diff --git a/MAINTAINERS b/MAINTAINERS
index 3026b979b7..b4799a4329 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1823,7 +1823,8 @@ F: include/hw/sd/sd*
 F: hw/sd/core.c
 F: hw/sd/sd*
 F: hw/sd/ssi-sd.c
-F: tests/qtest/sd*
+F: tests/qtest/fuzz-sdcard-test.c
+F: tests/qtest/sdhci-test.c
 
 USB
 M: Gerd Hoffmann <kraxel@redhat.com>
diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 52f9769f60..1f964e022b 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -1380,6 +1380,11 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
 
         switch (sd->state) {
         case sd_transfer_state:
+            if (!address_in_range(sd, "SEND_WRITE_PROT",
+                                  req.arg, sd->blk_len)) {
+                return sd_r1;
+            }
+
             sd->state = sd_sendingdata_state;
             *(uint32_t *) sd->data = sd_wpbits(sd, req.arg);
             sd->data_start = addr;
diff --git a/tests/qtest/fuzz-sdcard-test.c b/tests/qtest/fuzz-sdcard-test.c
new file mode 100644
index 0000000000..96602eac7e
--- /dev/null
+++ b/tests/qtest/fuzz-sdcard-test.c
@@ -0,0 +1,66 @@
+/*
+ * QTest fuzzer-generated testcase for sdcard device
+ *
+ * Copyright (c) 2021 Philippe Mathieu-Daudé <f4bug@amsat.org>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "libqos/libqtest.h"
+
+/*
+ * https://gitlab.com/qemu-project/qemu/-/issues/450
+ * Used to trigger:
+ *  Assertion `wpnum < sd->wpgrps_size' failed.
+ */
+static void oss_fuzz_29225(void)
+{
+    QTestState *s;
+
+    s = qtest_init(" -display none -m 512m -nodefaults -nographic"
+                   " -device sdhci-pci,sd-spec-version=3"
+                   " -device sd-card,drive=d0"
+                   " -drive if=none,index=0,file=null-co://,format=raw,id=d0");
+
+    qtest_outl(s, 0xcf8, 0x80001010);
+    qtest_outl(s, 0xcfc, 0xd0690);
+    qtest_outl(s, 0xcf8, 0x80001003);
+    qtest_outl(s, 0xcf8, 0x80001013);
+    qtest_outl(s, 0xcfc, 0xffffffff);
+    qtest_outl(s, 0xcf8, 0x80001003);
+    qtest_outl(s, 0xcfc, 0x3effe00);
+
+    qtest_bufwrite(s, 0xff0d062c, "\xff", 0x1);
+    qtest_bufwrite(s, 0xff0d060f, "\xb7", 0x1);
+    qtest_bufwrite(s, 0xff0d060a, "\xc9", 0x1);
+    qtest_bufwrite(s, 0xff0d060f, "\x29", 0x1);
+    qtest_bufwrite(s, 0xff0d060f, "\xc2", 0x1);
+    qtest_bufwrite(s, 0xff0d0628, "\xf7", 0x1);
+    qtest_bufwrite(s, 0x0, "\xe3", 0x1);
+    qtest_bufwrite(s, 0x7, "\x13", 0x1);
+    qtest_bufwrite(s, 0x8, "\xe3", 0x1);
+    qtest_bufwrite(s, 0xf, "\xe3", 0x1);
+    qtest_bufwrite(s, 0xff0d060f, "\x03", 0x1);
+    qtest_bufwrite(s, 0xff0d0605, "\x01", 0x1);
+    qtest_bufwrite(s, 0xff0d060b, "\xff", 0x1);
+    qtest_bufwrite(s, 0xff0d060c, "\xff", 0x1);
+    qtest_bufwrite(s, 0xff0d060e, "\xff", 0x1);
+    qtest_bufwrite(s, 0xff0d060f, "\x06", 0x1);
+    qtest_bufwrite(s, 0xff0d060f, "\x9e", 0x1);
+
+    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/sdcard/oss_fuzz_29225", oss_fuzz_29225);
+   }
+
+   return g_test_run();
+}
diff --git a/tests/qtest/meson.build b/tests/qtest/meson.build
index ee7347b727..e22a0792c5 100644
--- a/tests/qtest/meson.build
+++ b/tests/qtest/meson.build
@@ -21,6 +21,7 @@ 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'] : []) + \
+  (config_all_devices.has_key('CONFIG_SDHCI_PCI') ? ['fuzz-sdcard-test'] : []) + \
   [
   'cdrom-test',
   'device-introspect-test',