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[lldb] Fix use after free on ModuleList::RemoveSharedModuleIfOrphaned #155331

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[lldb] Fix use after free on ModuleList::RemoveSharedModuleIfOrphaned #155331

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5 changes: 4 additions & 1 deletion lldb/source/Target/Target.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2564,9 +2564,12 @@ ModuleSP Target::GetOrCreateModule(const ModuleSpec &orig_module_spec,
m_images.Append(module_sp, notify);

for (ModuleSP &old_module_sp : replaced_modules) {
auto use_count = old_module_sp.use_count();
Module *old_module_ptr = old_module_sp.get();
old_module_sp.reset();
ModuleList::RemoveSharedModuleIfOrphaned(old_module_ptr);
// If the use count was one, this was not in the shared module list.
if (use_count > 1)
ModuleList::RemoveSharedModuleIfOrphaned(old_module_ptr);
Comment on lines +2567 to +2572
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Why does RemoveSharedModuleIfOrphaned take a raw pointer and not the ModuleSP? If it did, then we could just check if the SP is valid (like Remove does) and avoid yet another place where we check the use count.

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I realize that this isn't enough to address the issue. But I think this shows what a bad idea it is to mix raw pointers, shared pointer references and references.

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If RemoveSharedModuleIfOrphaned takes a shared pointer we have to account for the caller also having a shared pointer to decide whether the module is an orphan or not, which would probably be more confusing.

}
} else
module_sp.reset();
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