[Bug 1882817] [NEW] Segfault in audio_pcm_sw_write with audio over VNC

[Bug 1882817] [NEW] Segfault in audio_pcm_sw_write with audio over VNC

[Artyom]

Public bug reported:

QEMU 5.0.0, built with ./configure --target-list=x86_64-softmmu
--enable-debug --disable-strip --disable-docs --disable-sdl

Running on a headless host (Ryzen 3600), Arch Linux, 64bit latest.
Guest is also Arch Linux, 64bit.

Started with qemu-system-x86_64 -vnc 0.0.0.0:0 -enable-kvm -m 4096 -cpu host -smp cores=2,threads=1,sockets=1 -machine q35 -vga std -device
 ich9-ahci,id=ahci -drive file=vm0.qcow2,format=qcow2,if=none,id=dsk0 -device ide-hd,drive=dsk0,bus=ahci.0 -soundhw hda

So, a headless VM is running on a server and is being connected to over
VNC. The virtual sound card is detected and speaker test is running
inside the VM. So far so good.

Then, i tell the VNC client to enable audio (QEMU Audio Client Message,
255,1,0). QEMU responds with a "stream is about to start" message (QEMU
Audio Server Message, 255,1,1) and then promptly crashes without sending
anything else.

Running it in GDB produces a crash at audio/audio.c:739

Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
audio_pcm_sw_write (sw=0x5555575bbf30, buf=0x0, size=1628) at audio/audio.c:739
739             if (!sw->hw->pcm_ops->volume_out) {

The exact sequence of events does not matter - i can enable sound before
playing anything, and then it would say nothing and keep working, but
crash with the same message once anything sound-playing is launched in
the VM.

Using different soundhw or adding various audiodev options does not seem
to affect anything.

I can't quite figure out if the QEMU Audio VNC extension is supposed to
work at all or not, but it would be handy to me if it is.

** Affects: qemu
     Importance: Undecided
         Status: New

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1882817

Title:
  Segfault in audio_pcm_sw_write with audio over VNC

Status in QEMU:
  New

Bug description:
  QEMU 5.0.0, built with ./configure --target-list=x86_64-softmmu
  --enable-debug --disable-strip --disable-docs --disable-sdl

  Running on a headless host (Ryzen 3600), Arch Linux, 64bit latest.
  Guest is also Arch Linux, 64bit.

  Started with qemu-system-x86_64 -vnc 0.0.0.0:0 -enable-kvm -m 4096 -cpu host -smp cores=2,threads=1,sockets=1 -machine q35 -vga std -device
   ich9-ahci,id=ahci -drive file=vm0.qcow2,format=qcow2,if=none,id=dsk0 -device ide-hd,drive=dsk0,bus=ahci.0 -soundhw hda

  So, a headless VM is running on a server and is being connected to
  over VNC. The virtual sound card is detected and speaker test is
  running inside the VM. So far so good.

  Then, i tell the VNC client to enable audio (QEMU Audio Client
  Message, 255,1,0). QEMU responds with a "stream is about to start"
  message (QEMU Audio Server Message, 255,1,1) and then promptly crashes
  without sending anything else.

  Running it in GDB produces a crash at audio/audio.c:739

  Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
  audio_pcm_sw_write (sw=0x5555575bbf30, buf=0x0, size=1628) at audio/audio.c:739
  739             if (!sw->hw->pcm_ops->volume_out) {

  The exact sequence of events does not matter - i can enable sound
  before playing anything, and then it would say nothing and keep
  working, but crash with the same message once anything sound-playing
  is launched in the VM.

  Using different soundhw or adding various audiodev options does not
  seem to affect anything.

  I can't quite figure out if the QEMU Audio VNC extension is supposed
  to work at all or not, but it would be handy to me if it is.

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1882817/+subscriptions

Re: [Bug 1882817] [NEW] Segfault in audio_pcm_sw_write with audio over VNC

[Philippe Mathieu-Daudé]

On 6/9/20 7:10 PM, Artyom wrote:
> Public bug reported:
> 
> QEMU 5.0.0, built with ./configure --target-list=x86_64-softmmu
> --enable-debug --disable-strip --disable-docs --disable-sdl
> 
> Running on a headless host (Ryzen 3600), Arch Linux, 64bit latest.
> Guest is also Arch Linux, 64bit.
> 
> Started with qemu-system-x86_64 -vnc 0.0.0.0:0 -enable-kvm -m 4096 -cpu host -smp cores=2,threads=1,sockets=1 -machine q35 -vga std -device
>  ich9-ahci,id=ahci -drive file=vm0.qcow2,format=qcow2,if=none,id=dsk0 -device ide-hd,drive=dsk0,bus=ahci.0 -soundhw hda
> 
> So, a headless VM is running on a server and is being connected to over
> VNC. The virtual sound card is detected and speaker test is running
> inside the VM. So far so good.
> 
> Then, i tell the VNC client to enable audio (QEMU Audio Client Message,
> 255,1,0). QEMU responds with a "stream is about to start" message (QEMU
> Audio Server Message, 255,1,1) and then promptly crashes without sending
> anything else.
> 
> Running it in GDB produces a crash at audio/audio.c:739
> 
> Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
> audio_pcm_sw_write (sw=0x5555575bbf30, buf=0x0, size=1628) at audio/audio.c:739
> 739             if (!sw->hw->pcm_ops->volume_out) {

Isn't it the one fixed by
https://www.mail-archive.com/qemu-devel@nongnu.org/msg705896.html?

> 
> The exact sequence of events does not matter - i can enable sound before
> playing anything, and then it would say nothing and keep working, but
> crash with the same message once anything sound-playing is launched in
> the VM.
> 
> Using different soundhw or adding various audiodev options does not seem
> to affect anything.
> 
> I can't quite figure out if the QEMU Audio VNC extension is supposed to
> work at all or not, but it would be handy to me if it is.
> 
> ** Affects: qemu
>      Importance: Undecided
>          Status: New
> 

Re: [Bug 1882817] [NEW] Segfault in audio_pcm_sw_write with audio over VNC

[Philippe Mathieu-Daudé]

On 6/9/20 7:10 PM, Artyom wrote:
> Public bug reported:
> 
> QEMU 5.0.0, built with ./configure --target-list=x86_64-softmmu
> --enable-debug --disable-strip --disable-docs --disable-sdl
> 
> Running on a headless host (Ryzen 3600), Arch Linux, 64bit latest.
> Guest is also Arch Linux, 64bit.
> 
> Started with qemu-system-x86_64 -vnc 0.0.0.0:0 -enable-kvm -m 4096 -cpu host -smp cores=2,threads=1,sockets=1 -machine q35 -vga std -device
>  ich9-ahci,id=ahci -drive file=vm0.qcow2,format=qcow2,if=none,id=dsk0 -device ide-hd,drive=dsk0,bus=ahci.0 -soundhw hda
> 
> So, a headless VM is running on a server and is being connected to over
> VNC. The virtual sound card is detected and speaker test is running
> inside the VM. So far so good.
> 
> Then, i tell the VNC client to enable audio (QEMU Audio Client Message,
> 255,1,0). QEMU responds with a "stream is about to start" message (QEMU
> Audio Server Message, 255,1,1) and then promptly crashes without sending
> anything else.
> 
> Running it in GDB produces a crash at audio/audio.c:739
> 
> Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
> audio_pcm_sw_write (sw=0x5555575bbf30, buf=0x0, size=1628) at audio/audio.c:739
> 739             if (!sw->hw->pcm_ops->volume_out) {

Isn't it the one fixed by
https://www.mail-archive.com/qemu-devel@nongnu.org/msg705896.html?

> 
> The exact sequence of events does not matter - i can enable sound before
> playing anything, and then it would say nothing and keep working, but
> crash with the same message once anything sound-playing is launched in
> the VM.
> 
> Using different soundhw or adding various audiodev options does not seem
> to affect anything.
> 
> I can't quite figure out if the QEMU Audio VNC extension is supposed to
> work at all or not, but it would be handy to me if it is.
> 
> ** Affects: qemu
>      Importance: Undecided
>          Status: New
>

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1882817

Title:
  Segfault in audio_pcm_sw_write with audio over VNC

Status in QEMU:
  New

Bug description:
  QEMU 5.0.0, built with ./configure --target-list=x86_64-softmmu
  --enable-debug --disable-strip --disable-docs --disable-sdl

  Running on a headless host (Ryzen 3600), Arch Linux, 64bit latest.
  Guest is also Arch Linux, 64bit.

  Started with qemu-system-x86_64 -vnc 0.0.0.0:0 -enable-kvm -m 4096 -cpu host -smp cores=2,threads=1,sockets=1 -machine q35 -vga std -device
   ich9-ahci,id=ahci -drive file=vm0.qcow2,format=qcow2,if=none,id=dsk0 -device ide-hd,drive=dsk0,bus=ahci.0 -soundhw hda

  So, a headless VM is running on a server and is being connected to
  over VNC. The virtual sound card is detected and speaker test is
  running inside the VM. So far so good.

  Then, i tell the VNC client to enable audio (QEMU Audio Client
  Message, 255,1,0). QEMU responds with a "stream is about to start"
  message (QEMU Audio Server Message, 255,1,1) and then promptly crashes
  without sending anything else.

  Running it in GDB produces a crash at audio/audio.c:739

  Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
  audio_pcm_sw_write (sw=0x5555575bbf30, buf=0x0, size=1628) at audio/audio.c:739
  739             if (!sw->hw->pcm_ops->volume_out) {

  The exact sequence of events does not matter - i can enable sound
  before playing anything, and then it would say nothing and keep
  working, but crash with the same message once anything sound-playing
  is launched in the VM.

  Using different soundhw or adding various audiodev options does not
  seem to affect anything.

  I can't quite figure out if the QEMU Audio VNC extension is supposed
  to work at all or not, but it would be handy to me if it is.

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1882817/+subscriptions

[Bug 1882817] Re: Segfault in audio_pcm_sw_write with audio over VNC

[Artyom]

Great.
Can confirm, that patch fixes it.

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1882817

Title:
  Segfault in audio_pcm_sw_write with audio over VNC

Status in QEMU:
  New

Bug description:
  QEMU 5.0.0, built with ./configure --target-list=x86_64-softmmu
  --enable-debug --disable-strip --disable-docs --disable-sdl

  Running on a headless host (Ryzen 3600), Arch Linux, 64bit latest.
  Guest is also Arch Linux, 64bit.

  Started with qemu-system-x86_64 -vnc 0.0.0.0:0 -enable-kvm -m 4096 -cpu host -smp cores=2,threads=1,sockets=1 -machine q35 -vga std -device
   ich9-ahci,id=ahci -drive file=vm0.qcow2,format=qcow2,if=none,id=dsk0 -device ide-hd,drive=dsk0,bus=ahci.0 -soundhw hda

  So, a headless VM is running on a server and is being connected to
  over VNC. The virtual sound card is detected and speaker test is
  running inside the VM. So far so good.

  Then, i tell the VNC client to enable audio (QEMU Audio Client
  Message, 255,1,0). QEMU responds with a "stream is about to start"
  message (QEMU Audio Server Message, 255,1,1) and then promptly crashes
  without sending anything else.

  Running it in GDB produces a crash at audio/audio.c:739

  Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
  audio_pcm_sw_write (sw=0x5555575bbf30, buf=0x0, size=1628) at audio/audio.c:739
  739             if (!sw->hw->pcm_ops->volume_out) {

  The exact sequence of events does not matter - i can enable sound
  before playing anything, and then it would say nothing and keep
  working, but crash with the same message once anything sound-playing
  is launched in the VM.

  Using different soundhw or adding various audiodev options does not
  seem to affect anything.

  I can't quite figure out if the QEMU Audio VNC extension is supposed
  to work at all or not, but it would be handy to me if it is.

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1882817/+subscriptions

[Bug 1882817] Re: Segfault in audio_pcm_sw_write with audio over VNC

[Philippe Mathieu-Daudé]

** Changed in: qemu
       Status: New => In Progress

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1882817

Title:
  Segfault in audio_pcm_sw_write with audio over VNC

Status in QEMU:
  In Progress

Bug description:
  QEMU 5.0.0, built with ./configure --target-list=x86_64-softmmu
  --enable-debug --disable-strip --disable-docs --disable-sdl

  Running on a headless host (Ryzen 3600), Arch Linux, 64bit latest.
  Guest is also Arch Linux, 64bit.

  Started with qemu-system-x86_64 -vnc 0.0.0.0:0 -enable-kvm -m 4096 -cpu host -smp cores=2,threads=1,sockets=1 -machine q35 -vga std -device
   ich9-ahci,id=ahci -drive file=vm0.qcow2,format=qcow2,if=none,id=dsk0 -device ide-hd,drive=dsk0,bus=ahci.0 -soundhw hda

  So, a headless VM is running on a server and is being connected to
  over VNC. The virtual sound card is detected and speaker test is
  running inside the VM. So far so good.

  Then, i tell the VNC client to enable audio (QEMU Audio Client
  Message, 255,1,0). QEMU responds with a "stream is about to start"
  message (QEMU Audio Server Message, 255,1,1) and then promptly crashes
  without sending anything else.

  Running it in GDB produces a crash at audio/audio.c:739

  Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
  audio_pcm_sw_write (sw=0x5555575bbf30, buf=0x0, size=1628) at audio/audio.c:739
  739             if (!sw->hw->pcm_ops->volume_out) {

  The exact sequence of events does not matter - i can enable sound
  before playing anything, and then it would say nothing and keep
  working, but crash with the same message once anything sound-playing
  is launched in the VM.

  Using different soundhw or adding various audiodev options does not
  seem to affect anything.

  I can't quite figure out if the QEMU Audio VNC extension is supposed
  to work at all or not, but it would be handy to me if it is.

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1882817/+subscriptions

[Bug 1882817] Re: Segfault in audio_pcm_sw_write with audio over VNC

[Philippe Mathieu-Daudé]

commit cbaf25d1f59ee13fc7542a06ea70784f2e000c04.

** Changed in: qemu
       Status: In Progress => Fix Committed

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1882817

Title:
  Segfault in audio_pcm_sw_write with audio over VNC

Status in QEMU:
  Fix Committed

Bug description:
  QEMU 5.0.0, built with ./configure --target-list=x86_64-softmmu
  --enable-debug --disable-strip --disable-docs --disable-sdl

  Running on a headless host (Ryzen 3600), Arch Linux, 64bit latest.
  Guest is also Arch Linux, 64bit.

  Started with qemu-system-x86_64 -vnc 0.0.0.0:0 -enable-kvm -m 4096 -cpu host -smp cores=2,threads=1,sockets=1 -machine q35 -vga std -device
   ich9-ahci,id=ahci -drive file=vm0.qcow2,format=qcow2,if=none,id=dsk0 -device ide-hd,drive=dsk0,bus=ahci.0 -soundhw hda

  So, a headless VM is running on a server and is being connected to
  over VNC. The virtual sound card is detected and speaker test is
  running inside the VM. So far so good.

  Then, i tell the VNC client to enable audio (QEMU Audio Client
  Message, 255,1,0). QEMU responds with a "stream is about to start"
  message (QEMU Audio Server Message, 255,1,1) and then promptly crashes
  without sending anything else.

  Running it in GDB produces a crash at audio/audio.c:739

  Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
  audio_pcm_sw_write (sw=0x5555575bbf30, buf=0x0, size=1628) at audio/audio.c:739
  739             if (!sw->hw->pcm_ops->volume_out) {

  The exact sequence of events does not matter - i can enable sound
  before playing anything, and then it would say nothing and keep
  working, but crash with the same message once anything sound-playing
  is launched in the VM.

  Using different soundhw or adding various audiodev options does not
  seem to affect anything.

  I can't quite figure out if the QEMU Audio VNC extension is supposed
  to work at all or not, but it would be handy to me if it is.

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1882817/+subscriptions

[Bug 1882817] Re: Segfault in audio_pcm_sw_write with audio over VNC

[Thomas Huth]

** Changed in: qemu
       Status: Fix Committed => Fix Released

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1882817

Title:
  Segfault in audio_pcm_sw_write with audio over VNC

Status in QEMU:
  Fix Released

Bug description:
  QEMU 5.0.0, built with ./configure --target-list=x86_64-softmmu
  --enable-debug --disable-strip --disable-docs --disable-sdl

  Running on a headless host (Ryzen 3600), Arch Linux, 64bit latest.
  Guest is also Arch Linux, 64bit.

  Started with qemu-system-x86_64 -vnc 0.0.0.0:0 -enable-kvm -m 4096 -cpu host -smp cores=2,threads=1,sockets=1 -machine q35 -vga std -device
   ich9-ahci,id=ahci -drive file=vm0.qcow2,format=qcow2,if=none,id=dsk0 -device ide-hd,drive=dsk0,bus=ahci.0 -soundhw hda

  So, a headless VM is running on a server and is being connected to
  over VNC. The virtual sound card is detected and speaker test is
  running inside the VM. So far so good.

  Then, i tell the VNC client to enable audio (QEMU Audio Client
  Message, 255,1,0). QEMU responds with a "stream is about to start"
  message (QEMU Audio Server Message, 255,1,1) and then promptly crashes
  without sending anything else.

  Running it in GDB produces a crash at audio/audio.c:739

  Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
  audio_pcm_sw_write (sw=0x5555575bbf30, buf=0x0, size=1628) at audio/audio.c:739
  739             if (!sw->hw->pcm_ops->volume_out) {

  The exact sequence of events does not matter - i can enable sound
  before playing anything, and then it would say nothing and keep
  working, but crash with the same message once anything sound-playing
  is launched in the VM.

  Using different soundhw or adding various audiodev options does not
  seem to affect anything.

  I can't quite figure out if the QEMU Audio VNC extension is supposed
  to work at all or not, but it would be handy to me if it is.

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1882817/+subscriptions