tests/qtest/fuzz/virtio_scsi_fuzz.c

   1 /*
   2  * virtio-serial Fuzzing Target
   3  *
   4  * Copyright Red Hat Inc., 2019
   5  *
   6  * Authors:
   7  *  Alexander Bulekov   <alxndr@bu.edu>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  10  * See the COPYING file in the top-level directory.
  11  */
  12
  13 #include "qemu/osdep.h"
  14
  15 #include "tests/qtest/libqtest.h"
  16 #include "tests/qtest/libqos/virtio-scsi.h"
  17 #include "tests/qtest/libqos/virtio.h"
  18 #include "tests/qtest/libqos/virtio-pci.h"
  19 #include "standard-headers/linux/virtio_ids.h"
  20 #include "standard-headers/linux/virtio_pci.h"
  21 #include "standard-headers/linux/virtio_scsi.h"
  22 #include "fuzz.h"
  23 #include "qos_fuzz.h"
  24
  25 #define PCI_SLOT                0x02
  26 #define PCI_FN                  0x00
  27 #define QVIRTIO_SCSI_TIMEOUT_US (1 * 1000 * 1000)
  28
  29 #define MAX_NUM_QUEUES 64
  30
  31 /* Based on tests/virtio-scsi-test.c */
  32 typedef struct {
  33     int num_queues;
  34     QVirtQueue *vq[MAX_NUM_QUEUES + 2];
  35 } QVirtioSCSIQueues;
  36
  37 static QVirtioSCSIQueues *qvirtio_scsi_init(QVirtioDevice *dev, uint64_t mask)
  38 {
  39     QVirtioSCSIQueues *vs;
  40     uint64_t feat;
  41     int i;
  42
  43     vs = g_new0(QVirtioSCSIQueues, 1);
  44
  45     feat = qvirtio_get_features(dev);
  46     if (mask) {
  47         feat &= ~QVIRTIO_F_BAD_FEATURE | mask;
  48     } else {
  49         feat &= ~(QVIRTIO_F_BAD_FEATURE | (1ull << VIRTIO_RING_F_EVENT_IDX));
  50     }
  51     qvirtio_set_features(dev, feat);
  52
  53     vs->num_queues = qvirtio_config_readl(dev, 0);
  54
  55     for (i = 0; i < vs->num_queues + 2; i++) {
  56         vs->vq[i] = qvirtqueue_setup(dev, fuzz_qos_alloc, i);
  57     }
  58
  59     qvirtio_set_driver_ok(dev);
  60
  61     return vs;
  62 }
  63
  64 static void virtio_scsi_fuzz(QTestState *s, QVirtioSCSIQueues* queues,
  65         const unsigned char *Data, size_t Size)
  66 {
  67     /*
  68      * Data is a sequence of random bytes. We split them up into "actions",
  69      * followed by data:
  70      * [vqa][dddddddd][vqa][dddd][vqa][dddddddddddd] ...
  71      * The length of the data is specified by the preceding vqa.length
  72      */
  73     typedef struct vq_action {
  74         uint8_t queue;
  75         uint8_t length;
  76         uint8_t write;
  77         uint8_t next;
  78         uint8_t kick;
  79     } vq_action;
  80
  81     /* Keep track of the free head for each queue we interact with */
  82     bool vq_touched[MAX_NUM_QUEUES + 2] = {0};
  83     uint32_t free_head[MAX_NUM_QUEUES + 2];
  84
  85     QGuestAllocator *t_alloc = fuzz_qos_alloc;
  86
  87     QVirtioSCSI *scsi = fuzz_qos_obj;
  88     QVirtioDevice *dev = scsi->vdev;
  89     QVirtQueue *q;
  90     vq_action vqa;
  91     while (Size >= sizeof(vqa)) {
  92         /* Copy the action, so we can normalize length, queue and flags */
  93         memcpy(&vqa, Data, sizeof(vqa));
  94
  95         Data += sizeof(vqa);
  96         Size -= sizeof(vqa);
  97
  98         vqa.queue = vqa.queue % queues->num_queues;
  99         /* Cap length at the number of remaining bytes in data */
 100         vqa.length = vqa.length >= Size ? Size : vqa.length;
 101         vqa.write = vqa.write & 1;
 102         vqa.next = vqa.next & 1;
 103         vqa.kick = vqa.kick & 1;
 104
 105
 106         q = queues->vq[vqa.queue];
 107
 108         /* Copy the data into ram, and place it on the virtqueue */
 109         uint64_t req_addr = guest_alloc(t_alloc, vqa.length);
 110         qtest_memwrite(s, req_addr, Data, vqa.length);
 111         if (vq_touched[vqa.queue] == 0) {
 112             vq_touched[vqa.queue] = 1;
 113             free_head[vqa.queue] = qvirtqueue_add(s, q, req_addr, vqa.length,
 114                     vqa.write, vqa.next);
 115         } else {
 116             qvirtqueue_add(s, q, req_addr, vqa.length, vqa.write , vqa.next);
 117         }
 118
 119         if (vqa.kick) {
 120             qvirtqueue_kick(s, dev, q, free_head[vqa.queue]);
 121             free_head[vqa.queue] = 0;
 122         }
 123         Data += vqa.length;
 124         Size -= vqa.length;
 125     }
 126     /* In the end, kick each queue we interacted with */
 127     for (int i = 0; i < MAX_NUM_QUEUES + 2; i++) {
 128         if (vq_touched[i]) {
 129             qvirtqueue_kick(s, dev, queues->vq[i], free_head[i]);
 130         }
 131     }
 132 }
 133
 134 static void virtio_scsi_with_flag_fuzz(QTestState *s,
 135         const unsigned char *Data, size_t Size)
 136 {
 137     QVirtioSCSI *scsi = fuzz_qos_obj;
 138     static QVirtioSCSIQueues *queues;
 139
 140     if (Size >= sizeof(uint64_t)) {
 141         queues = qvirtio_scsi_init(scsi->vdev, *(uint64_t *)Data);
 142         virtio_scsi_fuzz(s, queues,
 143                 Data + sizeof(uint64_t), Size - sizeof(uint64_t));
 144         flush_events(s);
 145     }
 146     fuzz_reset(s);
 147 }
 148
 149 static void virtio_scsi_pre_fuzz(QTestState *s)
 150 {
 151     qos_init_path(s);
 152 }
 153
 154 static void *virtio_scsi_test_setup(GString *cmd_line, void *arg)
 155 {
 156     g_string_append(cmd_line,
 157                     " -drive file=blkdebug::null-co://,"
 158                     "file.image.read-zeroes=on,"
 159                     "if=none,id=dr1,format=raw,file.align=4k "
 160                     "-device scsi-hd,drive=dr1,lun=0,scsi-id=1");
 161     return arg;
 162 }
 163
 164
 165 static void register_virtio_scsi_fuzz_targets(void)
 166 {
 167     fuzz_add_qos_target(&(FuzzTarget){
 168                 .name = "virtio-scsi-flags-fuzz",
 169                 .description = "Fuzz the virtio-scsi virtual queues. "
 170                 "Also fuzzes the virtio flags",
 171                 .pre_fuzz = &virtio_scsi_pre_fuzz,
 172                 .fuzz = virtio_scsi_with_flag_fuzz,},
 173                 "virtio-scsi",
 174                 &(QOSGraphTestOptions){.before = virtio_scsi_test_setup}
 175                 );
 176 }
 177
 178 fuzz_target_init(register_virtio_scsi_fuzz_targets);