Skip to content

fix: add buffer verification in GenTextFile to prevent OOB heap reads #9102

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
Ashutosh0x wants to merge 1 commit into
base: master
Choose a base branch
from
+19 −0
Open

fix: add buffer verification in GenTextFile to prevent OOB heap reads #9102

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
19 changes: 19 additions & 0 deletions src/idl_gen_text.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -447,6 +447,25 @@ const char* GenTextFile(const Parser& parser, const std::string& path,
: "SaveFile failed";
}
if (!parser.builder_.GetSize() || !parser.root_struct_def_) return nullptr;
// Verify buffer integrity before text generation to prevent OOB reads
// from corrupted vector lengths or field offsets (see #9051).
{
flatbuffers::Verifier verifier(parser.builder_.GetBufferPointer(),
parser.builder_.GetSize());
if (!parser.root_struct_def_->fixed
? !verifier.VerifyBuffer<flatbuffers::Table>(
parser.file_identifier_.length()
? parser.file_identifier_.c_str()
: nullptr)
: !verifier.VerifyBufferFromStart<flatbuffers::Table>(
parser.file_identifier_.length()
? parser.file_identifier_.c_str()
: nullptr,
parser.builder_.GetSize())) {
return "buffer failed verification, refusing to generate JSON from "
"potentially corrupt data";
}
}
std::string text;
auto err = GenText(parser, parser.builder_.GetBufferPointer(), &text);
if (err) return err;
Expand Down