libbacktrace: check if elf file paths are valid before reading them. (2ad59db7) · Commits · e / os / android_system_core

libbacktrace/BacktraceOffline.cpp

+25 −0

Original line number	Original line	Diff line number	Diff line
	@@ -22,7 +22,9 @@ extern "C" {
	}		}

	#include <stdint.h>		#include <stdint.h>
			#include <stdio.h>
	#include <string.h>		#include <string.h>
			#include <sys/stat.h>
	#include <sys/types.h>		#include <sys/types.h>
	#include <ucontext.h>		#include <ucontext.h>
	#include <unistd.h>		#include <unistd.h>
	@@ -616,7 +618,30 @@ DebugFrameInfo* ReadDebugFrameFromELFFile(const llvm::object::ELFFile<ELFT>* elf
	return debug_frame;		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) {		static DebugFrameInfo* ReadDebugFrameFromFile(const std::string& filename) {
			if (!IsValidElfPath(filename)) {
			return nullptr;
			}
	auto owning_binary = llvm::object::createBinary(llvm::StringRef(filename));		auto owning_binary = llvm::object::createBinary(llvm::StringRef(filename));
	if (owning_binary.getError()) {		if (owning_binary.getError()) {
	return nullptr;		return nullptr;