of: overlay: Fix out-of-bounds write in init_overlay_changeset()
If an overlay has no "__symbols__" node, but it has nodes without "__overlay__" subnodes at the end (e.g. a "__fixups__" node), after filling in all fragments for nodes with "__overlay__" subnodes, "fragment = &fragments[cnt]" will point beyond the end of the allocated array. Hence writing to "fragment->overlay" will overwrite unallocated memory, which may lead to a crash later. Fix this by deferring both the assignment to "fragment" and the offending write afterwards until we know for sure the node has an "__overlay__" subnode, and thus a valid entry in "fragments[]". Fixes: 61b4de4e ("of: overlay: minor restructuring") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Rob Herring <robh@kernel.org>
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