From 4e5a013cb03ef7b3256d5172322262d70a5e4d1f Mon Sep 17 00:00:00 2001 From: Alex Langford Date: Thu, 16 Oct 2025 14:46:28 -0700 Subject: [PATCH] [lldb] Fix misaligned loads violation in DataExtractor The implementation of the templated `Get` function contains UB. For example, the "GetDoubleUnaligned" unit test causes `Get` to perform an unaligned 8 byte read. This violates the `double` alignment requirement. Furthermore, it violates strict aliasing rules in C++. (We construct a `const double *` from a `const uint8_t *` and perform a read on the resulting double pointer). DataExtractor should be able to read unaligned data to deal with different data formats, but we need to be careful to not perform unaligned reads/writes or violate strict aliasing rules. rdar://160385383 --- lldb/include/lldb/Utility/DataExtractor.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lldb/include/lldb/Utility/DataExtractor.h b/lldb/include/lldb/Utility/DataExtractor.h index 0b7e771ed4f86..b4960f5e87c85 100644 --- a/lldb/include/lldb/Utility/DataExtractor.h +++ b/lldb/include/lldb/Utility/DataExtractor.h @@ -994,7 +994,7 @@ class DataExtractor { constexpr size_t src_size = sizeof(T); T val = fail_value; - const T *src = static_cast(GetData(offset_ptr, src_size)); + const void *src = GetData(offset_ptr, src_size); if (!src) return val;