Fix UBSAN reported access to withing misaligned addresses

This is can be an issue on ARM, it can cause a hang of CrashReportTest.MiniDump test on macOS.
snxd · Aug 7, 2024 · 81d5d77 · 81d5d77
1 parent ff38335
commit 81d5d77
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Showing 2 changed files with 5 additions and 3 deletions.
diff --git a/src/client/linux/minidump_writer/directory_reader.h b/src/client/linux/minidump_writer/directory_reader.h
@@ -95,9 +95,10 @@ class DirectoryReader {
 
  private:
   const int fd_;
-  bool hit_eof_;
   unsigned buf_used_;
-  uint8_t buf_[sizeof(struct kernel_dirent) + NAME_MAX + 1];
+  alignas(struct kernel_dirent)
+      uint8_t buf_[sizeof(struct kernel_dirent) + NAME_MAX + 1];
+  bool hit_eof_;
 };
 
 }  // namespace google_breakpad

diff --git a/src/common/memory_allocator.h b/src/common/memory_allocator.h
@@ -76,7 +76,8 @@ class PageAllocator {
 
     if (current_page_ && page_size_ - page_offset_ >= bytes) {
       uint8_t* const ret = current_page_ + page_offset_;
-      page_offset_ += bytes;
+      // Keep page_offset_ aligned as the CPU natural word size.
+      page_offset_ += (bytes + sizeof(uintptr_t) - 1) & (~sizeof(uintptr_t) + 1);
       if (page_offset_ == page_size_) {
         page_offset_ = 0;
         current_page_ = NULL;