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104 lines
3.0 KiB
104 lines
3.0 KiB
/**
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* Copyright (C) 2020 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <stdlib.h>
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#include "../includes/common.h"
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//This PoC is only for 32-bit builds
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#if _32_BIT
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#include <unistd.h>
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#include <string.h>
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#include <dlfcn.h>
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#define MAX_STRLEN 256
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#define LOOP_COUNT 10
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#define LIB_NAME "/system/lib/libandroid.so"
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int runDlopenDlcloseLibraryLoop(char *libName, unsigned char count) {
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while (count) {
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void *lib_handle = dlopen(libName, RTLD_NOW);
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if (!lib_handle) {
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return EXIT_FAILURE;
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}
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if (dlclose(lib_handle)) {
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return EXIT_FAILURE;
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}
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count--;
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}
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return EXIT_SUCCESS;
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}
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int getMemoryUsage(unsigned long *memUsage) {
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char cmd[MAX_STRLEN];
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char buf[MAX_STRLEN];
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memset(cmd, 0, MAX_STRLEN);
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memset(buf, 0, MAX_STRLEN);
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sprintf(cmd, "cat /proc/%d/maps | grep anon:linker_alloc]", getpid());
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FILE *fpMem = popen(cmd, "r");
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if (!fpMem) {
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return EXIT_FAILURE;
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}
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unsigned long totalMemUsage = 0;
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while (fgets(buf, MAX_STRLEN, fpMem) != NULL) {
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unsigned long mem1 = 0;
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unsigned long mem2 = 0;
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int numOfItemsRead = sscanf(buf, "%lx-%lx", &mem1, &mem2);
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if (numOfItemsRead < 2) {
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pclose(fpMem);
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return EXIT_FAILURE;
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}
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totalMemUsage += mem2 - mem1;
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}
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pclose(fpMem);
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*memUsage = totalMemUsage;
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return EXIT_SUCCESS;
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}
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#endif /* _32_BIT */
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int main() {
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//This PoC is only for 32-bit builds
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#if _32_BIT
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/* Memory usage is expected to rise during first few dlopen-dlcose pairs */
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/* due to linker initializations. Hence memory is not tracked during */
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/* first few dlopen-dlcose pairs. */
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if (runDlopenDlcloseLibraryLoop(LIB_NAME, LOOP_COUNT)) {
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return EXIT_FAILURE;
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}
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/* The linker specific initializations should be complete. Hence Memory */
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/* usage is tracked from this point onwards. Further dlopen-dlcose pairs */
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/* are not expected to increase memory usage */
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unsigned long memUsageBefore = 0;
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if (getMemoryUsage(&memUsageBefore)) {
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return EXIT_FAILURE;
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}
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if (runDlopenDlcloseLibraryLoop(LIB_NAME, LOOP_COUNT)) {
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return EXIT_FAILURE;
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}
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unsigned long memUsageAfter = 0;
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if (getMemoryUsage(&memUsageAfter)) {
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return EXIT_FAILURE;
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}
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if (memUsageBefore != memUsageAfter) {
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return EXIT_VULNERABLE;
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}
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#endif /* _32_BIT */
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return EXIT_SUCCESS;
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}
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