On Thu, Apr 4, 2024 at 10:55 AM Philippe Mathieu-Daudé
<phi...@linaro.org> wrote:
>
> Per "SD Host Controller Standard Specification Version 3.00":
>
> * 1.7 Buffer Control
>
> - 1.7.1 Control of Buffer Pointer
>
> (3) Buffer Control with Block Size
>
> In case of write operation, the buffer accumulates the data
> written through the Buffer Data Port register. When the buffer
> pointer reaches the block size, Buffer Write Enable in the
> Present State register changes 1 to 0. It means no more data
> can be written to the buffer. Excess data of the last write is
> ignored. For example, if just lower 2 bytes data can be written
> to the buffer and a 32-bit (4-byte) block of data is written to
> the Buffer Data Port register, the lower 2 bytes of data is
> written to the buffer and the upper 2 bytes is ignored.
>
> Discard the excess of data to avoid overflow reported by fuzzer:
>
> $ cat << EOF | qemu-system-i386 \
> -display none -nodefaults \
> -machine accel=qtest -m 512M \
> -device sdhci-pci,sd-spec-version=3 \
> -device sd-card,drive=mydrive \
> -drive
> if=none,index=0,file=null-co://,format=raw,id=mydrive -nographic \
> -qtest stdio
> outl 0xcf8 0x80001013
> outl 0xcfc 0x91
> outl 0xcf8 0x80001001
> outl 0xcfc 0x06000000
> write 0x9100002c 0x1 0x05
> write 0x91000058 0x1 0x16
> write 0x91000005 0x1 0x04
> write 0x91000028 0x1 0x08
> write 0x16 0x1 0x21
> write 0x19 0x1 0x20
> write 0x9100000c 0x1 0x01
> write 0x9100000e 0x1 0x20
> write 0x9100000f 0x1 0x00
> write 0x9100000c 0x1 0x00
> write 0x91000020 0x1 0x00
> EOF
>
> Stack trace (part):
> =================================================================
> ==89993==ERROR: AddressSanitizer: heap-buffer-overflow on address
> 0x615000029900 at pc 0x55d5f885700d bp 0x7ffc1e1e9470 sp 0x7ffc1e1e9468
> WRITE of size 1 at 0x615000029900 thread T0
> #0 0x55d5f885700c in sdhci_write_dataport hw/sd/sdhci.c:564:39
> #1 0x55d5f8849150 in sdhci_write hw/sd/sdhci.c:1223:13
> #2 0x55d5fa01db63 in memory_region_write_accessor system/memory.c:497:5
> #3 0x55d5fa01d245 in access_with_adjusted_size system/memory.c:573:18
> #4 0x55d5fa01b1a9 in memory_region_dispatch_write system/memory.c:1521:16
> #5 0x55d5fa09f5c9 in flatview_write_continue system/physmem.c:2711:23
> #6 0x55d5fa08f78b in flatview_write system/physmem.c:2753:12
> #7 0x55d5fa08f258 in address_space_write system/physmem.c:2860:18
> ...
> 0x615000029900 is located 0 bytes to the right of 512-byte region
> [0x615000029700,0x615000029900) allocated by thread T0 here:
> #0 0x55d5f7237b27 in __interceptor_calloc
> #1 0x7f9e36dd4c50 in g_malloc0
> #2 0x55d5f88672f7 in sdhci_pci_realize hw/sd/sdhci-pci.c:36:5
> #3 0x55d5f844b582 in pci_qdev_realize hw/pci/pci.c:2092:9
> #4 0x55d5fa2ee74b in device_set_realized hw/core/qdev.c:510:13
> #5 0x55d5fa325bfb in property_set_bool qom/object.c:2358:5
> #6 0x55d5fa31ea45 in object_property_set qom/object.c:1472:5
> #7 0x55d5fa332509 in object_property_set_qobject om/qom-qobject.c:28:10
> #8 0x55d5fa31f6ed in object_property_set_bool qom/object.c:1541:15
> #9 0x55d5fa2e2948 in qdev_realize hw/core/qdev.c:292:12
> #10 0x55d5f8eed3f1 in qdev_device_add_from_qdict
> system/qdev-monitor.c:719:10
> #11 0x55d5f8eef7ff in qdev_device_add system/qdev-monitor.c:738:11
> #12 0x55d5f8f211f0 in device_init_func system/vl.c:1200:11
> #13 0x55d5fad0877d in qemu_opts_foreach util/qemu-option.c:1135:14
> #14 0x55d5f8f0df9c in qemu_create_cli_devices system/vl.c:2638:5
> #15 0x55d5f8f0db24 in qmp_x_exit_preconfig system/vl.c:2706:5
> #16 0x55d5f8f14dc0 in qemu_init system/vl.c:3737:9
> ...
> SUMMARY: AddressSanitizer: heap-buffer-overflow hw/sd/sdhci.c:564:39
> in sdhci_write_dataport
>
> Cc: qemu-sta...@nongnu.org
> Fixes: d7dfca0807 ("hw/sdhci: introduce standard SD host controller")
> Buglink: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=58813
> Reported-by: Alexander Bulekov <alx...@bu.edu>
> Reported-by: Chuhong Yuan <hsleste...@gmail.com>
> Signed-off-by: Philippe Mathieu-Daudé <phi...@linaro.org>
> ---
> hw/sd/sdhci.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c
> index c5e0bc018b..2dd88fa139 100644
> --- a/hw/sd/sdhci.c
> +++ b/hw/sd/sdhci.c
> @@ -552,7 +552,7 @@ static void sdhci_write_block_to_card(SDHCIState *s)
> * register */
> static void sdhci_write_dataport(SDHCIState *s, uint32_t value, unsigned
> size)
> {
> - unsigned i;
> + unsigned i, available;
>
> /* Check that there is free space left in a buffer */
> if (!(s->prnsts & SDHC_SPACE_AVAILABLE)) {
> @@ -560,6 +560,14 @@ static void sdhci_write_dataport(SDHCIState *s, uint32_t
> value, unsigned size)
> return;
> }
>
> + available = s->buf_maxsz - s->data_count;
> + if (size > available) {
> + qemu_log_mask(LOG_GUEST_ERROR, "SDHC buffer data full (size:
> %"PRIu32")"
> + " discarding %u byte%s\n",
> + s->buf_maxsz, size - available,
> + size - available > 1 ? "s" : "");
> + size = available; /* Excess data of the last write is ignored. */
> + }
> for (i = 0; i < size; i++) {
> s->fifo_buffer[s->data_count] = value & 0xFF;
> s->data_count++;
> --
> 2.41.0
>
Thank you Philippe. This was assigned CVE-2024-3447.
--
Mauro Matteo Cascella
Red Hat Product Security
PGP-Key ID: BB3410B0
