alistair23-linux/mm
Huang Ying aeb309b81c mm/mincore.c: fix race between swapoff and mincore
Via commit 4b3ef9daa4 ("mm/swap: split swap cache into 64MB trunks"),
after swapoff, the address_space associated with the swap device will be
freed.  So swap_address_space() users which touch the address_space need
some kind of mechanism to prevent the address_space from being freed
during accessing.

When mincore processes an unmapped range for swapped shmem pages, it
doesn't hold the lock to prevent swap device from being swapped off.  So
the following race is possible:

CPU1					CPU2
do_mincore()				swapoff()
  walk_page_range()
    mincore_unmapped_range()
      __mincore_unmapped_range
        mincore_page
	  as = swap_address_space()
          ...				  exit_swap_address_space()
          ...				    kvfree(spaces)
	  find_get_page(as)

The address space may be accessed after being freed.

To fix the race, get_swap_device()/put_swap_device() is used to enclose
find_get_page() to check whether the swap entry is valid and prevent the
swap device from being swapoff during accessing.

Link: http://lkml.kernel.org/r/20190611020510.28251-1-ying.huang@intel.com
Fixes: 4b3ef9daa4 ("mm/swap: split swap cache into 64MB trunks")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Andrea Parri <andrea.parri@amarulasolutions.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-12 11:05:43 -07:00
..
kasan mm/kasan: change kasan_check_{read,write} to return boolean 2019-07-12 11:05:42 -07:00
backing-dev.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
balloon_compaction.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
cleancache.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482 2019-06-19 17:09:52 +02:00
cma.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 98 2019-05-24 17:37:54 +02:00
cma.h
cma_debug.c mm/cma_debug.c: fix the break condition in cma_maxchunk_get() 2019-05-14 09:47:45 -07:00
compaction.c mm, compaction: make sure we isolate a valid PFN 2019-06-01 15:51:32 -07:00
debug.c mm: update references to page _refcount 2019-05-14 19:52:47 -07:00
debug_page_ref.c
dmapool.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 403 2019-06-05 17:37:13 +02:00
early_ioremap.c
fadvise.c
failslab.c mm/failslab.c: by default, do not fail allocations with direct reclaim only 2019-07-12 11:05:43 -07:00
filemap.c mm/filemap.c: correct the comment about VM_FAULT_RETRY 2019-07-12 11:05:43 -07:00
frame_vector.c
frontswap.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482 2019-06-19 17:09:52 +02:00
gup.c mm/gup.c: make follow_page_mask() static 2019-07-12 11:05:42 -07:00
gup_benchmark.c mm/gup: replace get_user_pages_longterm() with FOLL_LONGTERM 2019-05-14 09:47:45 -07:00
highmem.c
hmm.c mm/devm_memremap_pages: fix final page put race 2019-06-13 17:34:56 -10:00
huge_memory.c Revert "mm: page cache: store only head pages in i_pages" 2019-07-05 19:55:18 -07:00
hugetlb.c mm: hugetlb: soft-offline: dissolve_free_huge_page() return zero on !PageHuge 2019-06-29 16:43:45 +08:00
hugetlb_cgroup.c
hwpoison-inject.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
init-mm.c
internal.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
interval_tree.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 248 2019-06-19 17:09:08 +02:00
Kconfig Linux 5.2-rc4 2019-06-14 14:18:53 -06:00
Kconfig.debug mm, debug_pagealloc: use a page type instead of page_ext flag 2019-07-12 11:05:43 -07:00
khugepaged.c Revert "mm: page cache: store only head pages in i_pages" 2019-07-05 19:55:18 -07:00
kmemleak-test.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
kmemleak.c mm/kmemleak.c: change error at _write when kmemleak is disabled 2019-07-12 11:05:42 -07:00
ksm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482 2019-06-19 17:09:52 +02:00
list_lru.c mm/list_lru.c: fix memory leak in __memcg_init_list_lru_node 2019-06-13 17:34:56 -10:00
maccess.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
madvise.c mm/mmu_notifier: use correct mmu_notifier events for each invalidation 2019-05-14 09:47:49 -07:00
Makefile mm: shuffle initial free memory to improve memory-side-cache utilization 2019-05-14 19:52:48 -07:00
memblock.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
memcontrol.c mm/memcontrol: fix wrong statistics in memory.stat 2019-07-12 11:05:40 -07:00
memfd.c Revert "mm: page cache: store only head pages in i_pages" 2019-07-05 19:55:18 -07:00
memory-failure.c Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2019-07-08 21:48:15 -07:00
memory.c mm, swap: fix race between swapoff and some swap operations 2019-07-12 11:05:43 -07:00
memory_hotplug.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
mempolicy.c mm/mempolicy.c: fix an incorrect rebind node in mpol_rebind_nodemask 2019-06-29 16:43:44 +08:00
mempool.c docs/core-api/mm: fix return value descriptions in mm/ 2019-03-05 21:07:20 -08:00
memtest.c
migrate.c Revert "mm: page cache: store only head pages in i_pages" 2019-07-05 19:55:18 -07:00
mincore.c mm/mincore.c: fix race between swapoff and mincore 2019-07-12 11:05:43 -07:00
mlock.c mm/mlock.c: change count_mm_mlocked_page_nr return type 2019-06-13 17:34:56 -10:00
mm_init.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
mmap.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
mmu_context.c
mmu_gather.c mm: mmu_gather: remove __tlb_reset_range() for force flush 2019-06-13 17:34:56 -10:00
mmu_notifier.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499 2019-06-19 17:09:53 +02:00
mmzone.c
mprotect.c mm/mprotect.c: fix compilation warning because of unused 'mm' variable 2019-05-14 09:47:51 -07:00
mremap.c mm/mmu_notifier: contextual information for event triggering invalidation 2019-05-14 09:47:49 -07:00
msync.c
nommu.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
oom_kill.c mm/oom_kill.c: fix uninitialized oc->constraint 2019-06-29 16:43:45 +08:00
page-writeback.c mm: remove the account_page_dirtied export 2019-07-12 11:05:42 -07:00
page_alloc.c mm, debug_pagealloc: use a page type instead of page_ext flag 2019-07-12 11:05:43 -07:00
page_counter.c
page_ext.c mm, debug_pagealloc: use a page type instead of page_ext flag 2019-07-12 11:05:43 -07:00
page_idle.c mm/page_idle.c: fix oops because end_pfn is larger than max_pfn 2019-06-29 16:43:45 +08:00
page_io.c mm, swap: use rbtree for swap_extent 2019-07-12 11:05:43 -07:00
page_isolation.c mm/page_isolation.c: change the prototype of undo_isolate_page_range() 2019-07-12 11:05:43 -07:00
page_owner.c mm/page_owner: Simplify stack trace handling 2019-04-29 12:37:50 +02:00
page_poison.c page_poison: play nicely with KASAN 2019-03-05 21:07:13 -08:00
page_vma_mapped.c
pagewalk.c
percpu-internal.h percpu: convert chunk hints to be based on pcpu_block_md 2019-03-13 12:25:31 -07:00
percpu-km.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
percpu-stats.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
percpu-vm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
percpu.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
pgtable-generic.c
process_vm_access.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
quicklist.c
readahead.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
rmap.c mm/rmap.c: use the pra.mapcount to do the check 2019-05-14 09:47:49 -07:00
rodata_test.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
shmem.c Revert "mm: page cache: store only head pages in i_pages" 2019-07-05 19:55:18 -07:00
shuffle.c mm: maintain randomization of page free lists 2019-05-14 19:52:48 -07:00
shuffle.h mm: maintain randomization of page free lists 2019-05-14 19:52:48 -07:00
slab.c mm/slab: refactor common ksize KASAN logic into slab_common.c 2019-07-12 11:05:42 -07:00
slab.h mm/slab: sanity-check page type when looking up cache 2019-07-12 11:05:41 -07:00
slab_common.c mm/kasan: add object validation in ksize() 2019-07-12 11:05:42 -07:00
slob.c mm/slab: refactor common ksize KASAN logic into slab_common.c 2019-07-12 11:05:42 -07:00
slub.c mm/slab: refactor common ksize KASAN logic into slab_common.c 2019-07-12 11:05:42 -07:00
sparse-vmemmap.c
sparse.c mm/sparse.c: clean up obsolete code comment 2019-05-14 09:47:48 -07:00
swap.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
swap_cgroup.c
swap_slots.c
swap_state.c mm/swap_state.c: simplify total_swapcache_pages() with get_swap_device() 2019-07-12 11:05:43 -07:00
swapfile.c mm, swap: use rbtree for swap_extent 2019-07-12 11:05:43 -07:00
truncate.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
usercopy.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
userfaultfd.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499 2019-06-19 17:09:53 +02:00
util.c prctl_set_mm: downgrade mmap_sem to read lock 2019-06-01 15:51:31 -07:00
vmacache.c
vmalloc.c arm64 updates for 5.3: 2019-07-08 09:54:55 -07:00
vmpressure.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
vmscan.c mm: vmscan: scan anonymous pages on file refaults 2019-07-12 11:05:39 -07:00
vmstat.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
workingset.c mm: memcontrol: make cgroup stats and events query API explicitly local 2019-05-14 19:52:53 -07:00
z3fold.c mm/z3fold.c: lock z3fold page before __SetPageMovable() 2019-07-12 11:05:40 -07:00
zbud.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
zpool.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
zsmalloc.c
zswap.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00