The I/O sampling rate range is enforced to 5000 to 45000HZ according to
commit a2cd86a9. Setting I/O sampling rate with command 41h/42h, a guest
user can break this assumption and trigger an assertion in audio_calloc
via command 0xd4. This patch restricts the I/O sampling rate range for
command 41h/42h.
Fixes: 85571bc741 ("audio merge (malc)")
Signed-off-by: Qiang Liu <cyruscyliu@gmail.com>
Message-Id: <1624502687-5214-1-git-send-email-cyruscyliu@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
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
OSS-Fuzz Report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=29174
Fixes: 85571bc741 ("audio merge (malc)")
Buglink: https://bugs.launchpad.net/bugs/1910603
Tested-by: Qiang Liu <cyruscyliu@gmail.com>
Reviewed-by: Qiang Liu <cyruscyliu@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210616104349.2398060-1-f4bug@amsat.org>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Qiang Liu