Segfault due to audio driver

[06b7e]

Windows guest is crashing within minutes after starting. The crash is reproducible on Ubuntu 18.10 and 19.04 (daily build). Also reproducible in current test build of virtualbox. Issue occurs when:

1. Audio output is enabled and host driver / audio controller combination results in valid sound within guest os.
2. Virtualbox guest additions are installed.

Audio input does not seem to effect the problem. Disabling microphone in hard- or software has no difference.

Logs:

Output in syslog:

Mar 15 15:37:32 m-7223 kernel: [ 3061.086031] EMT-3[28881]: segfault at 7f4a46dfcfec ip 00007f4a8b7b9594 sp 00007f4a46efb8c8 error 4 in libc-2.29.so[7f4a8b655000+173000]
Mar 15 15:37:32 m-7223 kernel: [ 3061.086048] Code: 0e 88 0f c3 c5 fa 6f 06 c5 fa 6f 4c 16 f0 c5 fa 7f 07 c5 fa 7f 4c 17 f0 c3 48 8b 4c 16 f8 48 8b 36 48 89 4c 17 f8 48 89 37 c3 <8b> 4c 16 fc 8b 36 89 4c 17 fc 89 37 c3 0f b7 4c 16 fe 0f b7 36 66

No relevant log in (guest) windows event viewer. Audio debug logs and VBox.log are attached.

[06b7e]

Debug streams : ​https://drive.google.com/file/d/1vu-KZ2l_HXhKeWLK31xoLsYqFpo-4LhH/view?usp=sharing

Notice the sound in the last 3 seconds - this consistently appears before each crash.

[pentagonik]

Can you please try providing a core dump of the VirtualBox VM process when this segfault is happening? We have a Wiki page here explaining how to do this. Thanks!

[06b7e]

Here is a fresh CoreDump from Virtualbox 6.0.4 r128413: ​https://drive.google.com/file/d/1kBkVHdMF_3KhPkPv9jxqmyHtB-7YoN--/view?usp=sharing

[pentagonik]

Thank you -- I'll have a look.

[pentagonik]

I just had a quick peek at the core dump provided, and it seems that the crash occurred when restoring from a saved state with the HDA device emulation -- is that correct? Which audio backend is being used (PulseAudio / ALSA / ...)?

Can you please also provide a verbose audio log file, as described here? Thanks!

[efferre]

I am also experiencing a problem of audio driver segfault when starting a guest WindowsXP machine. On the Linux host I am using pulseaudio, during startup the virtual machine is stopped crashing. By using dmesg I get the following info:

[ 7733.140657] EMT[8825]: segfault at 0 ip 00007fdd8991d9bc sp 00007fdda8f566c0 error 4 in VBoxDD.so[7fdd897f6000+150000]
[ 7733.140664] Code: 45 89 f9 4d 89 f0 48 8d 0d 21 5d 06 00 ba 61 00 00 00 be 10 00 00 00 31 c0 e8 20 a9 ed ff 4c 89 e7 e8 68 13 00 00 48 8b 4d c8 <f3> 0f 6f 00 41 0f 11 45 24 8b 40 10 89 41 10 4d 89 65 10 48 8b 7b

I am attaching the log with audio debug enabled.

[efferre]

virtual machine log with audio debug enabled

[pentagonik]

Thanks for the log -- does your VM perform any recording when the crash is happening? Does your host have any input devices (microphone etc) attached and in a working state?

[efferre]

The VM is crashing at boot, no recording is done. I have available three input audio devices, one from the audio sound card, one from the webcam and last from an usb port extender recycled from an old laptop.

$ pacmd list-sources | grep -e 'index:' -e device.string -e 'name:'

index: 0

name: <alsa_output.pci-0000_00_1b.0.analog-stereo.monitor>

device.string = "0"

index: 1

name: <alsa_input.pci-0000_00_1b.0.analog-stereo>

device.string = "front:0"

• index: 2

name: <alsa_input.usb-046d_089d-01.analog-mono>

device.string = "hw:2"

index: 3

name: <alsa_output.usb-0d8c_USB_Audio-00.analog-surround-71.monitor>

device.string = "3"

index: 4

name: <alsa_input.usb-0d8c_USB_Audio-00.analog-stereo>

device.string = "front:3"