Add overflow checks in Memory objects.
Also change one of the reads to be explicitly ReadField instead of an
overloaded Read function.
Bug: 23762183
Test: Passes new unit tests.
Change-Id: Id848f7b632f67df0c5b7318d9e588942cfd2099a
diff --git a/libunwindstack/Memory.h b/libunwindstack/Memory.h
index c5316a1..f9f6d56 100644
--- a/libunwindstack/Memory.h
+++ b/libunwindstack/Memory.h
@@ -17,6 +17,7 @@
#ifndef _LIBUNWINDSTACK_MEMORY_H
#define _LIBUNWINDSTACK_MEMORY_H
+#include <assert.h>
#include <stdint.h>
#include <sys/types.h>
#include <unistd.h>
@@ -33,9 +34,16 @@
virtual bool Read(uint64_t addr, void* dst, size_t size) = 0;
- inline bool Read(uint64_t addr, void* start, void* field, size_t size) {
- return Read(addr + reinterpret_cast<uintptr_t>(field) - reinterpret_cast<uintptr_t>(start),
- field, size);
+ inline bool ReadField(uint64_t addr, void* start, void* field, size_t size) {
+ if (reinterpret_cast<uintptr_t>(field) < reinterpret_cast<uintptr_t>(start)) {
+ return false;
+ }
+ uint64_t offset = reinterpret_cast<uintptr_t>(field) - reinterpret_cast<uintptr_t>(start);
+ if (__builtin_add_overflow(addr, offset, &offset)) {
+ return false;
+ }
+ // The read will check if offset + size overflows.
+ return Read(offset, field, size);
}
inline bool Read32(uint64_t addr, uint32_t* dst) {
@@ -103,6 +111,9 @@
pid_t pid() { return pid_; }
+ protected:
+ virtual bool PtraceRead(uint64_t addr, long* value);
+
private:
pid_t pid_;
};
@@ -118,15 +129,12 @@
class MemoryRange : public Memory {
public:
MemoryRange(Memory* memory, uint64_t begin, uint64_t end)
- : memory_(memory), begin_(begin), length_(end - begin_) {}
+ : memory_(memory), begin_(begin), length_(end - begin) {
+ assert(end > begin);
+ }
virtual ~MemoryRange() { delete memory_; }
- inline bool Read(uint64_t addr, void* dst, size_t size) override {
- if (addr + size <= length_) {
- return memory_->Read(addr + begin_, dst, size);
- }
- return false;
- }
+ bool Read(uint64_t addr, void* dst, size_t size) override;
private:
Memory* memory_;