qemu/tests/nvme-test.c
Paolo Bonzini 87ad860c62 nvme: fix out-of-bounds access to the CMB
Because the CMB BAR has a min_access_size of 2, if you read the last
byte it will try to memcpy *2* bytes from n->cmbuf, causing an off-by-one
error.  This is CVE-2018-16847.

Another way to fix this might be to register the CMB as a RAM memory
region, which would also be more efficient.  However, that might be a
change for big-endian machines; I didn't think this through and I don't
know how real hardware works.  Add a basic testcase for the CMB in case
somebody does this change later on.

Cc: Keith Busch <keith.busch@intel.com>
Cc: qemu-block@nongnu.org
Reported-by: Li Qiang <liq3ea@gmail.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
Tested-by: Li Qiang <liq3ea@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-11-22 16:43:52 +01:00

80 lines
2 KiB
C

/*
* QTest testcase for NVMe
*
* Copyright (c) 2014 SUSE LINUX Products GmbH
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "qemu/units.h"
#include "libqtest.h"
#include "libqos/libqos-pc.h"
static QOSState *qnvme_start(const char *extra_opts)
{
QOSState *qs;
const char *arch = qtest_get_arch();
const char *cmd = "-drive id=drv0,if=none,file=null-co://,format=raw "
"-device nvme,addr=0x4.0,serial=foo,drive=drv0 %s";
if (strcmp(arch, "i386") == 0 || strcmp(arch, "x86_64") == 0) {
qs = qtest_pc_boot(cmd, extra_opts ? : "");
global_qtest = qs->qts;
return qs;
}
g_printerr("nvme tests are only available on x86\n");
exit(EXIT_FAILURE);
}
static void qnvme_stop(QOSState *qs)
{
qtest_shutdown(qs);
}
static void nop(void)
{
QOSState *qs;
qs = qnvme_start(NULL);
qnvme_stop(qs);
}
static void nvmetest_cmb_test(void)
{
const int cmb_bar_size = 2 * MiB;
QOSState *qs;
QPCIDevice *pdev;
QPCIBar bar;
qs = qnvme_start("-global nvme.cmb_size_mb=2");
pdev = qpci_device_find(qs->pcibus, QPCI_DEVFN(4,0));
g_assert(pdev != NULL);
qpci_device_enable(pdev);
bar = qpci_iomap(pdev, 2, NULL);
qpci_io_writel(pdev, bar, 0, 0xccbbaa99);
g_assert_cmpint(qpci_io_readb(pdev, bar, 0), ==, 0x99);
g_assert_cmpint(qpci_io_readw(pdev, bar, 0), ==, 0xaa99);
/* Test partially out-of-bounds accesses. */
qpci_io_writel(pdev, bar, cmb_bar_size - 1, 0x44332211);
g_assert_cmpint(qpci_io_readb(pdev, bar, cmb_bar_size - 1), ==, 0x11);
g_assert_cmpint(qpci_io_readw(pdev, bar, cmb_bar_size - 1), !=, 0x2211);
g_assert_cmpint(qpci_io_readl(pdev, bar, cmb_bar_size - 1), !=, 0x44332211);
g_free(pdev);
qnvme_stop(qs);
}
int main(int argc, char **argv)
{
g_test_init(&argc, &argv, NULL);
qtest_add_func("/nvme/nop", nop);
qtest_add_func("/nvme/cmb_test", nvmetest_cmb_test);
return g_test_run();
}