Re: [PATCH v2] hw/audio/sb16: Avoid assertion by restricting I/O sampling rate range

[Gerd Hoffmann <kraxel@redhat.com>]

On Wed, Jun 16, 2021 at 12:43:49PM +0200, Philippe Mathieu-Daudé wrote:
> While the SB16 seems to work up to 48000 Hz, the "Sound Blaster Series
> Hardware Programming Guide" limit the sampling range from 4000 Hz to
> 44100 Hz (Section 3-9, 3-10: Digitized Sound I/O Programming, tables
> 3-2 and 3-3).
> 
> Later, section 6-15 (DSP Commands) is more specific regarding the 41h /
> 42h registers (Set digitized sound output sampling rate):
> 
>   Valid sampling rates range from 5000 to 45000 Hz inclusive.
> 
> There is no comment regarding error handling if the register is filled
> with an out-of-range value.  (See also section 3-28 "8-bit or 16-bit
> Auto-initialize Transfer"). Assume limits are enforced in hardware.
> 
> This fixes triggering an assertion in audio_calloc():
> 
>   #1 abort
>   #2 audio_bug audio/audio.c:119:9
>   #3 audio_calloc audio/audio.c:154:9
>   #4 audio_pcm_sw_alloc_resources_out audio/audio_template.h:116:15
>   #5 audio_pcm_sw_init_out audio/audio_template.h:175:11
>   #6 audio_pcm_create_voice_pair_out audio/audio_template.h:410:9
>   #7 AUD_open_out audio/audio_template.h:503:14
>   #8 continue_dma8 hw/audio/sb16.c:216:20
>   #9 dma_cmd8 hw/audio/sb16.c:276:5
>   #10 command hw/audio/sb16.c:0
>   #11 dsp_write hw/audio/sb16.c:949:13
>   #12 portio_write softmmu/ioport.c:205:13
>   #13 memory_region_write_accessor softmmu/memory.c:491:5
>   #14 access_with_adjusted_size softmmu/memory.c:552:18
>   #15 memory_region_dispatch_write softmmu/memory.c:0:13
>   #16 flatview_write_continue softmmu/physmem.c:2759:23
>   #17 flatview_write softmmu/physmem.c:2799:14
>   #18 address_space_write softmmu/physmem.c:2891:18
>   #19 cpu_outw softmmu/ioport.c:70:5
> 
> [*] http://www.baudline.com/solutions/full_duplex/sb16_pci/index.html
> 
> Fixes: 85571bc7415 ("audio merge (malc)")
> Buglink: https://bugs.launchpad.net/bugs/1910603
> OSS-Fuzz Report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=29174
> Tested-by: Qiang Liu <cyruscyliu@gmail.com>
> Reviewed-by: Qiang Liu <cyruscyliu@gmail.com>
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

Added to audio queue.

thanks,
  Gerd