trusty: Fuzzer for ConfirmationUI messages

ConfirmationUI messages are a higher-level abstraction than TIPC
messages (which is what TIPC fuzzer fuzzes).

Bug: 174402999
Test: trusty_confirmationui_msg_fuzzer
Change-Id: I1e1e2c7070b87b78d6236993330df65202840ce6

trusty/confirmationui/fuzz/Android.bp

@@ -27,3 +27,17 @@ cc_fuzz {
     ],
 
 }
+
+cc_fuzz {
+    name: "trusty_confirmationui_msg_fuzzer",
+    defaults: ["trusty_fuzzer_defaults"],
+    srcs: ["msg_fuzzer.cpp"],
+    include_dirs: ["system/core/trusty/confirmationui/include"],
+    shared_libs: [
+        "libdmabufheap",
+    ],
+
+    // The initial corpus for this fuzzer was derived by dumping messages from/to
+    // HAL to/from TA triggered by VtsHalConfirmationUIV1_0TargetTest.
+    corpus: ["msg_corpus/*"],
+}

trusty/confirmationui/fuzz/msg_fuzzer.cpp

@@ -0,0 +1,173 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <BufferAllocator/BufferAllocator.h>
+#include <TrustyIpc.h>
+#include <iostream>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <time.h>
+#include <trusty/coverage/coverage.h>
+#include <trusty/fuzz/counters.h>
+#include <trusty/fuzz/utils.h>
+#include <trusty/tipc.h>
+#include <unistd.h>
+
+using android::trusty::coverage::CoverageRecord;
+using android::trusty::fuzz::ExtraCounters;
+using android::trusty::fuzz::TrustyApp;
+
+#define countof(arr) (sizeof(arr) / sizeof(arr[0]))
+
+#define TIPC_DEV "/dev/trusty-ipc-dev0"
+#define CONFIRMATIONUI_PORT "com.android.trusty.confirmationui"
+#define CONFIRMATIONUI_MODULE_NAME "confirmationui.syms.elf"
+
+/* A request to render to screen may take a while. */
+const size_t kTimeoutSeconds = 30;
+
+/* ConfirmationUI TA's UUID is 7dee2364-c036-425b-b086-df0f6c233c1b */
+static struct uuid confirmationui_uuid = {
+    0x7dee2364,
+    0xc036,
+    0x425b,
+    {0xb0, 0x86, 0xdf, 0x0f, 0x6c, 0x23, 0x3c, 0x1b},
+};
+
+static CoverageRecord record(TIPC_DEV, &confirmationui_uuid, CONFIRMATIONUI_MODULE_NAME);
+
+static android::base::unique_fd dma_buf;
+static void* shm_base;
+
+extern "C" int LLVMFuzzerInitialize(int* /* argc */, char*** /* argv */) {
+    auto ret = record.Open();
+    if (!ret.ok()) {
+        std::cerr << ret.error() << std::endl;
+        exit(-1);
+    }
+
+    BufferAllocator allocator;
+    dma_buf.reset(allocator.Alloc(kDmabufSystemHeapName, CONFIRMATIONUI_MAX_MSG_SIZE));
+    if (dma_buf < 0) {
+        std::cerr << "Failed to allocate dma_buf" << std::endl;
+        exit(-1);
+    }
+
+    shm_base = mmap(0, CONFIRMATIONUI_MAX_MSG_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, dma_buf, 0);
+    if (shm_base == MAP_FAILED) {
+        std::cerr << "Failed to mmap() dma_buf" << std::endl;
+        exit(-1);
+    }
+
+    return 0;
+}
+
+static bool Init(int chan, int dma_buf) {
+    confirmationui_hdr hdr = {
+        .cmd = CONFIRMATIONUI_CMD_INIT,
+    };
+    confirmationui_init_req args = {
+        .shm_len = CONFIRMATIONUI_MAX_MSG_SIZE,
+    };
+    iovec iov[] = {
+        {
+            .iov_base = &hdr,
+            .iov_len = sizeof(hdr),
+        },
+        {
+            .iov_base = &args,
+            .iov_len = sizeof(args),
+        },
+    };
+    trusty_shm shm = {
+        .fd = dma_buf,
+        .transfer = TRUSTY_SHARE,
+    };
+
+    int rc = tipc_send(chan, iov, countof(iov), &shm, 1);
+    if (rc != static_cast<int>(sizeof(hdr) + sizeof(args))) {
+        return false;
+    }
+
+    rc = read(chan, &hdr, sizeof(hdr));
+    if (rc != static_cast<int>(sizeof(hdr))) {
+        return false;
+    }
+
+    return true;
+}
+
+static bool Msg(int chan, const uint8_t* data, size_t size) {
+    confirmationui_hdr hdr = {
+        .cmd = CONFIRMATIONUI_CMD_MSG,
+    };
+    confirmationui_msg_args args = {
+        .msg_len = static_cast<uint32_t>(size),
+    };
+    iovec iov[] = {
+        {
+            .iov_base = &hdr,
+            .iov_len = sizeof(hdr),
+        },
+        {
+            .iov_base = &args,
+            .iov_len = sizeof(args),
+        },
+    };
+
+    memset(shm_base, 0, CONFIRMATIONUI_MAX_MSG_SIZE);
+    memcpy(shm_base, data, size);
+
+    int rc = tipc_send(chan, iov, countof(iov), NULL, 0);
+    if (rc != static_cast<int>(sizeof(hdr) + sizeof(args))) {
+        return false;
+    }
+
+    rc = readv(chan, iov, countof(iov));
+    if (rc != static_cast<int>(sizeof(hdr) + sizeof(args))) {
+        return false;
+    }
+
+    return true;
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+    ExtraCounters counters(&record);
+    counters.Reset();
+
+    TrustyApp ta(TIPC_DEV, CONFIRMATIONUI_PORT);
+    auto ret = ta.Connect();
+    if (!ret.ok()) {
+        android::trusty::fuzz::Abort();
+    }
+    int chan = *ta.GetRawFd();
+
+    alarm(kTimeoutSeconds);
+    bool success = Init(chan, dma_buf);
+    alarm(0);
+    if (!success) {
+        android::trusty::fuzz::Abort();
+    }
+
+    alarm(kTimeoutSeconds);
+    success = Msg(chan, data, size);
+    alarm(0);
+    if (!success) {
+        android::trusty::fuzz::Abort();
+    }
+
+    return 0;
+}