Repository navigation
[C] Bound put_<x> var data against the remaining buffer so a uint64 length cannot wrap the position - #1185
Open
slachiewicz wants to merge 1 commit into
Open
[C] Bound put_<x> var data against the remaining buffer so a uint64 length cannot wrap the position#1185slachiewicz wants to merge 1 commit into
slachiewicz wants to merge 1 commit into
Conversation
…ength cannot wrap the position. The check must stay a subtraction: pos + length wraps for a uint64 length and passes set_sbe_position().
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
With a uint64 var data length, put_(codec, src, length) advanced the position with set_sbe_position(pos + length), which can wrap, pass the bounds check and let the memcpy write past the buffer.
put_ now returns NULL with errno E100 when length exceeds buffer_length - position, a comparison that cannot wrap. This is the encode-side counterpart of #1178.
Part of #969.
Verified: CVarDataPutUint64LengthTest fails on master (negative-size-param in put_text() under ASan) and passes here; sbe-tool checkstyle and test, cppbuild and cppbuild --debug-build --sanitise-build pass.