stream_quirk() may cause a NULL-pointer dereference by
accessing the non-existing endpoint when a USB device with a malformed
USB descriptor is used.
This patch avoids it simply by adding a sanity check of bNumEndpoints
before the accesses.
Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=971125
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 5b03296..529c35c 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -180,6 +180,12 @@
}
alts = &iface->altsetting[fp->altset_idx];
altsd = get_iface_desc(alts);
+ if (altsd->bNumEndpoints < 1) {
+ kfree(fp);
+ kfree(rate_table);
+ return -EINVAL;
+ }
+
fp->protocol = altsd->bInterfaceProtocol;
if (fp->datainterval == 0)
