Lorenzo Stoakes 38e0885465 mm: check VMA flags to avoid invalid PROT_NONE NUMA balancing ... The NUMA balancing logic uses an arch-specific PROT_NONE page table flag defined by pte_protnone() or pmd_protnone() to mark PTEs or huge page PMDs respectively as requiring balancing upon a subsequent page fault. User-defined PROT_NONE memory regions which also have this flag set will not normally invoke the NUMA balancing code as do_page_fault() will send a segfault to the process before handle_mm_fault() is even called. However if access_remote_vm() is invoked to access a PROT_NONE region of memory, handle_mm_fault() is called via faultin_page() and __get_user_pages() without any access checks being performed, meaning the NUMA balancing logic is incorrectly invoked on a non-NUMA memory region. A simple means of triggering this problem is to access PROT_NONE mmap'd memory using /proc/self/mem which reliably results in the NUMA handling functions being invoked when CONFIG_NUMA_BALANCING is set. This issue was reported in bugzilla (issue 99101) which includes some simple repro code. There are BUG_ON() checks in do_numa_page() and do_huge_pmd_numa_page() added at commit c0e7cad to avoid accidentally provoking strange behaviour by attempting to apply NUMA balancing to pages that are in fact PROT_NONE. The BUG_ON()'s are consistently triggered by the repro. This patch moves the PROT_NONE check into mm/memory.c rather than invoking BUG_ON() as faulting in these pages via faultin_page() is a valid reason for reaching the NUMA check with the PROT_NONE page table flag set and is therefore not always a bug. Link: https://bugzilla.kernel.org/show_bug.cgi?id=99101 Reported-by: Trevor Saunders <tbsaunde@tbsaunde.org> Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2016-09-25 15:43:42 -07:00
..
kasan
backing-dev.c
balloon_compaction.c
bootmem.c
cleancache.c
cma.c
cma.h
cma_debug.c
compaction.c
debug.c	mm: avoid endless recursion in dump_page()	2016-09-19 15:36:16 -07:00
debug_page_ref.c
dmapool.c
early_ioremap.c
fadvise.c
failslab.c
filemap.c
frame_vector.c
frontswap.c
gup.c
highmem.c
huge_memory.c	mm: check VMA flags to avoid invalid PROT_NONE NUMA balancing	2016-09-25 15:43:42 -07:00
hugetlb.c
hugetlb_cgroup.c
hwpoison-inject.c
init-mm.c
internal.h
interval_tree.c
Kconfig
Kconfig.debug
khugepaged.c	mm, thp: fix leaking mapped pte in __collapse_huge_page_swapin()	2016-09-19 15:36:16 -07:00
kmemcheck.c
kmemleak-test.c
kmemleak.c
ksm.c
list_lru.c
maccess.c
madvise.c
Makefile
memblock.c
memcontrol.c	mm: memcontrol: make per-cpu charge cache IRQ-safe for socket accounting	2016-09-19 15:36:17 -07:00
memory-failure.c
memory.c	mm: check VMA flags to avoid invalid PROT_NONE NUMA balancing	2016-09-25 15:43:42 -07:00
memory_hotplug.c	mem-hotplug: don't clear the only node in new_node_page()	2016-09-19 15:36:16 -07:00
mempolicy.c
mempool.c
memtest.c
migrate.c
mincore.c
mlock.c
mm_init.c
mmap.c
mmu_context.c
mmu_notifier.c
mmzone.c
mprotect.c
mremap.c
msync.c
nobootmem.c
nommu.c
oom_kill.c
page-writeback.c
page_alloc.c
page_counter.c
page_ext.c
page_idle.c
page_io.c	mm: fix the page_swap_info() BUG_ON check	2016-09-19 15:36:17 -07:00
page_isolation.c
page_owner.c
page_poison.c
pagewalk.c
percpu-km.c
percpu-vm.c
percpu.c
pgtable-generic.c
process_vm_access.c
quicklist.c
readahead.c
rmap.c
shmem.c	huge tmpfs: fix Committed_AS leak	2016-09-24 11:20:01 -07:00
slab.c
slab.h
slab_common.c
slob.c
slub.c
sparse-vmemmap.c
sparse.c
swap.c
swap_cgroup.c
swap_state.c
swapfile.c	mm: fix the page_swap_info() BUG_ON check	2016-09-19 15:36:17 -07:00
truncate.c
usercopy.c	mm: usercopy: Check for module addresses	2016-09-20 16:07:39 -07:00
userfaultfd.c
util.c
vmacache.c
vmalloc.c
vmpressure.c
vmscan.c	mm: delete unnecessary and unsafe init_tlb_ubc()	2016-09-24 11:20:01 -07:00
vmstat.c
workingset.c
z3fold.c
zbud.c
zpool.c
zsmalloc.c
zswap.c