[v4,18/20] fuzz: add i440fx fuzz targets

Commit Message

Alexander Bulekov Oct. 30, 2019, 2:50 p.m. UTC

From: Alexander Oleinik <[e-mail]>

These three targets should simply fuzz reads/writes to a couple ioports,
but they mostly serve as examples of different ways to write targets.
They demonstrate using qtest and qos for fuzzing, as well as using
rebooting and forking to reset state, or not resetting it at all.

Signed-off-by: Alexander Oleinik <[e-mail]>
---
 tests/fuzz/Makefile.include |   3 +
 tests/fuzz/i440fx_fuzz.c    | 176 ++++++++++++++++++++++++++++++++++++
 2 files changed, 179 insertions(+)
 create mode 100644 tests/fuzz/i440fx_fuzz.c

Comments

Stefan Hajnoczi Nov. 7, 2019, 1:26 p.m. UTC | #1

On Wed, Oct 30, 2019 at 02:50:03PM +0000, Oleinik, Alexander wrote:
> +static void i440fx_fuzz_qos_fork(QTestState *s,
> +        const unsigned char *Data, size_t Size) {
> +    if (fork() == 0) {
> +        i440fx_fuzz_qos(s, Data, Size);
> +        _Exit(0);
> +    } else {
> +        wait(NULL);
> +    }
> +}
> +
> +static const char *i440fx_qtest_argv = "qemu_system_i386 -machine accel=qtest"

Binaries are named qemu-system-TARGET.  I guess nothing looks at argv[0]
but it should use hyphens instead of underscores.

> +                                       "-m 0 -display none";
> +static char *i440fx_argv(FuzzTarget *t)
> +{
> +    return (char *)i440fx_qtest_argv;

.get_init_cmdline() should probably return const char *.

Otherwise:

Reviewed-by: Stefan Hajnoczi <[e-mail]>

Patch

diff --git a/tests/fuzz/Makefile.include b/tests/fuzz/Makefile.include
index 687dacce04..37d6821bee 100644
--- a/tests/fuzz/Makefile.include
+++ b/tests/fuzz/Makefile.include
@@ -3,5 +3,8 @@  fuzz-obj-y = $(libqos-obj-y)
 fuzz-obj-y += tests/libqtest.o
 fuzz-obj-y += tests/fuzz/fuzz.o
 fuzz-obj-y += tests/fuzz/fork_fuzz.o
+fuzz-obj-y += tests/fuzz/qos_fuzz.o
+
+fuzz-obj-y += tests/fuzz/i440fx_fuzz.o
 
 FUZZ_LDFLAGS += -Xlinker -T$(SRC_PATH)/tests/fuzz/fork_fuzz.ld
diff --git a/tests/fuzz/i440fx_fuzz.c b/tests/fuzz/i440fx_fuzz.c
new file mode 100644
index 0000000000..7304465b42
--- /dev/null
+++ b/tests/fuzz/i440fx_fuzz.c
@@ -0,0 +1,176 @@ 
+/*
+ * I440FX Fuzzing Target
+ *
+ * Copyright Red Hat Inc., 2019
+ *
+ * Authors:
+ *  Alexander Bulekov   <[e-mail]>
+ *
+ * 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 "fuzz.h"
+#include "tests/libqtest.h"
+#include "fuzz/qos_fuzz.h"
+#include "fuzz/fork_fuzz.h"
+#include "qemu/main-loop.h"
+#include "tests/libqos/pci.h"
+#include "tests/libqos/pci-pc.h"
+
+
+#define I440FX_PCI_HOST_BRIDGE_CFG 0xcf8
+#define I440FX_PCI_HOST_BRIDGE_DATA 0xcfc
+
+enum action_id {
+    WRITEB,
+    WRITEW,
+    WRITEL,
+    READB,
+    READW,
+    READL,
+    ACTION_MAX
+};
+
+static void i440fx_fuzz_qtest(QTestState *s,
+        const unsigned char *Data, size_t Size) {
+    typedef struct QTestFuzzAction {
+        uint32_t value;
+        uint8_t id;
+        uint8_t addr;
+    } QTestFuzzAction;
+    QTestFuzzAction a;
+
+    while (Size >= sizeof(a)) {
+        memcpy(&a, Data, sizeof(a));
+        uint16_t addr = a.addr % 2 ? I440FX_PCI_HOST_BRIDGE_CFG :
+                                      I440FX_PCI_HOST_BRIDGE_DATA;
+        switch (a.id % ACTION_MAX) {
+        case WRITEB:
+            qtest_outb(s, addr, (uint8_t)a.value);
+            break;
+        case WRITEW:
+            qtest_outw(s, addr, (uint16_t)a.value);
+            break;
+        case WRITEL:
+            qtest_outl(s, addr, (uint32_t)a.value);
+            break;
+        case READB:
+            qtest_inb(s, addr);
+            break;
+        case READW:
+            qtest_inw(s, addr);
+            break;
+        case READL:
+            qtest_inl(s, addr);
+            break;
+        }
+        Size -= sizeof(a);
+        Data += sizeof(a);
+    }
+    flush_events(s);
+}
+
+static void i440fx_fuzz_qos(QTestState *s,
+        const unsigned char *Data, size_t Size) {
+
+    typedef struct QOSFuzzAction {
+        uint32_t value;
+        int devfn;
+        uint8_t offset;
+        uint8_t id;
+    } QOSFuzzAction;
+
+    static QPCIBus *bus;
+    if (!bus) {
+        bus = qpci_new_pc(s, fuzz_qos_alloc);
+    }
+
+    QOSFuzzAction a;
+    while (Size >= sizeof(a)) {
+        memcpy(&a, Data, sizeof(a));
+        switch (a.id % ACTION_MAX) {
+        case WRITEB:
+            bus->config_writeb(bus, a.devfn, a.offset, (uint8_t)a.value);
+            break;
+        case WRITEW:
+            bus->config_writew(bus, a.devfn, a.offset, (uint16_t)a.value);
+            break;
+        case WRITEL:
+            bus->config_writel(bus, a.devfn, a.offset, (uint32_t)a.value);
+            break;
+        case READB:
+            bus->config_readb(bus, a.devfn, a.offset);
+            break;
+        case READW:
+            bus->config_readw(bus, a.devfn, a.offset);
+            break;
+        case READL:
+            bus->config_readl(bus, a.devfn, a.offset);
+            break;
+        }
+        Size -= sizeof(a);
+        Data += sizeof(a);
+    }
+    flush_events(s);
+}
+
+static void i440fx_fuzz_qos_fork(QTestState *s,
+        const unsigned char *Data, size_t Size) {
+    if (fork() == 0) {
+        i440fx_fuzz_qos(s, Data, Size);
+        _Exit(0);
+    } else {
+        wait(NULL);
+    }
+}
+
+static const char *i440fx_qtest_argv = "qemu_system_i386 -machine accel=qtest"
+                                       "-m 0 -display none";
+static char *i440fx_argv(FuzzTarget *t)
+{
+    return (char *)i440fx_qtest_argv;
+}
+
+static void fork_init(void)
+{
+    counter_shm_init();
+}
+
+static void register_pci_fuzz_targets(void)
+{
+    /* Uses simple qtest commands and reboots to reset state */
+    fuzz_add_target(&(FuzzTarget){
+                .name = "i440fx-qtest-reboot-fuzz",
+                .description = "Fuzz the i440fx using raw qtest commands and"
+                               "rebooting after each run",
+                .get_init_cmdline = i440fx_argv,
+                .fuzz = i440fx_fuzz_qtest});
+
+    /* Uses libqos and forks to prevent state leakage */
+    fuzz_add_qos_target(&(FuzzTarget){
+                .name = "i440fx-qos-fork-fuzz",
+                .description = "Fuzz the i440fx using raw qtest commands and"
+                               "rebooting after each run",
+                .pre_vm_init = &fork_init,
+                .fuzz = i440fx_fuzz_qos_fork,},
+                "i440FX-pcihost",
+                &(QOSGraphTestOptions){}
+                );
+
+    /* Uses libqos. Doesn't do anything to reset state. Note that if we were to
+     reboot after each run, we would also have to redo the qos-related
+     initialization (qos_init_path) */
+    fuzz_add_qos_target(&(FuzzTarget){
+                .name = "i440fx-qos-noreset-fuzz",
+                .description = "Fuzz the i440fx using raw qtest commands and"
+                               "rebooting after each run",
+                .fuzz = i440fx_fuzz_qos,},
+                "i440FX-pcihost",
+                &(QOSGraphTestOptions){}
+                );
+}
+
+fuzz_target_init(register_pci_fuzz_targets);