C++: Fix CWE-119 memcpy tests #20876
Merged
Conversation
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
sizeof(pointer) only gives the pointer size, not the buffer size, so use explicit 10/20 lengths in tests.cpp and update OverflowBuffer.expected to accept the resulting memcpy diagnostics. Signed-off-by: Mingjie Shen <shen497@purdue.edu>
jketema
reviewed
Nov 21, 2025
Contributor
jketema
left a comment
jketema
left a comment
There was a problem hiding this comment.
Thanks for noticing this. We would like to be a bit more explicit, see below. Otherwise this looks fine.
Comment on lines
33
to
36
| memcpy(bigbuffer, smallbuffer, 10); // GOOD | ||
| memcpy(bigbuffer, smallbuffer, 20); // BAD: over-read | ||
| memcpy(smallbuffer, bigbuffer, 10); // GOOD | ||
| memcpy(smallbuffer, bigbuffer, 20); // BAD: over-write |
Contributor
There was a problem hiding this comment.
We would prefer the following here:
Suggested change
| memcpy(bigbuffer, smallbuffer, 10); // GOOD | |
| memcpy(bigbuffer, smallbuffer, 20); // BAD: over-read | |
| memcpy(smallbuffer, bigbuffer, 10); // GOOD | |
| memcpy(smallbuffer, bigbuffer, 20); // BAD: over-write | |
| memcpy(bigbuffer, smallbuffer, sizeof(char) * 10); // GOOD | |
| memcpy(bigbuffer, smallbuffer, sizeof(char) * 20); // BAD: over-read | |
| memcpy(smallbuffer, bigbuffer, sizeof(char) * 10); // GOOD | |
| memcpy(smallbuffer, bigbuffer, sizeof(char) * 20); // BAD: over-write |
cpp/ql/test/query-tests/Security/CWE/CWE-119/semmle/tests/tests.cpp
Outdated
Show resolved
Hide resolved
Signed-off-by: Mingjie Shen <shen497@purdue.edu>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
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Outdated suggestions cannot be applied.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.
sizeof(pointer) only gives the pointer size, not the buffer size, so use explicit 10/20 lengths in tests.cpp and update OverflowBuffer.expected to accept the resulting memcpy diagnostics.