[-Wunsafe-buffer-usage] Fix a potential overflow bug reported by #126334 #129169
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…#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,
malavikasamak,
shafik,
t-rasmud and
jkorous-apple
llvmbot
added
clang
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CC: @dtarditi |
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@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;
}
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shafik
reviewed
Feb 28, 2025
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".
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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".