libbacktrace: check if elf file paths are valid before reading them.
Bug: 25194400
Change-Id: If6e60585673226392d38fab9ad14bd7b94261316
diff --git a/libbacktrace/BacktraceOffline.cpp b/libbacktrace/BacktraceOffline.cpp
index 27dfb83..abc186b 100644
--- a/libbacktrace/BacktraceOffline.cpp
+++ b/libbacktrace/BacktraceOffline.cpp
@@ -22,7 +22,9 @@
}
#include <stdint.h>
+#include <stdio.h>
#include <string.h>
+#include <sys/stat.h>
#include <sys/types.h>
#include <ucontext.h>
#include <unistd.h>
@@ -616,7 +618,30 @@
return debug_frame;
}
+static bool IsValidElfPath(const std::string& filename) {
+ static const char elf_magic[] = {0x7f, 'E', 'L', 'F'};
+
+ struct stat st;
+ if (stat(filename.c_str(), &st) != 0 || !S_ISREG(st.st_mode)) {
+ return false;
+ }
+ FILE* fp = fopen(filename.c_str(), "reb");
+ if (fp == nullptr) {
+ return false;
+ }
+ char buf[4];
+ if (fread(buf, 4, 1, fp) != 1) {
+ fclose(fp);
+ return false;
+ }
+ fclose(fp);
+ return memcmp(buf, elf_magic, 4) == 0;
+}
+
static DebugFrameInfo* ReadDebugFrameFromFile(const std::string& filename) {
+ if (!IsValidElfPath(filename)) {
+ return nullptr;
+ }
auto owning_binary = llvm::object::createBinary(llvm::StringRef(filename));
if (owning_binary.getError()) {
return nullptr;