On Thu, 12 Nov 2026 at 17:39, Christian Brauner <[email protected]> wrote: > copy_oldmem_page() maps a page of the old kernel that isn't in the > linear mapping with ioremap_cache() and copies from it without checking > whether the mapping worked. If it didn't, the copy reads from an offset > into the NULL page. That oopses unless the copy happens to be a user > copy, whose exception table entries turn the fault into a short copy. > > Return -ENOMEM like the other architectures do. read_from_oldmem() > turns that into -EFAULT like any other short copy. > > Reported-by: Chris Mason <[email protected]> > Fixes: 54c32021eb6f ("[PATCH] powerpc: Add arch-dependent copy_oldmem_page") > Cc: [email protected] > Reviewed-by: Breno Leitao <[email protected]> > Signed-off-by: Christian Brauner (Amutable) <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]> Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected] In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
