LibCoredump: Copy out the FooInfo structs to an aligned address

We were handing out unaligned pointers to these, which made UBSAN super
mad, copy them out to avoid that.

1 files changed, 38 insertions, 4 deletions

diff --git a/Userland/Libraries/LibCoredump/Reader.h b/Userland/Libraries/LibCoredump/Reader.h
index 3ed581a40e..aee369f5e3 100644
--- a/Userland/Libraries/LibCoredump/Reader.h
+++ b/Userland/Libraries/LibCoredump/Reader.h
@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include <AK/ByteReader.h>
 #include <AK/HashMap.h>
 #include <AK/Noncopyable.h>
 #include <AK/OwnPtr.h>
@@ -15,6 +16,24 @@
 
 namespace Coredump {
 
+struct MemoryRegionInfo {
+    ELF::Core::NotesEntryHeader header;
+    uint64_t region_start;
+    uint64_t region_end;
+    uint16_t program_header_index;
+    StringView region_name;
+
+    StringView object_name() const
+    {
+        if (region_name.contains("Loader.so"))
+            return "Loader.so"sv;
+        auto maybe_colon_index = region_name.find(':');
+        if (!maybe_colon_index.has_value())
+            return {};
+        return region_name.substring_view(0, *maybe_colon_index);
+    }
+};
+
 class Reader {
     AK_MAKE_NONCOPYABLE(Reader);
     AK_MAKE_NONMOVABLE(Reader);
@@ -40,8 +59,8 @@ public:
     const ELF::Image& image() const { return m_coredump_image; }
 
     Optional<FlatPtr> peek_memory(FlatPtr address) const;
-    ELF::Core::MemoryRegionInfo const* first_region_for_object(StringView object_name) const;
-    const ELF::Core::MemoryRegionInfo* region_containing(FlatPtr address) const;
+    Optional<MemoryRegionInfo> first_region_for_object(StringView object_name) const;
+    Optional<MemoryRegionInfo> region_containing(FlatPtr address) const;
 
     struct LibraryData {
         String name;
@@ -104,7 +123,20 @@ void Reader::for_each_memory_region_info(Func func) const
     for (; !it.at_end(); it.next()) {
         if (it.type() != ELF::Core::NotesEntryHeader::Type::MemoryRegionInfo)
             continue;
-        auto& memory_region_info = *bit_cast<const ELF::Core::MemoryRegionInfo*>(it.current());
+        ELF::Core::MemoryRegionInfo raw_memory_region_info;
+        ReadonlyBytes raw_data {
+            it.current(),
+            sizeof(raw_memory_region_info),
+        };
+        ByteReader::load(raw_data.data(), raw_memory_region_info);
+
+        MemoryRegionInfo memory_region_info {
+            raw_memory_region_info.header,
+            raw_memory_region_info.region_start,
+            raw_memory_region_info.region_end,
+            raw_memory_region_info.program_header_index,
+            { bit_cast<const char*>(raw_data.offset_pointer(raw_data.size())) },
+        };
         IterationDecision decision = func(memory_region_info);
         if (decision == IterationDecision::Break)
             return;
@@ -118,7 +150,9 @@ void Reader::for_each_thread_info(Func func) const
     for (; !it.at_end(); it.next()) {
         if (it.type() != ELF::Core::NotesEntryHeader::Type::ThreadInfo)
             continue;
-        auto& thread_info = *bit_cast<const ELF::Core::ThreadInfo*>(it.current());
+        ELF::Core::ThreadInfo thread_info;
+        ByteReader::load(bit_cast<const u8*>(it.current()), thread_info);
+
         IterationDecision decision = func(thread_info);
         if (decision == IterationDecision::Break)
             return;