linux/mm
Andrey Vagin 6f6b895189 memcg: check that kmem_cache has memcg_params before accessing it
If the system had a few memory groups and all of them were destroyed,
memcg_limited_groups_array_size has non-zero value, but all new caches
are created without memcg_params, because memcg_kmem_enabled() returns
false.

We try to enumirate child caches in a few places and all of them are
potentially dangerous.

For example my kernel is compiled with CONFIG_SLAB and it crashed when I
tryed to mount a NFS share after a few experiments with kmemcg.

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
  IP: [<ffffffff8118166a>] do_tune_cpucache+0x8a/0xd0
  PGD b942a067 PUD b999f067 PMD 0
  Oops: 0000 [#1] SMP
  Modules linked in: fscache(+) ip6table_filter ip6_tables iptable_filter ip_tables i2c_piix4 pcspkr virtio_net virtio_balloon i2c_core floppy
  CPU: 0 PID: 357 Comm: modprobe Not tainted 3.11.0-rc7+ #59
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  task: ffff8800b9f98240 ti: ffff8800ba32e000 task.ti: ffff8800ba32e000
  RIP: 0010:[<ffffffff8118166a>]  [<ffffffff8118166a>] do_tune_cpucache+0x8a/0xd0
  RSP: 0018:ffff8800ba32fb70  EFLAGS: 00010246
  RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000006
  RDX: 0000000000000000 RSI: ffff8800b9f98910 RDI: 0000000000000246
  RBP: ffff8800ba32fba0 R08: 0000000000000002 R09: 0000000000000004
  R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000010
  R13: 0000000000000008 R14: 00000000000000d0 R15: ffff8800375d0200
  FS:  00007f55f1378740(0000) GS:ffff8800bfa00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: 00007f24feba57a0 CR3: 0000000037b51000 CR4: 00000000000006f0
  Call Trace:
    enable_cpucache+0x49/0x100
    setup_cpu_cache+0x215/0x280
    __kmem_cache_create+0x2fa/0x450
    kmem_cache_create_memcg+0x214/0x350
    kmem_cache_create+0x2b/0x30
    fscache_init+0x19b/0x230 [fscache]
    do_one_initcall+0xfa/0x1b0
    load_module+0x1c41/0x26d0
    SyS_finit_module+0x86/0xb0
    system_call_fastpath+0x16/0x1b

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Glauber Costa <glommer@openvz.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-28 19:26:38 -07:00
..
backing-dev.c sysfs.h: add __ATTR_RW() macro 2013-07-16 10:57:36 -07:00
balloon_compaction.c
bootmem.c mm: kill free_all_bootmem_node() 2013-07-03 16:07:39 -07:00
bounce.c
cleancache.c
compaction.c
debug-pagealloc.c
dmapool.c
fadvise.c
failslab.c
filemap_xip.c
filemap.c mm: remove unused VM_<READfoo> macros and expand other in-place 2013-07-09 10:33:23 -07:00
fremap.c mm: save soft-dirty bits on file pages 2013-08-13 17:57:48 -07:00
frontswap.c
highmem.c
huge_memory.c thp, mm: avoid PageUnevictable on active/inactive lru lists 2013-07-31 14:41:03 -07:00
hugetlb_cgroup.c
hugetlb.c Fix TLB gather virtual address range invalidation corner cases 2013-08-16 08:52:46 -07:00
hwpoison-inject.c
init-mm.c
internal.h mm: remove unused __put_page() 2013-07-09 10:33:22 -07:00
interval_tree.c
Kconfig zswap: add to mm/ 2013-07-10 18:11:34 -07:00
Kconfig.debug
kmemcheck.c
kmemleak-test.c
kmemleak.c
ksm.c
maccess.c
madvise.c
Makefile zswap: add to mm/ 2013-07-10 18:11:34 -07:00
memblock.c mm/memblock.c: fix wrong comment in __next_free_mem_range() 2013-07-09 10:33:23 -07:00
memcontrol.c memcg: get rid of swapaccount leftovers 2013-08-23 09:51:22 -07:00
memory_hotplug.c mm/memory_hotplug.c: fix return value of online_pages() 2013-07-09 10:33:25 -07:00
memory-failure.c mm/memory-failure.c: fix memory leak in successful soft offlining 2013-07-03 16:07:31 -07:00
memory.c Fix TLB gather virtual address range invalidation corner cases 2013-08-16 08:52:46 -07:00
mempolicy.c mm: mempolicy: fix mbind_range() && vma_adjust() interaction 2013-07-31 14:41:02 -07:00
mempool.c
migrate.c
mincore.c
mlock.c
mm_init.c mm: tune vm_committed_as percpu_counter batching size 2013-07-03 16:07:32 -07:00
mmap.c Fix TLB gather virtual address range invalidation corner cases 2013-08-16 08:52:46 -07:00
mmu_context.c
mmu_notifier.c
mmzone.c
mprotect.c
mremap.c mm: move_ptes -- Set soft dirty bit depending on pte type 2013-08-27 09:36:17 -07:00
msync.c
nobootmem.c mm: concentrate modification of totalram_pages into the mm core 2013-07-03 16:07:33 -07:00
nommu.c mm: remove free_area_cache 2013-07-10 18:11:34 -07:00
oom_kill.c
page_alloc.c mm: honor min_free_kbytes set by user 2013-07-09 10:33:25 -07:00
page_cgroup.c
page_io.c mm: remove compressed copy from zram in-memory 2013-07-03 16:07:26 -07:00
page_isolation.c
page-writeback.c kernel: delete __cpuinit usage from all core kernel files 2013-07-14 19:36:59 -04:00
pagewalk.c
percpu-km.c
percpu-vm.c
percpu.c
pgtable-generic.c
process_vm_access.c
quicklist.c
readahead.c
rmap.c mm: save soft-dirty bits on file pages 2013-08-13 17:57:48 -07:00
shmem.c cope with potentially long ->d_dname() output for shmem/hugetlb 2013-08-24 12:10:17 -04:00
slab_common.c Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux 2013-07-14 15:14:29 -07:00
slab.c kernel: delete __cpuinit usage from all core kernel files 2013-07-14 19:36:59 -04:00
slab.h memcg: check that kmem_cache has memcg_params before accessing it 2013-08-28 19:26:38 -07:00
slob.c Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux 2013-07-14 15:14:29 -07:00
slub.c Revert "slub: do not put a slab to cpu partial list when cpu_partial is 0" 2013-08-08 09:06:37 -07:00
sparse-vmemmap.c
sparse.c mm/sparse.c: put clear_hwpoisoned_pages within CONFIG_MEMORY_HOTREMOVE 2013-07-09 10:33:22 -07:00
swap_state.c
swap.c thp, mm: avoid PageUnevictable on active/inactive lru lists 2013-07-31 14:41:03 -07:00
swapfile.c mm: save soft-dirty bits on swapped pages 2013-08-13 17:57:47 -07:00
truncate.c
util.c mm: remove free_area_cache 2013-07-10 18:11:34 -07:00
vmalloc.c mm/vmalloc.c: fix an overflow bug in alloc_vmap_area() 2013-07-09 10:33:23 -07:00
vmpressure.c vmpressure: make sure there are no events queued after memcg is offlined 2013-07-31 14:41:04 -07:00
vmscan.c mm: vmscan: do not scale writeback pages when deciding whether to set ZONE_WRITEBACK 2013-07-09 10:33:23 -07:00
vmstat.c kernel: delete __cpuinit usage from all core kernel files 2013-07-14 19:36:59 -04:00
zbud.c mm: zbud: fix condition check on allocation size 2013-07-31 14:41:03 -07:00
zswap.c zswap: add to mm/ 2013-07-10 18:11:34 -07:00