ALSA: usb-audio: Fix NULL dereference in create_fixed_stream_quirk()
authorTakashi Iwai <tiwai@suse.de>
Tue, 15 Mar 2016 11:09:10 +0000 (12:09 +0100)
committerTakashi Iwai <tiwai@suse.de>
Wed, 16 Mar 2016 11:42:16 +0000 (12:42 +0100)
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>
sound/usb/quirks.c

index 5b03296a5bd9ef4977d22f0d026157b76553a1ab..529c35cceaa6f37ffc56a9f8fa69ebcaea1b3603 100644 (file)
@@ -180,6 +180,12 @@ static int create_fixed_stream_quirk(struct snd_usb_audio *chip,
        }
        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)