BigfootDev/flatbuffers
1
0
Fork 1
mirror of https://github.com/google/flatbuffers.git synced 2026-06-26 16:52:40 +00:00
Code Issues Packages Projects Releases Wiki Activity

Added alignment checking to FlexBuffers verifier

Browse Source
This commit is contained in:
Wouter van Oortmerssen
2021-12-14 11:20:15 -08:00
parent 5a0c3366c3
commit d8b7041d7e
1 changed files with 10 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
include/flatbuffers/flexbuffers.h
View File

@@ -1645,6 +1645,7 @@ class Verifier FLATBUFFERS_FINAL_CLASS {
// comes at the cost of using additional memory the same size of // comes at the cost of using additional memory the same size of
// the buffer being verified, so it is by default off. // the buffer being verified, so it is by default off.
std::vector<uint8_t> *reuse_tracker = nullptr, std::vector<uint8_t> *reuse_tracker = nullptr,
bool _check_alignment = true,
size_t max_depth = 64) size_t max_depth = 64)
: buf_(buf), : buf_(buf),
size_(buf_len), size_(buf_len),
@@ -1652,6 +1653,7 @@ class Verifier FLATBUFFERS_FINAL_CLASS {
max_depth_(max_depth), max_depth_(max_depth),
num_vectors_(0), num_vectors_(0),
max_vectors_(buf_len), max_vectors_(buf_len),
check_alignment_(_check_alignment),
reuse_tracker_(reuse_tracker) { reuse_tracker_(reuse_tracker) {
FLATBUFFERS_ASSERT(size_ < FLATBUFFERS_MAX_BUFFER_SIZE); FLATBUFFERS_ASSERT(size_ < FLATBUFFERS_MAX_BUFFER_SIZE);
if (reuse_tracker_) { if (reuse_tracker_) {
@@ -1701,6 +1703,11 @@ class Verifier FLATBUFFERS_FINAL_CLASS {
off <= static_cast<uint64_t>(p - buf_); off <= static_cast<uint64_t>(p - buf_);
} }
bool VerifyAlignment(const uint8_t *p, size_t size) const {
auto o = static_cast<size_t>(p - buf_);
return Check((o & (size - 1)) == 0 || !check_alignment_);
}
// Macro, since we want to escape from parent function & use lazy args. // Macro, since we want to escape from parent function & use lazy args.
#define FLEX_CHECK_VERIFIED(P, PACKED_TYPE) \ #define FLEX_CHECK_VERIFIED(P, PACKED_TYPE) \
if (reuse_tracker_) { \ if (reuse_tracker_) { \
@@ -1795,6 +1802,8 @@ class Verifier FLATBUFFERS_FINAL_CLASS {
if (!VerifyOffset(off, r.data_)) if (!VerifyOffset(off, r.data_))
return false; return false;
auto p = r.Indirect(); auto p = r.Indirect();
if (!VerifyAlignment(p, r.byte_width_))
return false;
switch (r.type_) { switch (r.type_) {
case FBT_INDIRECT_INT: case FBT_INDIRECT_INT:
case FBT_INDIRECT_UINT: case FBT_INDIRECT_UINT:
@@ -1862,6 +1871,7 @@ class Verifier FLATBUFFERS_FINAL_CLASS {
const size_t max_depth_; const size_t max_depth_;
size_t num_vectors_; size_t num_vectors_;
const size_t max_vectors_; const size_t max_vectors_;
bool check_alignment_;
std::vector<uint8_t> *reuse_tracker_; std::vector<uint8_t> *reuse_tracker_;
}; };