Commit message: hw/sd: sdhci: Don't transfer any data when command time out

At the end of sdhci_send_command(), it starts a data transfer if the
command register indicates data is associated. But the data transfer
should only be initiated when the command execution has succeeded.

With this fix, the following reproducer:

outl 0xcf8 0x80001810
outl 0xcfc 0xe1068000
outl 0xcf8 0x80001804
outw 0xcfc 0x7
write 0xe106802c 0x1 0x0f
write 0xe1068004 0xc 0x2801d10101fffffbff28a384
write 0xe106800c 0x1f 0x9dacbbcad9e8f7061524334251606f7e8d9cabbac9d8e7f60514233241505f
write 0xe1068003 0x28 0x80d000251480d000252280d000253080d000253e80d000254c80d000255a80d000256880d0002576
write 0xe1068003 0x1 0xfe

cannot be reproduced with the following QEMU command line:

$ qemu-system-x86_64 -nographic -M pc-q35-5.0 \
      -device sdhci-pci,sd-spec-version=3 \
      -drive if=sd,index=0,file=null-co://,format=raw,id=mydrive \
      -device sd-card,drive=mydrive \
      -monitor none -serial none -qtest stdio

Cc: qemu-stable@nongnu.org
Fixes: CVE-2020-17380
Fixes: CVE-2020-25085
Fixes: CVE-2021-3409
Fixes: d7dfca0807a0 ("hw/sdhci: introduce standard SD host controller")
Reported-by: Alexander Bulekov <alxndr@bu.edu>
Reported-by: Cornelius Aschermann (Ruhr-Universität Bochum)
Reported-by: Sergej Schumilo (Ruhr-Universität Bochum)
Reported-by: Simon Wörner (Ruhr-Universität Bochum)
Buglink: https://bugs.launchpad.net/qemu/+bug/1892960
Buglink: https://bugs.launchpad.net/qemu/+bug/1909418
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1928146
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Tested-by: Alexander Bulekov <alxndr@bu.edu>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Message-Id: <20210303122639.20004-2-bmeng.cn@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
CVE: CVE-2021-3409
CWE: CWE-119
Vulnerability description: The patch for CVE-2020-17380/CVE-2020-25085 was found to be ineffective, thus making QEMU vulnerable to the out-of-bounds read/write access issues previously found in the SDHCI controller emulation code. This flaw allows a malicious privileged guest to crash the QEMU process on the host, resulting in a denial of service or potential code execution. QEMU up to (including) 5.2.0 is affected by this.

Project: qemu
File: sdhci.c

static void sdhci_send_command(SDHCIState *s)
{
    SDRequest request;
    uint8_t response[16];
    int rlen;

    s->errintsts = 0;
    s->acmd12errsts = 0;
    request.cmd = s->cmdreg >> 8;
    request.arg = s->argument;

    trace_sdhci_send_command(request.cmd, request.arg);
    rlen = sdbus_do_command(&s->sdbus, &request, response);

    if (s->cmdreg & SDHC_CMD_RESPONSE) {
        if (rlen == 4) {
            s->rspreg[0] = ldl_be_p(response);
            s->rspreg[1] = s->rspreg[2] = s->rspreg[3] = 0;
            trace_sdhci_response4(s->rspreg[0]);
        } else if (rlen == 16) {
            s->rspreg[0] = ldl_be_p(&response[11]);
            s->rspreg[1] = ldl_be_p(&response[7]);
            s->rspreg[2] = ldl_be_p(&response[3]);
            s->rspreg[3] = (response[0] << 16) | (response[1] << 8) |
                            response[2];
            trace_sdhci_response16(s->rspreg[3], s->rspreg[2],
                                   s->rspreg[1], s->rspreg[0]);
        } else {
            trace_sdhci_error("timeout waiting for command response");
            if (s->errintstsen & SDHC_EISEN_CMDTIMEOUT) {
                s->errintsts |= SDHC_EIS_CMDTIMEOUT;
                s->norintsts |= SDHC_NIS_ERR;
            }
        }

        if (!(s->quirks & SDHCI_QUIRK_NO_BUSY_IRQ) &&
            (s->norintstsen & SDHC_NISEN_TRSCMP) &&
            (s->cmdreg & SDHC_CMD_RESPONSE) == SDHC_CMD_RSP_WITH_BUSY) {
            s->norintsts |= SDHC_NIS_TRSCMP;
        }
    }

    if (s->norintstsen & SDHC_NISEN_CMDCMP) {
        s->norintsts |= SDHC_NIS_CMDCMP;
    }

    sdhci_update_irq(s);

    if (s->blksize && (s->cmdreg & SDHC_CMD_DATA_PRESENT)) {
        s->data_count = 0;
        sdhci_data_transfer(s);
    }
}