回复: WARNING in submit_audio_out_urb/usb_submit_urb

Fri Jul 10 15:33:51 CEST 2020

On Fri, 10 Jul 2020 10:38:31 +0200,
Takashi Iwai wrote:
> 
> On Fri, 10 Jul 2020 10:12:43 +0200,
> Zhang, Qiang wrote:
> > 
> > 
> > 
> > ________________________________________
> > 发件人: linux-kernel-owner at vger.kernel.org <linux-kernel-owner at vger.kernel.org> 代表 syzbot <syzbot+c190f6858a04ea7fbc52 at syzkaller.appspotmail.com>
> > 发送时间: 2020年7月9日 21:34
> > 收件人: andreyknvl at google.com; gregkh at linuxfoundation.org; ingrassia at epigenesys.com; linux-kernel at vger.kernel.org; linux-usb at vger.kernel.org; syzkaller-bugs at googlegroups.com
> > 主题: WARNING in submit_audio_out_urb/usb_submit_urb
> > 
> > Hello,
> > 
> > syzbot found the following crash on:
> > 
> > HEAD commit:    768a0741 usb: dwc2: gadget: Remove assigned but never used..
> > git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
> > console output: https://syzkaller.appspot.com/x/log.txt?x=1568d11f100000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=999be4eb2478ffa5
> > dashboard link: https://syzkaller.appspot.com/bug?extid=c190f6858a04ea7fbc52
> > compiler:       gcc (GCC) 10.1.0-syz 20200507
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=123aa2fb100000
> > 
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+c190f6858a04ea7fbc52 at syzkaller.appspotmail.com
> > 
> > usb 1-1: send failed (error -32)
> > snd_usb_toneport 1-1:0.0: Line 6 TonePort GX now attached
> > ------------[ cut here ]------------
> > usb 1-1: BOGUS urb xfer, pipe 0 != type 3
> > WARNING: CPU: 0 PID: 12 at drivers/usb/core/urb.c:478 usb_submit_urb+0xa17/0x13e0 drivers/usb/core/urb.c:478
> > Kernel panic - not syncing: panic_on_warn set ...
> > CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.8.0-rc3-syzkaller #0
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> > Workqueue: events line6_startup_work
> > Call Trace:
> >  __dump_stack lib/dump_stack.c:77 [inline]
> >  dump_stack+0xf6/0x16e lib/dump_stack.c:118
> >  panic+0x2aa/0x6e1 kernel/panic.c:231
> >  __warn.cold+0x20/0x50 kernel/panic.c:600
> >  report_bug+0x1bd/0x210 lib/bug.c:198
> >  handle_bug+0x41/0x80 arch/x86/kernel/traps.c:235
> >  exc_invalid_op+0x13/0x40 arch/x86/kernel/traps.c:255
> >  asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:563
> > RIP: 0010:usb_submit_urb+0xa17/0x13e0 drivers/usb/core/urb.c:478
> > Code: 84 e7 04 00 00 e8 a9 10 ca fd 4c 89 ef e8 41 79 12 ff 41 89 d8 44 89 e1 4c 89 f2 48 89 c6 48 c7 c7 80 a0 5d 86 e8 db 77 9e fd <0f> 0b e8 82 10 ca fd 0f b6 6c 24 08 48 c7 c6 e0 a1 5d 86 48 89 ef
> > RSP: 0018:ffff8881da227b10 EFLAGS: 00010086
> > RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
> > RDX: ffff8881da211900 RSI: ffffffff8129b4e3 RDI: ffffed103b444f54
> > RBP: 0000000000000030 R08: 0000000000000001 R09: ffff8881db21fe8b
> > R10: 0000000000000000 R11: 0000000000000004 R12: 0000000000000000
> > R13: ffff8881d6ecd0a0 R14: ffff8881d3d8c690 R15: ffff8881d54c4000
> >  submit_audio_out_urb+0x6d6/0x1a00 sound/usb/line6/playback.c:271
> >  line6_submit_audio_out_all_urbs+0xc9/0x120 sound/usb/line6/playback.c:291
> >  line6_stream_start+0x187/0x230 sound/usb/line6/pcm.c:195
> >  line6_pcm_acquire+0x137/0x210 sound/usb/line6/pcm.c:318
> >  line6_startup_work+0x42/0x50 sound/usb/line6/driver.c:734
> >  process_one_work+0x94c/0x15f0 kernel/workqueue.c:2269
> >  worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
> >  kthread+0x392/0x470 kernel/kthread.c:291
> >  ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
> > 
> >  It's like Alan Stern's reply to the email titled "KASAN: use-after-free Read in line6_submit_audio_in_all_urbs."   It's also like a problem with asynchronous operations. can replace "cancel_delayed_work" with" cancel_delayed_work_sync"
> > in "line6_disconnect" func？
> 
> No, this looks a different problem.  It's just a matter of the missing
> URB type check that leads to a USB warning.  A typical issue with the
> USB fuzzing.
> 
> I'll check it later.

... and below is the fix patch.


Takashi

-- 8< --
From: Takashi Iwai <tiwai at suse.de>
Subject: [PATCH] ALSA: line6: Perform sanity check for each URB creation

LINE6 drivers create stream URBs with a fixed pipe without checking
its validity, and this may lead to a kernel WARNING at the submission
when a malformed USB descriptor is passed.

For avoiding the kernel warning, perform the similar sanity checks for
each pipe type at creating a URB.

Reported-by: syzbot+c190f6858a04ea7fbc52 at syzkaller.appspotmail.com
Cc: <stable at vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/usb/line6/capture.c  | 2 ++
 sound/usb/line6/playback.c | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/sound/usb/line6/capture.c b/sound/usb/line6/capture.c
index 663d608c4287..970c9bdce0b2 100644
--- a/sound/usb/line6/capture.c
+++ b/sound/usb/line6/capture.c
@@ -286,6 +286,8 @@ int line6_create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
 		urb->interval = LINE6_ISO_INTERVAL;
 		urb->error_count = 0;
 		urb->complete = audio_in_callback;
+		if (usb_urb_ep_type_check(urb))
+			return -EINVAL;
 	}
 
 	return 0;
diff --git a/sound/usb/line6/playback.c b/sound/usb/line6/playback.c
index 01930ce7bd75..8233c61e23f1 100644
--- a/sound/usb/line6/playback.c
+++ b/sound/usb/line6/playback.c
@@ -431,6 +431,8 @@ int line6_create_audio_out_urbs(struct snd_line6_pcm *line6pcm)
 		urb->interval = LINE6_ISO_INTERVAL;
 		urb->error_count = 0;
 		urb->complete = audio_out_callback;
+		if (usb_urb_ep_type_check(urb))
+			return -EINVAL;
 	}
 
 	return 0;
-- 
2.16.4

