ALSA: usx2y: Fix invalid stream URBs

The us122l driver creates URBs per the fixed endpoints, and this may
end up with URBs with inconsistent pipes when a fuzzer or a malicious
program deals with the manipulated endpoints.  It ends up with a
kernel warning like:

  usb 1-1: BOGUS urb xfer, pipe 0 != type 3
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 24 at drivers/usb/core/urb.c:471
  usb_submit_urb+0x113e/0x1400
  Call Trace:
   usb_stream_start+0x48a/0x9f0 sound/usb/usx2y/usb_stream.c:690
   us122l_start+0x116/0x290 sound/usb/usx2y/us122l.c:365
   us122l_create_card sound/usb/usx2y/us122l.c:502
   us122l_usb_probe sound/usb/usx2y/us122l.c:588
   ....

For avoiding the bad access, this patch adds a few sanity checks of
the validity of created URBs like previous similar fixes using the new
usb_urb_ep_type_check() helper function.

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/usb/usx2y/usb_stream.c b/sound/usb/usx2y/usb_stream.c
index e229abd..b0f8979 100644 (file)
--- a/sound/usb/usx2y/usb_stream.c
+++ b/sound/usb/usx2y/usb_stream.c
@@ -56,7 +56,7 @@ check:
                    lb, s->period_size);
 }
 
-static void init_pipe_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
+static int init_pipe_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
                           struct urb **urbs, char *transfer,
                           struct usb_device *dev, int pipe)
 {
@@ -77,6 +77,8 @@ static void init_pipe_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
                urb->interval = 1;
                if (usb_pipeout(pipe))
                        continue;
+               if (usb_urb_ep_type_check(urb))
+                       return -EINVAL;
 
                urb->transfer_buffer_length = transfer_length;
                desc = urb->iso_frame_desc;
@@ -87,9 +89,11 @@ static void init_pipe_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
                        desc[p].length = maxpacket;
                }
        }
+
+       return 0;
 }
 
-static void init_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
+static int init_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
                      struct usb_device *dev, int in_pipe, int out_pipe)
 {
        struct usb_stream       *s = sk->s;
@@ -103,9 +107,12 @@ static void init_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
                sk->outurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
        }
 
-       init_pipe_urbs(sk, use_packsize, sk->inurb, indata, dev, in_pipe);
-       init_pipe_urbs(sk, use_packsize, sk->outurb, sk->write_page, dev,
-                      out_pipe);
+       if (init_pipe_urbs(sk, use_packsize, sk->inurb, indata, dev, in_pipe) ||
+           init_pipe_urbs(sk, use_packsize, sk->outurb, sk->write_page, dev,
+                          out_pipe))
+               return -EINVAL;
+
+       return 0;
 }
 
 
@@ -226,7 +233,11 @@ struct usb_stream *usb_stream_new(struct usb_stream_kernel *sk,
        else
                sk->freqn = get_usb_high_speed_rate(sample_rate);
 
-       init_urbs(sk, use_packsize, dev, in_pipe, out_pipe);
+       if (init_urbs(sk, use_packsize, dev, in_pipe, out_pipe) < 0) {
+               usb_stream_free(sk);
+               return NULL;
+       }
+
        sk->s->state = usb_stream_stopped;
 out:
        return sk->s;