linux/mm
Vlastimil Babka 9050d7eba4 mm: include VM_MIXEDMAP flag in the VM_SPECIAL list to avoid m(un)locking
Daniel Borkmann reported a VM_BUG_ON assertion failing:

  ------------[ cut here ]------------
  kernel BUG at mm/mlock.c:528!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: ccm arc4 iwldvm [...]
   video
  CPU: 3 PID: 2266 Comm: netsniff-ng Not tainted 3.14.0-rc2+ #8
  Hardware name: LENOVO 2429BP3/2429BP3, BIOS G4ET37WW (1.12 ) 05/29/2012
  task: ffff8801f87f9820 ti: ffff88002cb44000 task.ti: ffff88002cb44000
  RIP: 0010:[<ffffffff81171ad0>]  [<ffffffff81171ad0>] munlock_vma_pages_range+0x2e0/0x2f0
  Call Trace:
    do_munmap+0x18f/0x3b0
    vm_munmap+0x41/0x60
    SyS_munmap+0x22/0x30
    system_call_fastpath+0x1a/0x1f
  RIP   munlock_vma_pages_range+0x2e0/0x2f0
  ---[ end trace a0088dcf07ae10f2 ]---

because munlock_vma_pages_range() thinks it's unexpectedly in the middle
of a THP page.  This can be reproduced with default config since 3.11
kernels.  A reproducer can be found in the kernel's selftest directory
for networking by running ./psock_tpacket.

The problem is that an order=2 compound page (allocated by
alloc_one_pg_vec_page() is part of the munlocked VM_MIXEDMAP vma (mapped
by packet_mmap()) and mistaken for a THP page and assumed to be order=9.

The checks for THP in munlock came with commit ff6a6da60b ("mm:
accelerate munlock() treatment of THP pages"), i.e.  since 3.9, but did
not trigger a bug.  It just makes munlock_vma_pages_range() skip such
compound pages until the next 512-pages-aligned page, when it encounters
a head page.  This is however not a problem for vma's where mlocking has
no effect anyway, but it can distort the accounting.

Since commit 7225522bb4 ("mm: munlock: batch non-THP page isolation
and munlock+putback using pagevec") this can trigger a VM_BUG_ON in
PageTransHuge() check.

This patch fixes the issue by adding VM_MIXEDMAP flag to VM_SPECIAL, a
list of flags that make vma's non-mlockable and non-mergeable.  The
reasoning is that VM_MIXEDMAP vma's are similar to VM_PFNMAP, which is
already on the VM_SPECIAL list, and both are intended for non-LRU pages
where mlocking makes no sense anyway.  Related Lkml discussion can be
found in [2].

 [1] tools/testing/selftests/net/psock_tpacket
 [2] https://lkml.org/lkml/2014/1/10/427

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Reported-by: Daniel Borkmann <dborkman@redhat.com>
Tested-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: John David Anglin <dave.anglin@bell.net>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Jared Hulbert <jaredeh@gmail.com>
Tested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org> [3.11.x+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-03-04 07:55:48 -08:00
..
backing-dev.c mm/backing-dev.c: check user buffer length before copying data to the related user buffer 2013-09-11 15:58:03 -07:00
balloon_compaction.c mm: print more details for bad_page() 2014-01-23 16:36:50 -08:00
bootmem.c mm/bootmem.c: remove unused local `map' 2013-11-13 12:09:09 +09:00
bounce.c block: Convert bio_for_each_segment() to bvec_iter 2013-11-23 22:33:49 -08:00
cleancache.c mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGE 2014-01-23 16:36:50 -08:00
compaction.c mm: improve documentation of page_order 2014-01-23 16:36:53 -08:00
debug-pagealloc.c
dmapool.c dmapool: make DMAPOOL_DEBUG detect corruption of free marker 2012-12-11 17:22:24 -08:00
fadvise.c teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long long 2013-03-03 22:46:22 -05:00
failslab.c
filemap_xip.c seqcount: Add lockdep functionality to seqcount/seqlock structures 2013-11-06 12:40:26 +01:00
filemap.c fix O_SYNC|O_APPEND syncing the wrong range on write() 2014-02-09 15:18:09 -05:00
fremap.c mm: fix use-after-free in sys_remap_file_pages 2014-01-02 14:40:30 -08:00
frontswap.c frontswap: fix incorrect zeroing and allocation size for frontswap_map 2013-06-12 16:29:46 -07:00
highmem.c Some nice cleanups, and even a patch my wife did as a "live" demo for 2012-12-20 08:37:05 -08:00
huge_memory.c mm: include VM_MIXEDMAP flag in the VM_SPECIAL list to avoid m(un)locking 2014-03-04 07:55:48 -08:00
hugetlb_cgroup.c mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGE 2014-01-23 16:36:50 -08:00
hugetlb.c mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGE 2014-01-23 16:36:50 -08:00
hwpoison-inject.c mm/hwpoison: add '#' to hwpoison_inject 2014-01-21 16:19:48 -08:00
init-mm.c
internal.h mm/page-writeback.c: do not count anon pages as dirtyable memory 2014-01-29 16:22:39 -08:00
interval_tree.c mm: add CONFIG_DEBUG_VM_RB build option 2012-10-09 16:22:42 +09:00
Kconfig zsmalloc: move it under mm 2014-01-30 16:56:55 -08:00
Kconfig.debug
kmemcheck.c
kmemleak-test.c
kmemleak.c mm: kmemleak: avoid false negatives on vmalloc'ed objects 2013-11-13 12:09:07 +09:00
ksm.c mm: close PageTail race 2014-03-04 07:55:47 -08:00
list_lru.c mm: list_lru: fix almost infinite loop causing effective livelock 2013-10-30 12:57:46 -07:00
maccess.c
madvise.c mm/hwpoison: fix traversal of hugetlbfs pages to avoid printk flood 2013-09-30 14:31:02 -07:00
Makefile zsmalloc: move it under mm 2014-01-30 16:56:55 -08:00
memblock.c memblock: add limit checking to memblock_virt_alloc 2014-01-29 16:22:40 -08:00
memcontrol.c memcg: reparent charges of children before processing parent 2014-03-04 07:55:48 -08:00
memory_hotplug.c mm/memory_hotplug.c: move register_memory_resource out of the lock_memory_hotplug 2014-01-23 16:36:52 -08:00
memory-failure.c mm: close PageTail race 2014-03-04 07:55:47 -08:00
memory.c mm, thp: fix infinite loop on memcg OOM 2014-02-25 15:25:44 -08:00
mempolicy.c mm/mempolicy.c: fix mempolicy printing in numa_maps 2014-01-30 16:56:56 -08:00
mempool.c mm/mempool.c: convert kmalloc_node(...GFP_ZERO...) to kzalloc_node(...) 2013-09-11 15:58:14 -07:00
migrate.c mm/migrate.c: fix setting of cpupid on page migration twice against normal page 2014-01-27 21:02:40 -08:00
mincore.c mm: do_mincore() cleanup 2014-01-23 16:36:52 -08:00
mlock.c mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGE 2014-01-23 16:36:50 -08:00
mm_init.c mm: bring back /sys/kernel/mm 2014-01-27 21:02:39 -08:00
mmap.c mm: ignore VM_SOFTDIRTY on VMA merging 2014-01-23 16:36:53 -08:00
mmu_context.c mm: remove old aio use_mm() comment 2013-05-07 18:38:27 -07:00
mmu_notifier.c mm: audit/fix non-modular users of module_init in core code 2014-01-23 16:36:52 -08:00
mmzone.c mm: numa: Change page last {nid,pid} into {cpu,pid} 2013-10-09 14:47:45 +02:00
mprotect.c mm: Use ptep/pmdp_set_numa() for updating _PAGE_NUMA bit 2014-02-17 11:19:36 +11:00
mremap.c mm: revert mremap pud_free anti-fix 2013-10-16 21:35:53 -07:00
msync.c
nobootmem.c mm/nobootmem: free_all_bootmem again 2014-01-23 16:36:52 -08:00
nommu.c mm: add overcommit_kbytes sysctl variable 2014-01-21 16:19:44 -08:00
oom_kill.c mm, oom: base root bonus on current usage 2014-01-30 16:56:56 -08:00
page_alloc.c mm: close PageTail race 2014-03-04 07:55:47 -08:00
page_cgroup.c Merge branch 'akpm' (incoming from Andrew) 2014-01-21 19:05:45 -08:00
page_io.c Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
page_isolation.c mm: memory-hotplug: enable memory hotplug to handle hugepage 2013-09-11 15:57:48 -07:00
page-writeback.c mm: __set_page_dirty_nobuffers() uses spin_lock_irqsave() instead of spin_lock_irq() 2014-02-06 13:48:51 -08:00
pagewalk.c mm/pagewalk.c: fix walk_page_range() access of wrong PTEs 2013-10-30 14:27:03 -07:00
percpu-km.c
percpu-vm.c mm: fix kernel-doc warnings 2012-06-20 14:39:36 -07:00
percpu.c Merge branch 'akpm' (incoming from Andrew) 2014-01-21 19:05:45 -08:00
pgtable-generic.c mm: fix TLB flush race between migration, and change_protection_range 2013-12-18 19:04:51 -08:00
process_vm_access.c Fix: compat_rw_copy_check_uvector() misuse in aio, readv, writev, and security keys 2013-03-12 11:05:45 -07:00
quicklist.c
readahead.c mm/readahead.c: fix do_readahead() for no readpage(s) 2014-01-29 16:22:40 -08:00
rmap.c mm/rmap: fix coccinelle warnings 2014-01-23 16:36:53 -08:00
shmem.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-01-28 08:38:04 -08:00
slab_common.c slab: fix wrong retval on kmem_cache_create_memcg error path 2014-01-29 16:22:40 -08:00
slab.c mm: Fix warning on make htmldocs caused by slab.c 2014-01-31 13:52:25 +02:00
slab.h memcg, slab: RCU protect memcg_params for root caches 2014-01-23 16:36:51 -08:00
slob.c mm/sl[aou]b: Move kmallocXXX functions to common code 2013-09-04 20:51:33 +03:00
slub.c slub: do not assert not having lock in removing freed partial 2014-02-10 16:01:42 -08:00
sparse-vmemmap.c mm/sparse: use memblock apis for early memory allocations 2014-01-21 16:19:47 -08:00
sparse.c mm/sparse: use memblock apis for early memory allocations 2014-01-21 16:19:47 -08:00
swap_state.c swap: add a simple detector for inappropriate swapin readahead 2014-02-06 13:48:51 -08:00
swap.c mm: close PageTail race 2014-03-04 07:55:47 -08:00
swapfile.c mm/swap: fix race on swap_info reuse between swapoff and swapon 2014-02-06 13:48:51 -08:00
truncate.c truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
util.c mm: add overcommit_kbytes sysctl variable 2014-01-21 16:19:44 -08:00
vmalloc.c Revert "mm/vmalloc: interchage the implementation of vmalloc_to_{pfn,page}" 2014-01-27 21:02:39 -08:00
vmpressure.c arm, pm, vmpressure: add missing slab.h includes 2014-02-03 13:24:01 -05:00
vmscan.c mm/page-writeback.c: do not count anon pages as dirtyable memory 2014-01-29 16:22:39 -08:00
vmstat.c mm, x86: Account for TLB flushes only when debugging 2014-01-25 09:10:41 +01:00
zbud.c mm/zbud: fix some trivial typos in comments 2013-09-11 15:57:35 -07:00
zsmalloc.c zsmalloc: add copyright 2014-01-30 16:56:55 -08:00
zswap.c mm/zswap.c: change params from hidden to ro 2014-01-23 16:36:50 -08:00