Ard Biesheuvel 647f605276 mm/vmalloc.c: huge-vmap: fail gracefully on unexpected huge vmap mappings ... commit 029c54b095 upstream. Existing code that uses vmalloc_to_page() may assume that any address for which is_vmalloc_addr() returns true may be passed into vmalloc_to_page() to retrieve the associated struct page. This is not un unreasonable assumption to make, but on architectures that have CONFIG_HAVE_ARCH_HUGE_VMAP=y, it no longer holds, and we need to ensure that vmalloc_to_page() does not go off into the weeds trying to dereference huge PUDs or PMDs as table entries. Given that vmalloc() and vmap() themselves never create huge mappings or deal with compound pages at all, there is no correct answer in this case, so return NULL instead, and issue a warning. When reading /proc/kcore on arm64, you will hit an oops as soon as you hit the huge mappings used for the various segments that make up the mapping of vmlinux. With this patch applied, you will no longer hit the oops, but the kcore contents willl be incorrect (these regions will be zeroed out) We are fixing this for kcore specifically, so it avoids vread() for those regions. At least one other problematic user exists, i.e., /dev/kmem, but that is currently broken on arm64 for other reasons. Link: http://lkml.kernel.org/r/20170609082226.26152-1-ard.biesheuvel@linaro.org Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Laura Abbott <labbott@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: zhong jiang <zhongjiang@huawei.com> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [ardb: non-trivial backport to v4.9] Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2017-07-05 14:40:28 +02:00
..
kasan	kasan: respect /proc/sys/kernel/traceoff_on_warning	2017-06-17 06:41:51 +02:00
backing-dev.c	block: fix double-free in the failure path of cgwb_bdi_init()	2017-02-26 11:10:52 +01:00
balloon_compaction.c	mm: balloon: use general non-lru movable page feature	2016-07-26 16:19:19 -07:00
bootmem.c	mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping	2016-10-11 15:06:33 -07:00
cleancache.c	cleancache: constify cleancache_ops structure	2016-01-27 09:09:57 -05:00
cma.c	mm/cma.c: check the max limit for cma allocation	2016-11-11 08:12:37 -08:00
cma.h	mm: cma: mark cma_bitmap_maxno() inline in header	2015-08-14 15:56:32 -07:00
cma_debug.c	mm/cma_debug: correct size input to bitmap function	2015-07-17 16:39:54 -07:00
compaction.c	mm, compaction: fix NR_ISOLATED_* stats for pfn based migration	2017-01-12 11:39:32 +01:00
debug.c	mm: clarify why we avoid page_mapcount() for slab pages in dump_page()	2016-10-07 18:46:29 -07:00
debug_page_ref.c	mm/page_ref: add tracepoint to track down page reference manipulation	2016-03-17 15:09:34 -07:00
dmapool.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
early_ioremap.c	mm/early_ioremap: use offset_in_page macro	2015-11-05 19:34:48 -08:00
fadvise.c	mm/fadvise.c: do not discard partial pages with POSIX_FADV_DONTNEED	2016-06-09 14:23:11 -07:00
failslab.c	mm: fault-inject take over bootstrap kmem_cache check	2016-03-15 16:55:16 -07:00
filemap.c	mm: do not access page->mapping directly on page_endio	2017-03-12 06:41:43 +01:00
frame_vector.c	mm: replace get_vaddr_frames() write/force parameters with gup_flags	2016-10-19 08:11:24 -07:00
frontswap.c	mm, frontswap: convert frontswap_enabled to static key	2016-07-26 16:19:19 -07:00
gup.c	mm: larger stack guard gap, between vmas	2017-06-24 07:11:18 +02:00
highmem.c	mm/highmem: make nr_free_highpages() handles all highmem zones by itself	2016-05-19 19:12:14 -07:00
huge_memory.c	mm: numa: avoid waiting on freed migrated pages	2017-07-05 14:40:19 +02:00
hugetlb.c	mm, hugetlb: use pte_present() instead of pmd_present() in follow_huge_pmd()	2017-04-08 09:30:35 +02:00
hugetlb_cgroup.c	mm, hugetlb_cgroup: round limit_in_bytes down to hugepage size	2016-05-20 17:58:30 -07:00
hwpoison-inject.c	hwpoison: use page_cgroup_ino for filtering by memcg	2015-09-10 13:29:01 -07:00
init-mm.c	mm: Add a user_ns owner to mm_struct and fix ptrace permission checks	2017-01-06 10:40:13 +01:00
internal.h	mm, compaction: make full priority ignore pageblock suitability	2016-10-07 18:46:29 -07:00
interval_tree.c	mm: replace vma->sharead.linear with vma->shared	2015-02-10 14:30:31 -08:00
Kconfig	Allow KASAN and HOTPLUG_MEMORY to co-exist when doing build testing	2016-10-27 16:23:01 -07:00
Kconfig.debug	PM / Hibernate: allow hibernation with PAGE_POISONING_ZERO	2016-09-13 02:35:27 +02:00
khugepaged.c	mm: khugepaged: fix radix tree node leak in shmem collapse error path	2017-01-12 11:39:32 +01:00
kmemcheck.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
kmemleak-test.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
kmemleak.c	mm: kmemleak: scan .data.ro_after_init	2016-11-11 08:12:37 -08:00
ksm.c	ksm: prevent crash after write_protect_page fails	2017-06-07 12:07:49 +02:00
list_lru.c	mm/list_lru.c: avoid error-path NULL pointer deref	2016-10-27 18:43:42 -07:00
maccess.c	x86: remove more uaccess_32.h complexity	2016-05-22 17:21:27 -07:00
madvise.c	mm: make mmap_sem for write waits killable for mm syscalls	2016-05-23 17:04:14 -07:00
Makefile	Disable the __builtin_return_address() warning globally after all	2016-10-12 10:23:41 -07:00
memblock.c	mm: consider memblock reservations for deferred memory initialization sizing	2017-06-07 12:07:49 +02:00
memcontrol.c	mm: memcontrol: use special workqueue for creating per-memcg caches	2017-04-21 09:31:23 +02:00
memory-failure.c	mm/memory-failure.c: use compound_head() flags for huge pages	2017-06-24 07:11:16 +02:00
memory.c	mm: larger stack guard gap, between vmas	2017-06-24 07:11:18 +02:00
memory_hotplug.c	base/memory, hotplug: fix a kernel oops in show_valid_zones()	2017-02-09 08:08:28 +01:00
mempolicy.c	mm/mempolicy.c: fix error handling in set_mempolicy and mbind.	2017-04-12 12:41:15 +02:00
mempool.c	Revert "mm, mempool: only set __GFP_NOMEMALLOC if there are free elements"	2016-07-28 16:07:41 -07:00
memtest.c	memtest: remove unused header files	2015-09-08 15:35:28 -07:00
migrate.c	mm: prevent NR_ISOLATE_* stats from going negative	2017-04-27 09:10:37 +02:00
mincore.c	mm, swap: use offset of swap entry as key of swap cache	2016-10-07 18:46:28 -07:00
mlock.c	mlock: fix mlock count can not decrease in race condition	2017-06-07 12:07:49 +02:00
mm_init.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
mmap.c	mm: fix new crash in unmapped_area_topdown()	2017-06-24 07:11:18 +02:00
mmu_context.c	mm/mmu_context, sched/core: Fix mmu_context.h assumption	2016-04-28 11:44:19 +02:00
mmu_notifier.c	fix Christoph's email addresses	2016-03-17 15:09:34 -07:00
mmzone.c	mm, page_alloc: inline the fast path of the zonelist iterator	2016-05-19 19:12:14 -07:00
mprotect.c	mm/numa: Remove duplicated include from mprotect.c	2016-10-19 17:28:48 +02:00
mremap.c	mremap: move_ptes: check pte dirty after its removal	2016-11-29 08:20:24 -08:00
msync.c	mm/msync: use offset_in_page macro	2015-11-05 19:34:48 -08:00
nobootmem.c	mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping	2016-10-11 15:06:33 -07:00
nommu.c	ptrace: Don't allow accessing an undumpable mm	2017-01-06 10:40:13 +01:00
oom_kill.c	oom: print nodemask in the oom report	2016-10-07 18:46:29 -07:00
page-writeback.c	mm: don't use radix tree writeback tags for pages in swap cache	2016-10-07 18:46:28 -07:00
page_alloc.c	mm: consider memblock reservations for deferred memory initialization sizing	2017-06-07 12:07:49 +02:00
page_counter.c	mm: page_counter: let page_counter_try_charge() return bool	2015-11-05 19:34:48 -08:00
page_ext.c	mm/page_ext: support extra space allocation by page_ext user	2016-10-07 18:46:27 -07:00
page_idle.c	mm, vmscan: move lru_lock to the node	2016-07-28 16:07:41 -07:00
page_io.c	mm/page_io.c: replace some BUG_ON()s with VM_BUG_ON_PAGE()	2016-10-07 18:46:29 -07:00
page_isolation.c	mm/page_isolation: fix typo: "paes" -> "pages"	2016-10-07 18:46:29 -07:00
page_owner.c	mm/page_owner: don't define fields on struct page_ext by hard-coding	2016-10-07 18:46:27 -07:00
page_poison.c	mm: check the return value of lookup_page_ext for all call sites	2016-06-03 15:06:22 -07:00
pagewalk.c	thp: rename split_huge_page_pmd() to split_huge_pmd()	2016-01-15 17:56:32 -08:00
percpu-km.c	mm: percpu: use pr_fmt to prefix output	2016-03-17 15:09:34 -07:00
percpu-vm.c	percpu: move region iterations out of pcpu_[de]populate_chunk()	2014-09-02 14:46:02 -04:00
percpu.c	percpu: acquire pcpu_lock when updating pcpu_nr_empty_pop_pages	2017-03-26 13:05:58 +02:00
pgtable-generic.c	mm/thp/migration: switch from flush_tlb_range to flush_pmd_tlb_range	2016-03-17 15:09:34 -07:00
process_vm_access.c	mm: remove write/force parameters from __get_user_pages_unlocked()	2016-10-18 14:13:37 -07:00
quicklist.c	fix Christoph's email addresses	2016-03-17 15:09:34 -07:00
readahead.c	mm: silently skip readahead for DAX inodes	2016-08-26 17:39:35 -07:00
rmap.c	mm: rmap: fix huge file mmap accounting in the memcg stats	2017-04-08 09:30:35 +02:00
shmem.c	shmem: fix sleeping from atomic context	2017-06-17 06:41:51 +02:00
slab.c	slub: move synchronize_sched out of slab_mutex on shrink	2017-03-22 12:43:38 +01:00
slab.h	slub: move synchronize_sched out of slab_mutex on shrink	2017-03-22 12:43:38 +01:00
slab_common.c	slub: move synchronize_sched out of slab_mutex on shrink	2017-03-22 12:43:38 +01:00
slob.c	slub: move synchronize_sched out of slab_mutex on shrink	2017-03-22 12:43:38 +01:00
slub.c	mm/slub.c: trace free objects at KERN_INFO	2017-06-07 12:07:49 +02:00
sparse-vmemmap.c	treewide: replace obsolete _refok by __ref	2016-08-02 17:31:41 -04:00
sparse.c	treewide: replace obsolete _refok by __ref	2016-08-02 17:31:41 -04:00
swap.c	thp: reduce usage of huge zero page's atomic counter	2016-10-07 18:46:28 -07:00
swap_cgroup.c	mm, swap_cgroup: reschedule when neeed in swap_cgroup_swapoff()	2017-07-05 14:40:17 +02:00
swap_state.c	mm, swap: use offset of swap entry as key of swap cache	2016-10-07 18:46:28 -07:00
swapfile.c	mm: support anonymous stable page	2017-01-19 20:17:59 +01:00
truncate.c	fs: add i_blocksize()	2017-06-14 15:06:00 +02:00
usercopy.c	mm: usercopy: Check for module addresses	2016-09-20 16:07:39 -07:00
userfaultfd.c	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00
util.c	Merge branch 'mm-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-10-22 09:39:10 -07:00
vmacache.c	mm: unrig VMA cache hit ratio	2016-10-07 18:46:27 -07:00
vmalloc.c	mm/vmalloc.c: huge-vmap: fail gracefully on unexpected huge vmap mappings	2017-07-05 14:40:28 +02:00
vmpressure.c	mm: vmpressure: fix sending wrong events on underflow	2017-03-12 06:41:43 +01:00
vmscan.c	mm, vmscan: consider eligible zones in get_scan_count	2017-03-12 06:41:44 +01:00
vmstat.c	seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not char	2016-10-07 18:46:30 -07:00
workingset.c	mm: workingset: fix premature shadow node shrinking with cgroups	2017-04-08 09:30:36 +02:00
z3fold.c	mm/z3fold.c: avoid modifying HEADLESS page and minor cleanup	2016-06-03 16:02:55 -07:00
zbud.c	mm/zbud.c: use list_last_entry() instead of list_tail_entry()	2016-01-15 11:40:52 -08:00
zpool.c	mm: zsmalloc: constify struct zs_pool name	2015-11-06 17:50:42 -08:00
zsmalloc.c	zsmalloc: expand class bit	2017-04-21 09:31:19 +02:00
zswap.c	zswap: disable changing params if init fails	2017-02-09 08:08:27 +01:00