On Fri, 03 Nov 2017 20:52:49 +0100, Takashi Iwai wrote:
On Fri, 03 Nov 2017 15:44:59 +0100, Andrey Konovalov wrote:
Hi!
I've got the following report while fuzzing the kernel with syzkaller.
On commit 3a99df9a3d14cd866b5516f8cba515a3bfd554ab (4.14-rc7+).
Looks like there's no check for the actual endpoint types.
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 Modules linked in: CPU: 0 PID: 24 Comm: kworker/0:1 Not tainted 4.14.0-rc7-44290-gf28444df2601-dirty #52 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Workqueue: usb_hub_wq hub_event task: ffff88006bef5c00 task.stack: ffff88006bf60000 RIP: 0010:usb_submit_urb+0x113e/0x1400 drivers/usb/core/urb.c:470 RSP: 0018:ffff88006bf67440 EFLAGS: 00010286 RAX: 0000000000000029 RBX: ffff880064698c80 RCX: ffffffff812495b5 RDX: 0000000000000000 RSI: ffffffff8124d76a RDI: 0000000000000005 RBP: ffff88006bf674b0 R08: ffff88006bef5c00 R09: 0000000000000006 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000003 R14: ffff880069a25a20 R15: ffff880064698d04 FS: 0000000000000000(0000) GS:ffff88006ca00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe6fdba3000 CR3: 0000000068470000 CR4: 00000000000006f0 Call Trace: usb_stream_start+0x48a/0x9f0 sound/usb/usx2y/usb_stream.c:690 us122l_start+0x116/0x290 sound/usb/usx2y/us122l.c:365
(snip)
OK, so this looks like another typical issue. A totally untested patch is below. Could you check whether it covers?
FYI, below is the patch with a proper description that I queued to for-next branch.
Takashi
-- 8< -- From: Takashi Iwai tiwai@suse.de Subject: [PATCH] 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 Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/usb/usx2y/usb_stream.c | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-)
diff --git a/sound/usb/usx2y/usb_stream.c b/sound/usb/usx2y/usb_stream.c index e229abd21652..b0f8979ff2d2 100644 --- a/sound/usb/usx2y/usb_stream.c +++ b/sound/usb/usx2y/usb_stream.c @@ -56,7 +56,7 @@ static void playback_prep_freqn(struct usb_stream_kernel *sk, struct urb *urb) 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;