[-Wunsafe-buffer-usage] Fix a potential overflow bug reported by #126334 #129169
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
…#126334 `MeasureTokenLength` may return an unsigned 0 representing failure in obtaining length of a token. The analysis now gives up on such cases. Otherwise, there might be issues caused by unsigned integer "overflow".
ziqingluo-90
requested review from
haoNoQ,
jkorous-apple,
malavikasamak,
shafik and
t-rasmud
llvmbot
added
clang
Contributor
Author
|
CC: @dtarditi |
Member
|
@llvm/pr-subscribers-clang @llvm/pr-subscribers-clang-analysis Author: Ziqing Luo (ziqingluo-90) Changes
Full diff: https://github.com/llvm/llvm-project/pull/129169.diff 1 Files Affected:
diff --git a/clang/lib/Analysis/UnsafeBufferUsage.cpp b/clang/lib/Analysis/UnsafeBufferUsage.cpp
index ff4f940a596e3..12e99143cb148 100644
--- a/clang/lib/Analysis/UnsafeBufferUsage.cpp
+++ b/clang/lib/Analysis/UnsafeBufferUsage.cpp
@@ -2364,12 +2364,13 @@ template <typename NodeTy>
static std::optional<SourceLocation>
getEndCharLoc(const NodeTy *Node, const SourceManager &SM,
const LangOptions &LangOpts) {
- unsigned TkLen = Lexer::MeasureTokenLength(Node->getEndLoc(), SM, LangOpts);
- SourceLocation Loc = Node->getEndLoc().getLocWithOffset(TkLen - 1);
-
- if (Loc.isValid())
- return Loc;
+ if (unsigned TkLen =
+ Lexer::MeasureTokenLength(Node->getEndLoc(), SM, LangOpts)) {
+ SourceLocation Loc = Node->getEndLoc().getLocWithOffset(TkLen - 1);
+ if (Loc.isValid())
+ return Loc;
+ }
return std::nullopt;
}
|
shafik
reviewed
Feb 28, 2025
Collaborator
shafik
left a comment
shafik
left a comment
There was a problem hiding this comment.
LGTM, thank you for the quick fix!
cheezeburglar
pushed a commit
to cheezeburglar/llvm-project
that referenced
this pull request
Feb 28, 2025
…#126334 (llvm#129169) `MeasureTokenLength` may return an unsigned 0 representing failure in obtaining length of a token. The analysis now gives up on such cases. Otherwise, there might be issues caused by unsigned integer "overflow".
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
4 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.
MeasureTokenLengthmay return an unsigned 0 representing failure in obtaining length of a token. The analysis now gives up on such cases. Otherwise, there might be issues caused by unsigned integer "overflow".