Thx. I learned a lot about contributing to QEMU from this discussion! Best, Qiang
On Wed, Jun 16, 2021 at 6:43 PM Philippe Mathieu-Daudé <f4...@amsat.org> 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 <cyruscy...@gmail.com> > Reviewed-by: Qiang Liu <cyruscy...@gmail.com> > Signed-off-by: Philippe Mathieu-Daudé <f4...@amsat.org> > --- > v2: Added Qiang Liu's T-b/R-b tags ¯\_(ツ)_/¯ > --- > hw/audio/sb16.c | 14 ++++++++++ > tests/qtest/fuzz-sb16-test.c | 52 ++++++++++++++++++++++++++++++++++++ > MAINTAINERS | 1 + > tests/qtest/meson.build | 1 + > 4 files changed, 68 insertions(+) > create mode 100644 tests/qtest/fuzz-sb16-test.c > > diff --git a/hw/audio/sb16.c b/hw/audio/sb16.c > index 8b207004102..5cf121fe363 100644 > --- a/hw/audio/sb16.c > +++ b/hw/audio/sb16.c > @@ -115,6 +115,9 @@ struct SB16State { > PortioList portio_list; > }; > > +#define SAMPLE_RATE_MIN 5000 > +#define SAMPLE_RATE_MAX 45000 > + > static void SB_audio_callback (void *opaque, int free); > > static int magic_of_irq (int irq) > @@ -241,6 +244,17 @@ static void dma_cmd8 (SB16State *s, int mask, int > dma_len) > int tmp = (256 - s->time_const); > s->freq = (1000000 + (tmp / 2)) / tmp; > } > + if (s->freq < SAMPLE_RATE_MIN) { > + qemu_log_mask(LOG_GUEST_ERROR, > + "sampling range too low: %d, increasing to %u\n", > + s->freq, SAMPLE_RATE_MIN); > + s->freq = SAMPLE_RATE_MIN; > + } else if (s->freq > SAMPLE_RATE_MAX) { > + qemu_log_mask(LOG_GUEST_ERROR, > + "sampling range too high: %d, decreasing to %u\n", > + s->freq, SAMPLE_RATE_MAX); > + s->freq = SAMPLE_RATE_MAX; > + } > > if (dma_len != -1) { > s->block_size = dma_len << s->fmt_stereo; > diff --git a/tests/qtest/fuzz-sb16-test.c b/tests/qtest/fuzz-sb16-test.c > new file mode 100644 > index 00000000000..51030cd7dc4 > --- /dev/null > +++ b/tests/qtest/fuzz-sb16-test.c > @@ -0,0 +1,52 @@ > +/* > + * QTest fuzzer-generated testcase for sb16 audio device > + * > + * Copyright (c) 2021 Philippe Mathieu-Daudé <f4...@amsat.org> > + * > + * SPDX-License-Identifier: GPL-2.0-or-later > + */ > + > +#include "qemu/osdep.h" > +#include "libqos/libqtest.h" > + > +/* > + * This used to trigger the assert in audio_calloc > + * https://bugs.launchpad.net/qemu/+bug/1910603 > + */ > +static void test_fuzz_sb16_0x1c(void) > +{ > + QTestState *s = qtest_init("-M q35 -display none " > + "-device sb16,audiodev=snd0 " > + "-audiodev none,id=snd0"); > + qtest_outw(s, 0x22c, 0x41); > + qtest_outb(s, 0x22c, 0x00); > + qtest_outw(s, 0x22c, 0x1004); > + qtest_outw(s, 0x22c, 0x001c); > + qtest_quit(s); > +} > + > +static void test_fuzz_sb16_0x91(void) > +{ > + QTestState *s = qtest_init("-M pc -display none " > + "-device sb16,audiodev=none " > + "-audiodev id=none,driver=none"); > + qtest_outw(s, 0x22c, 0xf141); > + qtest_outb(s, 0x22c, 0x00); > + qtest_outb(s, 0x22c, 0x24); > + qtest_outb(s, 0x22c, 0x91); > + qtest_quit(s); > +} > + > +int main(int argc, char **argv) > +{ > + const char *arch = qtest_get_arch(); > + > + g_test_init(&argc, &argv, NULL); > + > + if (strcmp(arch, "i386") == 0) { > + qtest_add_func("fuzz/test_fuzz_sb16/1c", test_fuzz_sb16_0x1c); > + qtest_add_func("fuzz/test_fuzz_sb16/91", test_fuzz_sb16_0x91); > + } > + > + return g_test_run(); > +} > diff --git a/MAINTAINERS b/MAINTAINERS > index 7d9cd290426..d619ea8fcd1 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -2221,6 +2221,7 @@ F: qapi/audio.json > F: tests/qtest/ac97-test.c > F: tests/qtest/es1370-test.c > F: tests/qtest/intel-hda-test.c > +F: tests/qtest/fuzz-sb16-test.c > > Block layer core > M: Kevin Wolf <kw...@redhat.com> > diff --git a/tests/qtest/meson.build b/tests/qtest/meson.build > index c3a223a83d6..b03e8541700 100644 > --- a/tests/qtest/meson.build > +++ b/tests/qtest/meson.build > @@ -20,6 +20,7 @@ > qtests_generic = \ > (config_all_devices.has_key('CONFIG_MEGASAS_SCSI_PCI') ? > ['fuzz-megasas-test'] : []) + \ > (config_all_devices.has_key('CONFIG_VIRTIO_SCSI') ? > ['fuzz-virtio-scsi-test'] : []) + \ > + (config_all_devices.has_key('CONFIG_SB16') ? ['fuzz-sb16-test'] : []) + \ > [ > 'cdrom-test', > 'device-introspect-test', > -- > 2.31.1 >
