On 4/4/22 15:38, Rob Herring wrote: > On Thu, Mar 31, 2022 at 11:56:33AM +0200, Slawomir Stepien wrote: >> From: Slawomir Stepien <slawomir.stepien@xxxxxxxxx> >> >> Before this change, the memory pointed by fields 'overlay_tree' and >> 'fdt' will be double freed by a call to free_overlay_changeset() from >> of_overlay_apply(), when the init_overlay_changeset() fails. >> >> The first free will happen under 'err_free_tree' label and for the >> second time under 'err_free_overlay_changeset' label, where we call >> free_overlay_changeset(). >> >> This could happen for example, when you are applying an overlay to a >> target path that does not exists. >> >> By setting the pointers only when we are sure that >> init_overlay_changeset() will not fail, will prevent this double free. > > It looks to me like the free should just be moved from > init_overlay_changeset() to of_overlay_fdt_apply() where the allocation > is done. Frank? This patch is next on my list to look over. -Frank > > Also, I believe there's a bug that of_overlay_apply() should be passed > new_fdt_align rather than new_fdt. It's only a bug if we expect > overlay_changeset.fdt to point to a valid fdt rather than the memory > allocation. > > Rob
