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I replied > > earlier but my email got eaten on the way out. > > > > What happened here is that the zero day bot emails go to me first and > > then I review them or forward them depending on if they're a real > > issue or not. > > > > Here it's a false postive because it's set and used if the > > (src_vma->vm_flags & VM_PFNMAP) flag is set. Smatch doesn't parse > > this correctly. I've been meaning to fix this in Smatch for a > > while. > > There is a slight complication (on top of the VM_PFNMAP checks): > > If "src_vma->vm_flags & VM_PAT" we > * set pfn > * set dst_vma->vm_flags |= VM_PFNMAP > > Then, we only consume the pfn if "dst_vma->vm_flags & VM_PFNMAP" > > While we won't be using the uninitialized pfn (good), we'd still pass an > uninitialized pfn, which IIRC is UB; likely nothing happens on GCC clang, > but we better handle it. > > So that should better be changed; I'll send a fix. Maybe just worth setting pfn = 0 _as well_ in the caller, belts + braces maybe? I mean the patch is already upstream at dc84bc2aba85. So I guess these fixes are intended for rc generally? > > Thanks! > > -- > Cheers, > > David / dhildenb >