| Message ID | 20190910025225.25904-3-alastair@au1.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add bounds check for Hotplugged memory | expand |
On 10.09.19 04:52, Alastair D'Silva wrote: > From: Alastair D'Silva <alastair@d-silva.org> > > The call to check_hotplug_memory_addressable() validates that the memory > is fully addressable. > > Without this call, it is possible that we may remap pages that is > not physically addressable, resulting in bogus section numbers > being returned from __section_nr(). > > Signed-off-by: Alastair D'Silva <alastair@d-silva.org> > --- > mm/memremap.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/mm/memremap.c b/mm/memremap.c > index 86432650f829..fd00993caa3e 100644 > --- a/mm/memremap.c > +++ b/mm/memremap.c > @@ -269,6 +269,13 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) > > mem_hotplug_begin(); > > + error = check_hotplug_memory_addressable(res->start, > + resource_size(res)); > + if (error) { > + mem_hotplug_done(); > + goto err_checkrange; > + } > + No need to check under the memory hotplug lock. > /* > * For device private memory we call add_pages() as we only need to > * allocate and initialize struct page for the device memory. More- > @@ -324,6 +331,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) > > err_add_memory: > kasan_remove_zero_shadow(__va(res->start), resource_size(res)); > + err_checkrange: > err_kasan: > untrack_pfn(NULL, PHYS_PFN(res->start), resource_size(res)); > err_pfn_remap: >
> -----Original Message----- > From: David Hildenbrand <david@redhat.com> > Sent: Tuesday, 10 September 2019 5:39 PM > To: Alastair D'Silva <alastair@au1.ibm.com>; alastair@d-silva.org > Cc: Andrew Morton <akpm@linux-foundation.org>; Oscar Salvador > <osalvador@suse.com>; Michal Hocko <mhocko@suse.com>; Pavel Tatashin > <pasha.tatashin@soleen.com>; Dan Williams <dan.j.williams@intel.com>; > Wei Yang <richard.weiyang@gmail.com>; Qian Cai <cai@lca.pw>; Jason > Gunthorpe <jgg@ziepe.ca>; Logan Gunthorpe <logang@deltatee.com>; Ira > Weiny <ira.weiny@intel.com>; linux-mm@kvack.org; linux- > kernel@vger.kernel.org > Subject: Re: [PATCH 2/2] mm: Add a bounds check in > devm_memremap_pages() > > On 10.09.19 04:52, Alastair D'Silva wrote: > > From: Alastair D'Silva <alastair@d-silva.org> > > > > The call to check_hotplug_memory_addressable() validates that the > > memory is fully addressable. > > > > Without this call, it is possible that we may remap pages that is not > > physically addressable, resulting in bogus section numbers being > > returned from __section_nr(). > > > > Signed-off-by: Alastair D'Silva <alastair@d-silva.org> > > --- > > mm/memremap.c | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/mm/memremap.c b/mm/memremap.c index > > 86432650f829..fd00993caa3e 100644 > > --- a/mm/memremap.c > > +++ b/mm/memremap.c > > @@ -269,6 +269,13 @@ void *devm_memremap_pages(struct device > *dev, > > struct dev_pagemap *pgmap) > > > > mem_hotplug_begin(); > > > > + error = check_hotplug_memory_addressable(res->start, > > + resource_size(res)); > > + if (error) { > > + mem_hotplug_done(); > > + goto err_checkrange; > > + } > > + > > No need to check under the memory hotplug lock. > Thanks, I'll adjust it. > > /* > > * For device private memory we call add_pages() as we only need to > > * allocate and initialize struct page for the device memory. More- > > @@ -324,6 +331,7 @@ void *devm_memremap_pages(struct device *dev, > > struct dev_pagemap *pgmap) > > > > err_add_memory: > > kasan_remove_zero_shadow(__va(res->start), resource_size(res)); > > + err_checkrange: > > err_kasan: > > untrack_pfn(NULL, PHYS_PFN(res->start), resource_size(res)); > > err_pfn_remap: > > > > > -- > > Thanks, > > David / dhildenb >
diff --git a/mm/memremap.c b/mm/memremap.c index 86432650f829..fd00993caa3e 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -269,6 +269,13 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) mem_hotplug_begin(); + error = check_hotplug_memory_addressable(res->start, + resource_size(res)); + if (error) { + mem_hotplug_done(); + goto err_checkrange; + } + /* * For device private memory we call add_pages() as we only need to * allocate and initialize struct page for the device memory. More- @@ -324,6 +331,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) err_add_memory: kasan_remove_zero_shadow(__va(res->start), resource_size(res)); + err_checkrange: err_kasan: untrack_pfn(NULL, PHYS_PFN(res->start), resource_size(res)); err_pfn_remap: