| Message ID | 20200129053357.27454-20-alxndr@bu.edu |
|---|---|
| State | New |
| Headers | show |
| Series | [v8,01/21] softmmu: split off vl.c:main() into main.c | expand |
On Wed, Jan 29, 2020 at 05:34:27AM +0000, Bulekov, Alexander wrote: > The virtio-net fuzz target feeds inputs to all three virtio-net > virtqueues, and uses forking to avoid leaking state between fuzz runs. > > Signed-off-by: Alexander Bulekov <alxndr@bu.edu> > --- > tests/qtest/fuzz/Makefile.include | 1 + > tests/qtest/fuzz/virtio_net_fuzz.c | 195 +++++++++++++++++++++++++++++ > 2 files changed, 196 insertions(+) > create mode 100644 tests/qtest/fuzz/virtio_net_fuzz.c Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
On Wed, Jan 29, 2020 at 05:34:27AM +0000, Bulekov, Alexander wrote: >The virtio-net fuzz target feeds inputs to all three virtio-net >virtqueues, and uses forking to avoid leaking state between fuzz runs. > >Signed-off-by: Alexander Bulekov <alxndr@bu.edu> >--- > tests/qtest/fuzz/Makefile.include | 1 + > tests/qtest/fuzz/virtio_net_fuzz.c | 195 +++++++++++++++++++++++++++++ > 2 files changed, 196 insertions(+) > create mode 100644 tests/qtest/fuzz/virtio_net_fuzz.c > >diff --git a/tests/qtest/fuzz/Makefile.include b/tests/qtest/fuzz/Makefile.include >index 38b8cdd9f1..77385777ef 100644 >--- a/tests/qtest/fuzz/Makefile.include >+++ b/tests/qtest/fuzz/Makefile.include >@@ -8,6 +8,7 @@ fuzz-obj-y += tests/qtest/fuzz/qos_fuzz.o > > # Targets > fuzz-obj-y += tests/qtest/fuzz/i440fx_fuzz.o >+fuzz-obj-y += tests/qtest/fuzz/virtio_net_fuzz.o > > FUZZ_CFLAGS += -I$(SRC_PATH)/tests -I$(SRC_PATH)/tests/qtest > >diff --git a/tests/qtest/fuzz/virtio_net_fuzz.c b/tests/qtest/fuzz/virtio_net_fuzz.c >new file mode 100644 >index 0000000000..e4e3e50865 >--- /dev/null >+++ b/tests/qtest/fuzz/virtio_net_fuzz.c >@@ -0,0 +1,195 @@ >+/* >+ * virtio-net Fuzzing Target >+ * >+ * Copyright Red Hat Inc., 2019 >+ * >+ * Authors: >+ * Alexander Bulekov <alxndr@bu.edu> >+ * >+ * 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 "standard-headers/linux/virtio_config.h" >+#include "tests/qtest/libqtest.h" >+#include "tests/qtest/libqos/virtio-net.h" >+#include "fuzz.h" >+#include "fork_fuzz.h" >+#include "qos_fuzz.h" >+ >+ >+#define QVIRTIO_NET_TIMEOUT_US (30 * 1000 * 1000) >+#define QVIRTIO_RX_VQ 0 >+#define QVIRTIO_TX_VQ 1 >+#define QVIRTIO_CTRL_VQ 2 >+ >+static int sockfds[2]; >+static bool sockfds_initialized; >+ >+static void virtio_net_fuzz_multi(QTestState *s, >+ const unsigned char *Data, size_t Size, bool check_used) >+{ >+ typedef struct vq_action { >+ uint8_t queue; >+ uint8_t length; >+ uint8_t write; >+ uint8_t next; >+ uint8_t rx; >+ } vq_action; >+ >+ uint32_t free_head = 0; >+ >+ QGuestAllocator *t_alloc = fuzz_qos_alloc; >+ >+ QVirtioNet *net_if = fuzz_qos_obj; >+ QVirtioDevice *dev = net_if->vdev; >+ QVirtQueue *q; >+ vq_action vqa; >+ while (Size >= sizeof(vqa)) { >+ memcpy(&vqa, Data, sizeof(vqa)); >+ Data += sizeof(vqa); >+ Size -= sizeof(vqa); >+ >+ q = net_if->queues[vqa.queue % 3]; >+ >+ vqa.length = vqa.length >= Size ? Size : vqa.length; >+ >+ /* >+ * Only attempt to write incoming packets, when using the socket >+ * backend. Otherwise, always place the input on a virtqueue. >+ */ >+ if (vqa.rx && sockfds_initialized) { >+ write(sockfds[0], Data, vqa.length); >+ } else { >+ vqa.rx = 0; >+ uint64_t req_addr = guest_alloc(t_alloc, vqa.length); >+ /* >+ * If checking used ring, ensure that the fuzzer doesn't trigger >+ * trivial asserion failure on zero-zied buffer >+ */ >+ qtest_memwrite(s, req_addr, Data, vqa.length); >+ >+ >+ free_head = qvirtqueue_add(s, q, req_addr, vqa.length, >+ vqa.write, vqa.next); >+ qvirtqueue_add(s, q, req_addr, vqa.length, vqa.write , vqa.next); >+ qvirtqueue_kick(s, dev, q, free_head); >+ } >+ >+ /* >+ * normally, we could just use qvirtio_wait_used_elem, but since we >+ * must manually run the main-loop for all the bhs to run, we use >+ * this hack with flush_events(), to run the main_loop >+ */ >+ gint64 start_time = g_get_monotonic_time(); NIT: It's a little unclear using a for(;;) when in reality, for most use-cases, other than virtio_net_fork_fuzz_check_used() it will never really loop around. Maybe it would be clearer if the parts that never repeat were outside the loop? e.g. /* Run the main loop */ qtest_clock_step(s, 100); flush_events(s); /* Poll the used vring only if we added to the TX or CTRL vq */ while (check_used && !vqa.rx && q != net_if->queues[QVIRTIO_RX_VQ]) { uint32_t got_desc_idx; /* Input led to a virtio_error */ if (dev->bus->get_status(dev) & VIRTIO_CONFIG_S_NEEDS_RESET) { break; } if (dev->bus->get_queue_isr_status(dev, q) && qvirtqueue_get_buf(s, q, &got_desc_idx, NULL)) { g_assert_cmpint(got_desc_idx, ==, free_head); break; } g_assert(g_get_monotonic_time() - start_time <= QVIRTIO_NET_TIMEOUT_US); /* Run the main loop */ qtest_clock_step(s, 100); flush_events(s); } Unless I'm reading it incorrectly that should do the same thing. Thanks, Darren. >+ for (;;) { >+ /* Run the main loop */ >+ qtest_clock_step(s, 100); >+ flush_events(s); >+ /* Poll the used vring only if we added to the TX or CTRL vq */ >+ if (check_used && !vqa.rx && q != net_if->queues[QVIRTIO_RX_VQ]) { >+ uint32_t got_desc_idx; >+ /* Input led to a virtio_error */ >+ if (dev->bus->get_status(dev) & VIRTIO_CONFIG_S_NEEDS_RESET) { >+ break; >+ } >+ if (dev->bus->get_queue_isr_status(dev, q) && >+ qvirtqueue_get_buf(s, q, &got_desc_idx, NULL)) { >+ g_assert_cmpint(got_desc_idx, ==, free_head); >+ break; >+ } >+ g_assert(g_get_monotonic_time() - start_time >+ <= QVIRTIO_NET_TIMEOUT_US); >+ } else { >+ break; >+ } >+ } >+ Data += vqa.length; >+ Size -= vqa.length; >+ } >+} >+ >+static void virtio_net_fork_fuzz(QTestState *s, >+ const unsigned char *Data, size_t Size) >+{ >+ if (fork() == 0) { >+ virtio_net_fuzz_multi(s, Data, Size, false); >+ flush_events(s); >+ _Exit(0); >+ } else { >+ wait(NULL); >+ } >+} >+ >+static void virtio_net_fork_fuzz_check_used(QTestState *s, >+ const unsigned char *Data, size_t Size) >+{ >+ if (fork() == 0) { >+ virtio_net_fuzz_multi(s, Data, Size, true); >+ flush_events(s); >+ _Exit(0); >+ } else { >+ wait(NULL); >+ } >+} >+ >+static void virtio_net_pre_fuzz(QTestState *s) >+{ >+ qos_init_path(s); >+ counter_shm_init(); >+} >+ >+static void *virtio_net_test_setup_socket(GString *cmd_line, void *arg) >+{ >+ int ret = socketpair(PF_UNIX, SOCK_STREAM, 0, sockfds); >+ g_assert_cmpint(ret, !=, -1); >+ fcntl(sockfds[0], F_SETFL, O_NONBLOCK); >+ sockfds_initialized = true; >+ g_string_append_printf(cmd_line, " -netdev socket,fd=%d,id=hs0 ", >+ sockfds[1]); >+ return arg; >+} >+ >+static void *virtio_net_test_setup_user(GString *cmd_line, void *arg) >+{ >+ g_string_append_printf(cmd_line, " -netdev user,id=hs0 "); >+ return arg; >+} >+ >+static void register_virtio_net_fuzz_targets(void) >+{ >+ fuzz_add_qos_target(&(FuzzTarget){ >+ .name = "virtio-net-socket", >+ .description = "Fuzz the virtio-net virtual queues. Fuzz incoming " >+ "traffic using the socket backend", >+ .pre_fuzz = &virtio_net_pre_fuzz, >+ .fuzz = virtio_net_fork_fuzz,}, >+ "virtio-net", >+ &(QOSGraphTestOptions){.before = virtio_net_test_setup_socket} >+ ); >+ >+ fuzz_add_qos_target(&(FuzzTarget){ >+ .name = "virtio-net-socket-check-used", >+ .description = "Fuzz the virtio-net virtual queues. Wait for the " >+ "descriptors to be used. Timeout may indicate improperly handled " >+ "input", >+ .pre_fuzz = &virtio_net_pre_fuzz, >+ .fuzz = virtio_net_fork_fuzz_check_used,}, >+ "virtio-net", >+ &(QOSGraphTestOptions){.before = virtio_net_test_setup_socket} >+ ); >+ fuzz_add_qos_target(&(FuzzTarget){ >+ .name = "virtio-net-slirp", >+ .description = "Fuzz the virtio-net virtual queues with the slirp " >+ " backend. Warning: May result in network traffic emitted from the " >+ " process. Run in an isolated network environment.", NIT: s/" /"/ (fix double-spaces) >+ .pre_fuzz = &virtio_net_pre_fuzz, >+ .fuzz = virtio_net_fork_fuzz,}, >+ "virtio-net", >+ &(QOSGraphTestOptions){.before = virtio_net_test_setup_user} >+ ); >+} >+ >+fuzz_target_init(register_virtio_net_fuzz_targets); >-- >2.23.0 > >
On 200205 1357, Darren Kenny wrote: > On Wed, Jan 29, 2020 at 05:34:27AM +0000, Bulekov, Alexander wrote: > > The virtio-net fuzz target feeds inputs to all three virtio-net > > virtqueues, and uses forking to avoid leaking state between fuzz runs. > > > > Signed-off-by: Alexander Bulekov <alxndr@bu.edu> > > --- > > tests/qtest/fuzz/Makefile.include | 1 + > > tests/qtest/fuzz/virtio_net_fuzz.c | 195 +++++++++++++++++++++++++++++ > > 2 files changed, 196 insertions(+) > > create mode 100644 tests/qtest/fuzz/virtio_net_fuzz.c > > > > diff --git a/tests/qtest/fuzz/Makefile.include b/tests/qtest/fuzz/Makefile.include > > index 38b8cdd9f1..77385777ef 100644 > > --- a/tests/qtest/fuzz/Makefile.include > > +++ b/tests/qtest/fuzz/Makefile.include > > @@ -8,6 +8,7 @@ fuzz-obj-y += tests/qtest/fuzz/qos_fuzz.o > > > > # Targets > > fuzz-obj-y += tests/qtest/fuzz/i440fx_fuzz.o > > +fuzz-obj-y += tests/qtest/fuzz/virtio_net_fuzz.o > > > > FUZZ_CFLAGS += -I$(SRC_PATH)/tests -I$(SRC_PATH)/tests/qtest > > > > diff --git a/tests/qtest/fuzz/virtio_net_fuzz.c b/tests/qtest/fuzz/virtio_net_fuzz.c > > new file mode 100644 > > index 0000000000..e4e3e50865 > > --- /dev/null > > +++ b/tests/qtest/fuzz/virtio_net_fuzz.c > > @@ -0,0 +1,195 @@ > > +/* > > + * virtio-net Fuzzing Target > > + * > > + * Copyright Red Hat Inc., 2019 > > + * > > + * Authors: > > + * Alexander Bulekov <alxndr@bu.edu> > > + * > > + * 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 "standard-headers/linux/virtio_config.h" > > +#include "tests/qtest/libqtest.h" > > +#include "tests/qtest/libqos/virtio-net.h" > > +#include "fuzz.h" > > +#include "fork_fuzz.h" > > +#include "qos_fuzz.h" > > + > > + > > +#define QVIRTIO_NET_TIMEOUT_US (30 * 1000 * 1000) > > +#define QVIRTIO_RX_VQ 0 > > +#define QVIRTIO_TX_VQ 1 > > +#define QVIRTIO_CTRL_VQ 2 > > + > > +static int sockfds[2]; > > +static bool sockfds_initialized; > > + > > +static void virtio_net_fuzz_multi(QTestState *s, > > + const unsigned char *Data, size_t Size, bool check_used) > > +{ > > + typedef struct vq_action { > > + uint8_t queue; > > + uint8_t length; > > + uint8_t write; > > + uint8_t next; > > + uint8_t rx; > > + } vq_action; > > + > > + uint32_t free_head = 0; > > + > > + QGuestAllocator *t_alloc = fuzz_qos_alloc; > > + > > + QVirtioNet *net_if = fuzz_qos_obj; > > + QVirtioDevice *dev = net_if->vdev; > > + QVirtQueue *q; > > + vq_action vqa; > > + while (Size >= sizeof(vqa)) { > > + memcpy(&vqa, Data, sizeof(vqa)); > > + Data += sizeof(vqa); > > + Size -= sizeof(vqa); > > + > > + q = net_if->queues[vqa.queue % 3]; > > + > > + vqa.length = vqa.length >= Size ? Size : vqa.length; > > + > > + /* > > + * Only attempt to write incoming packets, when using the socket > > + * backend. Otherwise, always place the input on a virtqueue. > > + */ > > + if (vqa.rx && sockfds_initialized) { > > + write(sockfds[0], Data, vqa.length); > > + } else { > > + vqa.rx = 0; > > + uint64_t req_addr = guest_alloc(t_alloc, vqa.length); > > + /* > > + * If checking used ring, ensure that the fuzzer doesn't trigger > > + * trivial asserion failure on zero-zied buffer > > + */ > > + qtest_memwrite(s, req_addr, Data, vqa.length); > > + > > + > > + free_head = qvirtqueue_add(s, q, req_addr, vqa.length, > > + vqa.write, vqa.next); > > + qvirtqueue_add(s, q, req_addr, vqa.length, vqa.write , vqa.next); > > + qvirtqueue_kick(s, dev, q, free_head); > > + } > > + > > + /* > > + * normally, we could just use qvirtio_wait_used_elem, but since we > > + * must manually run the main-loop for all the bhs to run, we use > > + * this hack with flush_events(), to run the main_loop > > + */ > > + gint64 start_time = g_get_monotonic_time(); > > NIT: It's a little unclear using a for(;;) when in reality, for most > use-cases, other than virtio_net_fork_fuzz_check_used() it will > never really loop around. > > Maybe it would be clearer if the parts that never repeat were > outside the loop? e.g. > > /* Run the main loop */ > qtest_clock_step(s, 100); > flush_events(s); > > /* Poll the used vring only if we added to the TX or CTRL vq */ > while (check_used && !vqa.rx && q != net_if->queues[QVIRTIO_RX_VQ]) { > uint32_t got_desc_idx; > /* Input led to a virtio_error */ > if (dev->bus->get_status(dev) & VIRTIO_CONFIG_S_NEEDS_RESET) { > break; > } > if (dev->bus->get_queue_isr_status(dev, q) && > qvirtqueue_get_buf(s, q, &got_desc_idx, NULL)) { > g_assert_cmpint(got_desc_idx, ==, free_head); > break; > } > g_assert(g_get_monotonic_time() - start_time > <= QVIRTIO_NET_TIMEOUT_US); > > /* Run the main loop */ > qtest_clock_step(s, 100); > flush_events(s); > } > > Unless I'm reading it incorrectly that should do the same thing. This is more readable and should do the same thing. I'll change it. -Alex > Thanks, > > Darren. > > > + for (;;) { > > + /* Run the main loop */ > > + qtest_clock_step(s, 100); > > + flush_events(s); > > + /* Poll the used vring only if we added to the TX or CTRL vq */ > > + if (check_used && !vqa.rx && q != net_if->queues[QVIRTIO_RX_VQ]) { > > + uint32_t got_desc_idx; > > + /* Input led to a virtio_error */ > > + if (dev->bus->get_status(dev) & VIRTIO_CONFIG_S_NEEDS_RESET) { > > + break; > > + } > > + if (dev->bus->get_queue_isr_status(dev, q) && > > + qvirtqueue_get_buf(s, q, &got_desc_idx, NULL)) { > > + g_assert_cmpint(got_desc_idx, ==, free_head); > > + break; > > + } > > + g_assert(g_get_monotonic_time() - start_time > > + <= QVIRTIO_NET_TIMEOUT_US); > > + } else { > > + break; > > + } > > + } > > + Data += vqa.length; > > + Size -= vqa.length; > > + } > > +} > > + > > +static void virtio_net_fork_fuzz(QTestState *s, > > + const unsigned char *Data, size_t Size) > > +{ > > + if (fork() == 0) { > > + virtio_net_fuzz_multi(s, Data, Size, false); > > + flush_events(s); > > + _Exit(0); > > + } else { > > + wait(NULL); > > + } > > +} > > + > > +static void virtio_net_fork_fuzz_check_used(QTestState *s, > > + const unsigned char *Data, size_t Size) > > +{ > > + if (fork() == 0) { > > + virtio_net_fuzz_multi(s, Data, Size, true); > > + flush_events(s); > > + _Exit(0); > > + } else { > > + wait(NULL); > > + } > > +} > > + > > +static void virtio_net_pre_fuzz(QTestState *s) > > +{ > > + qos_init_path(s); > > + counter_shm_init(); > > +} > > + > > +static void *virtio_net_test_setup_socket(GString *cmd_line, void *arg) > > +{ > > + int ret = socketpair(PF_UNIX, SOCK_STREAM, 0, sockfds); > > + g_assert_cmpint(ret, !=, -1); > > + fcntl(sockfds[0], F_SETFL, O_NONBLOCK); > > + sockfds_initialized = true; > > + g_string_append_printf(cmd_line, " -netdev socket,fd=%d,id=hs0 ", > > + sockfds[1]); > > + return arg; > > +} > > + > > +static void *virtio_net_test_setup_user(GString *cmd_line, void *arg) > > +{ > > + g_string_append_printf(cmd_line, " -netdev user,id=hs0 "); > > + return arg; > > +} > > + > > +static void register_virtio_net_fuzz_targets(void) > > +{ > > + fuzz_add_qos_target(&(FuzzTarget){ > > + .name = "virtio-net-socket", > > + .description = "Fuzz the virtio-net virtual queues. Fuzz incoming " > > + "traffic using the socket backend", > > + .pre_fuzz = &virtio_net_pre_fuzz, > > + .fuzz = virtio_net_fork_fuzz,}, > > + "virtio-net", > > + &(QOSGraphTestOptions){.before = virtio_net_test_setup_socket} > > + ); > > + > > + fuzz_add_qos_target(&(FuzzTarget){ > > + .name = "virtio-net-socket-check-used", > > + .description = "Fuzz the virtio-net virtual queues. Wait for the " > > + "descriptors to be used. Timeout may indicate improperly handled " > > + "input", > > + .pre_fuzz = &virtio_net_pre_fuzz, > > + .fuzz = virtio_net_fork_fuzz_check_used,}, > > + "virtio-net", > > + &(QOSGraphTestOptions){.before = virtio_net_test_setup_socket} > > + ); > > + fuzz_add_qos_target(&(FuzzTarget){ > > + .name = "virtio-net-slirp", > > + .description = "Fuzz the virtio-net virtual queues with the slirp " > > + " backend. Warning: May result in network traffic emitted from the " > > + " process. Run in an isolated network environment.", > > NIT: s/" /"/ (fix double-spaces) > > > + .pre_fuzz = &virtio_net_pre_fuzz, > > + .fuzz = virtio_net_fork_fuzz,}, > > + "virtio-net", > > + &(QOSGraphTestOptions){.before = virtio_net_test_setup_user} > > + ); > > +} > > + > > +fuzz_target_init(register_virtio_net_fuzz_targets); > > -- > > 2.23.0 > > > >
diff --git a/tests/qtest/fuzz/Makefile.include b/tests/qtest/fuzz/Makefile.include index 38b8cdd9f1..77385777ef 100644 --- a/tests/qtest/fuzz/Makefile.include +++ b/tests/qtest/fuzz/Makefile.include @@ -8,6 +8,7 @@ fuzz-obj-y += tests/qtest/fuzz/qos_fuzz.o # Targets fuzz-obj-y += tests/qtest/fuzz/i440fx_fuzz.o +fuzz-obj-y += tests/qtest/fuzz/virtio_net_fuzz.o FUZZ_CFLAGS += -I$(SRC_PATH)/tests -I$(SRC_PATH)/tests/qtest diff --git a/tests/qtest/fuzz/virtio_net_fuzz.c b/tests/qtest/fuzz/virtio_net_fuzz.c new file mode 100644 index 0000000000..e4e3e50865 --- /dev/null +++ b/tests/qtest/fuzz/virtio_net_fuzz.c @@ -0,0 +1,195 @@ +/* + * virtio-net Fuzzing Target + * + * Copyright Red Hat Inc., 2019 + * + * Authors: + * Alexander Bulekov <alxndr@bu.edu> + * + * 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 "standard-headers/linux/virtio_config.h" +#include "tests/qtest/libqtest.h" +#include "tests/qtest/libqos/virtio-net.h" +#include "fuzz.h" +#include "fork_fuzz.h" +#include "qos_fuzz.h" + + +#define QVIRTIO_NET_TIMEOUT_US (30 * 1000 * 1000) +#define QVIRTIO_RX_VQ 0 +#define QVIRTIO_TX_VQ 1 +#define QVIRTIO_CTRL_VQ 2 + +static int sockfds[2]; +static bool sockfds_initialized; + +static void virtio_net_fuzz_multi(QTestState *s, + const unsigned char *Data, size_t Size, bool check_used) +{ + typedef struct vq_action { + uint8_t queue; + uint8_t length; + uint8_t write; + uint8_t next; + uint8_t rx; + } vq_action; + + uint32_t free_head = 0; + + QGuestAllocator *t_alloc = fuzz_qos_alloc; + + QVirtioNet *net_if = fuzz_qos_obj; + QVirtioDevice *dev = net_if->vdev; + QVirtQueue *q; + vq_action vqa; + while (Size >= sizeof(vqa)) { + memcpy(&vqa, Data, sizeof(vqa)); + Data += sizeof(vqa); + Size -= sizeof(vqa); + + q = net_if->queues[vqa.queue % 3]; + + vqa.length = vqa.length >= Size ? Size : vqa.length; + + /* + * Only attempt to write incoming packets, when using the socket + * backend. Otherwise, always place the input on a virtqueue. + */ + if (vqa.rx && sockfds_initialized) { + write(sockfds[0], Data, vqa.length); + } else { + vqa.rx = 0; + uint64_t req_addr = guest_alloc(t_alloc, vqa.length); + /* + * If checking used ring, ensure that the fuzzer doesn't trigger + * trivial asserion failure on zero-zied buffer + */ + qtest_memwrite(s, req_addr, Data, vqa.length); + + + free_head = qvirtqueue_add(s, q, req_addr, vqa.length, + vqa.write, vqa.next); + qvirtqueue_add(s, q, req_addr, vqa.length, vqa.write , vqa.next); + qvirtqueue_kick(s, dev, q, free_head); + } + + /* + * normally, we could just use qvirtio_wait_used_elem, but since we + * must manually run the main-loop for all the bhs to run, we use + * this hack with flush_events(), to run the main_loop + */ + gint64 start_time = g_get_monotonic_time(); + for (;;) { + /* Run the main loop */ + qtest_clock_step(s, 100); + flush_events(s); + /* Poll the used vring only if we added to the TX or CTRL vq */ + if (check_used && !vqa.rx && q != net_if->queues[QVIRTIO_RX_VQ]) { + uint32_t got_desc_idx; + /* Input led to a virtio_error */ + if (dev->bus->get_status(dev) & VIRTIO_CONFIG_S_NEEDS_RESET) { + break; + } + if (dev->bus->get_queue_isr_status(dev, q) && + qvirtqueue_get_buf(s, q, &got_desc_idx, NULL)) { + g_assert_cmpint(got_desc_idx, ==, free_head); + break; + } + g_assert(g_get_monotonic_time() - start_time + <= QVIRTIO_NET_TIMEOUT_US); + } else { + break; + } + } + Data += vqa.length; + Size -= vqa.length; + } +} + +static void virtio_net_fork_fuzz(QTestState *s, + const unsigned char *Data, size_t Size) +{ + if (fork() == 0) { + virtio_net_fuzz_multi(s, Data, Size, false); + flush_events(s); + _Exit(0); + } else { + wait(NULL); + } +} + +static void virtio_net_fork_fuzz_check_used(QTestState *s, + const unsigned char *Data, size_t Size) +{ + if (fork() == 0) { + virtio_net_fuzz_multi(s, Data, Size, true); + flush_events(s); + _Exit(0); + } else { + wait(NULL); + } +} + +static void virtio_net_pre_fuzz(QTestState *s) +{ + qos_init_path(s); + counter_shm_init(); +} + +static void *virtio_net_test_setup_socket(GString *cmd_line, void *arg) +{ + int ret = socketpair(PF_UNIX, SOCK_STREAM, 0, sockfds); + g_assert_cmpint(ret, !=, -1); + fcntl(sockfds[0], F_SETFL, O_NONBLOCK); + sockfds_initialized = true; + g_string_append_printf(cmd_line, " -netdev socket,fd=%d,id=hs0 ", + sockfds[1]); + return arg; +} + +static void *virtio_net_test_setup_user(GString *cmd_line, void *arg) +{ + g_string_append_printf(cmd_line, " -netdev user,id=hs0 "); + return arg; +} + +static void register_virtio_net_fuzz_targets(void) +{ + fuzz_add_qos_target(&(FuzzTarget){ + .name = "virtio-net-socket", + .description = "Fuzz the virtio-net virtual queues. Fuzz incoming " + "traffic using the socket backend", + .pre_fuzz = &virtio_net_pre_fuzz, + .fuzz = virtio_net_fork_fuzz,}, + "virtio-net", + &(QOSGraphTestOptions){.before = virtio_net_test_setup_socket} + ); + + fuzz_add_qos_target(&(FuzzTarget){ + .name = "virtio-net-socket-check-used", + .description = "Fuzz the virtio-net virtual queues. Wait for the " + "descriptors to be used. Timeout may indicate improperly handled " + "input", + .pre_fuzz = &virtio_net_pre_fuzz, + .fuzz = virtio_net_fork_fuzz_check_used,}, + "virtio-net", + &(QOSGraphTestOptions){.before = virtio_net_test_setup_socket} + ); + fuzz_add_qos_target(&(FuzzTarget){ + .name = "virtio-net-slirp", + .description = "Fuzz the virtio-net virtual queues with the slirp " + " backend. Warning: May result in network traffic emitted from the " + " process. Run in an isolated network environment.", + .pre_fuzz = &virtio_net_pre_fuzz, + .fuzz = virtio_net_fork_fuzz,}, + "virtio-net", + &(QOSGraphTestOptions){.before = virtio_net_test_setup_user} + ); +} + +fuzz_target_init(register_virtio_net_fuzz_targets);
The virtio-net fuzz target feeds inputs to all three virtio-net virtqueues, and uses forking to avoid leaking state between fuzz runs. Signed-off-by: Alexander Bulekov <alxndr@bu.edu> --- tests/qtest/fuzz/Makefile.include | 1 + tests/qtest/fuzz/virtio_net_fuzz.c | 195 +++++++++++++++++++++++++++++ 2 files changed, 196 insertions(+) create mode 100644 tests/qtest/fuzz/virtio_net_fuzz.c