On Tue 27-08-19 15:20:46, Alastair D'Silva wrote: > From: Alastair D'Silva <alast...@d-silva.org> > > It is possible for firmware to allocate memory ranges outside > the range of physical memory that we support (MAX_PHYSMEM_BITS).
Doesn't that count as a FW bug? Do you have any evidence of that in the field? Just wondering... > This patch adds a bounds check to ensure that any hotplugged > memory is addressable. > > Signed-off-by: Alastair D'Silva <alast...@d-silva.org> > --- > arch/powerpc/mm/mem.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c > index 9191a66b3bc5..de18fb73de30 100644 > --- a/arch/powerpc/mm/mem.c > +++ b/arch/powerpc/mm/mem.c > @@ -111,6 +111,9 @@ int __ref arch_add_memory(int nid, u64 start, u64 size, > unsigned long nr_pages = size >> PAGE_SHIFT; > int rc; > > + if ((start + size - 1) >> MAX_PHYSMEM_BITS) > + return -EINVAL; > + > resize_hpt_for_hotplug(memblock_phys_mem_size()); > > start = (unsigned long)__va(start); > -- > 2.21.0 -- Michal Hocko SUSE Labs
