linux/mm
Mikulas Patocka 03e5ac2fc3 mm: fix crash when using XFS on loopback
Commit 8456a648cf ("slab: use struct page for slab management") causes
a crash in the LVM2 testsuite on PA-RISC (the crashing test is
fsadm.sh).  The testsuite doesn't crash on 3.12, crashes on 3.13-rc1 and
later.

 Bad Address (null pointer deref?): Code=15 regs=000000413edd89a0 (Addr=000006202224647d)
 CPU: 3 PID: 24008 Comm: loop0 Not tainted 3.13.0-rc6 #5
 task: 00000001bf3c0048 ti: 000000413edd8000 task.ti: 000000413edd8000

      YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
 PSW: 00001000000001101111100100001110 Not tainted
 r00-03  000000ff0806f90e 00000000405c8de0 000000004013e6c0 000000413edd83f0
 r04-07  00000000405a95e0 0000000000000200 00000001414735f0 00000001bf349e40
 r08-11  0000000010fe3d10 0000000000000001 00000040829c7778 000000413efd9000
 r12-15  0000000000000000 000000004060d800 0000000010fe3000 0000000010fe3000
 r16-19  000000413edd82a0 00000041078ddbc0 0000000000000010 0000000000000001
 r20-23  0008f3d0d83a8000 0000000000000000 00000040829c7778 0000000000000080
 r24-27  00000001bf349e40 00000001bf349e40 202d66202224640d 00000000405a95e0
 r28-31  202d662022246465 000000413edd88f0 000000413edd89a0 0000000000000001
 sr00-03  000000000532c000 0000000000000000 0000000000000000 000000000532c000
 sr04-07  0000000000000000 0000000000000000 0000000000000000 0000000000000000

 IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000401fe42c 00000000401fe430
  IIR: 539c0030    ISR: 00000000202d6000  IOR: 000006202224647d
  CPU:        3   CR30: 000000413edd8000 CR31: 0000000000000000
  ORIG_R28: 00000000405a95e0
  IAOQ[0]: vma_interval_tree_iter_first+0x14/0x48
  IAOQ[1]: vma_interval_tree_iter_first+0x18/0x48
  RP(r2): flush_dcache_page+0x128/0x388
 Backtrace:
   flush_dcache_page+0x128/0x388
   lo_splice_actor+0x90/0x148 [loop]
   splice_from_pipe_feed+0xc0/0x1d0
   __splice_from_pipe+0xac/0xc0
   lo_direct_splice_actor+0x1c/0x70 [loop]
   splice_direct_to_actor+0xec/0x228
   lo_receive+0xe4/0x298 [loop]
   loop_thread+0x478/0x640 [loop]
   kthread+0x134/0x168
   end_fault_vector+0x20/0x28
   xfs_setsize_buftarg+0x0/0x90 [xfs]

 Kernel panic - not syncing: Bad Address (null pointer deref?)

Commit 8456a648cf changes the page structure so that the slab
subsystem reuses the page->mapping field.

The crash happens in the following way:
 * XFS allocates some memory from slab and issues a bio to read data
   into it.
 * the bio is sent to the loopback device.
 * lo_receive creates an actor and calls splice_direct_to_actor.
 * lo_splice_actor copies data to the target page.
 * lo_splice_actor calls flush_dcache_page because the page may be
   mapped by userspace.  In that case we need to flush the kernel cache.
 * flush_dcache_page asks for the list of userspace mappings, however
   that page->mapping field is reused by the slab subsystem for a
   different purpose.  This causes the crash.

Note that other architectures without coherent caches (sparc, arm, mips)
also call page_mapping from flush_dcache_page, so they may crash in the
same way.

This patch fixes this bug by testing if the page is a slab page in
page_mapping and returning NULL if it is.

The patch also fixes VM_BUG_ON(PageSlab(page)) that could happen in
earlier kernels in the same scenario on architectures without cache
coherence when CONFIG_DEBUG_VM is enabled - so it should be backported
to stable kernels.

In the old kernels, the function page_mapping is placed in
include/linux/mm.h, so you should modify the patch accordingly when
backporting it.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: John David Anglin <dave.anglin@bell.net>]
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Lameter <cl@linux.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-15 14:19:42 +07:00
..
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: introduce a common interface for balloon pages mobility 2012-12-11 17:22:26 -08:00
bootmem.c mm/bootmem.c: remove unused local `map' 2013-11-13 12:09:09 +09:00
bounce.c mm/bounce.c: fix a regression where MS_SNAP_STABLE (stable pages snapshotting) was ignored 2013-09-30 14:31:02 -07:00
cleancache.c mm: cleancache: clean up cleancache_enabled 2013-04-30 17:04:01 -07:00
compaction.c mm/compaction: respect ignore_skip_hint in update_pageblock_skip 2013-12-18 19:04:52 -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 mm: drop actor argument of do_generic_file_read() 2013-11-15 09:32:13 +09:00
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 thp: fix copy_page_rep GPF by testing is_huge_zero_pmd once only 2014-01-12 16:47:15 +07:00
hugetlb_cgroup.c cgroup: pass around cgroup_subsys_state instead of cgroup in file methods 2013-08-08 20:11:24 -04:00
hugetlb.c mm: hugetlbfs: fix hugetlbfs optimization 2013-11-21 16:42:27 -08:00
hwpoison-inject.c mm/hwpoison: fix the lack of one reference count against poisoned page 2013-09-30 14:31:03 -07:00
init-mm.c
internal.h mm: vmscan: fix do_try_to_free_pages() livelock 2013-09-11 15:58:01 -07:00
interval_tree.c
Kconfig mm: add missing dependency in Kconfig 2013-12-18 19:04:52 -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 ksm: remove redundant __GFP_ZERO from kcalloc 2013-11-13 12:09:02 +09:00
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 list: add a new LRU list type 2013-09-10 18:56:30 -04:00
memblock.c mm/memblock.c: introduce bottom-up allocation mode 2013-11-13 12:09:08 +09:00
memcontrol.c memcg: fix memcg_size() calculation 2014-01-02 14:40:30 -08:00
memory_hotplug.c mem-hotplug: introduce movable_node boot option 2013-11-13 12:09:09 +09:00
memory-failure.c mm/memory-failure.c: transfer page count from head page to tail page after split thp 2014-01-02 14:40:30 -08:00
memory.c mm: fix build of split ptlock code 2013-12-20 15:41:27 -08:00
mempolicy.c mm/mempolicy: fix !vma in new_vma_page() 2013-12-18 19:04:52 -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 aio/migratepages: make aio migrate pages sane 2013-12-21 17:56:08 -05:00
mincore.c swap: make each swap partition have one address_space 2013-02-23 17:50:17 -08:00
mlock.c mm: munlock: fix deadlock in __munlock_pagevec() 2014-01-02 14:40:30 -08:00
mm_init.c mm: numa: Change page last {nid,pid} into {cpu,pid} 2013-10-09 14:47:45 +02:00
mmap.c mm: convert mm->nr_ptes to atomic_long_t 2013-11-15 09:32:14 +09:00
mmu_context.c mm: remove old aio use_mm() comment 2013-05-07 18:38:27 -07:00
mmu_notifier.c treewide: relase -> release 2013-06-28 14:34:33 +02:00
mmzone.c mm: numa: Change page last {nid,pid} into {cpu,pid} 2013-10-09 14:47:45 +02:00
mprotect.c mm: fix TLB flush race between migration, and change_protection_range 2013-12-18 19:04:51 -08:00
mremap.c mm: revert mremap pud_free anti-fix 2013-10-16 21:35:53 -07:00
msync.c
nobootmem.c mm/nobootmem.c: have __free_pages_memory() free in larger chunks. 2013-11-13 12:09:04 +09:00
nommu.c Merge branch 'akpm' (patches from Andrew Morton) 2013-11-13 15:45:43 +09:00
oom_kill.c mm: convert mm->nr_ptes to atomic_long_t 2013-11-15 09:32:14 +09:00
page_alloc.c mm: page_alloc: revert NUMA aspect of fair allocation policy 2013-12-20 12:19:18 -08:00
page_cgroup.c memcontrol: use N_MEMORY instead N_HIGH_MEMORY 2012-12-12 17:38:32 -08:00
page_io.c aio: Kill aio_rw_vect_retry() 2013-07-30 11:53:12 -04:00
page_isolation.c mm: memory-hotplug: enable memory hotplug to handle hugepage 2013-09-11 15:57:48 -07:00
page-writeback.c writeback: fix negative bdi max pause 2013-10-16 21:35:53 -07:00
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
percpu.c percpu: fix bootmem error handling in pcpu_page_first_chunk() 2013-09-23 10:51:45 -04:00
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 readahead: fix sequential read cache miss detection 2013-11-13 12:09:09 +09:00
rmap.c mm/hugetlb: check for pte NULL pointer in __page_check_address() 2013-12-18 19:04:52 -08:00
shmem.c security: shmem: implement kernel private shmem inodes 2013-12-02 11:24:19 +00:00
slab_common.c memcg, kmem: rename cache_from_memcg to cache_from_memcg_idx 2013-11-13 12:09:10 +09:00
slab.c Merge branch 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux 2013-11-22 08:10:34 -08:00
slab.h memcg, kmem: rename cache_from_memcg to cache_from_memcg_idx 2013-11-13 12:09:10 +09:00
slob.c mm/sl[aou]b: Move kmallocXXX functions to common code 2013-09-04 20:51:33 +03:00
slub.c Merge branch 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux 2013-11-22 08:10:34 -08:00
sparse-vmemmap.c sparse-vmemmap: specify vmemmap population range in bytes 2013-04-29 15:54:35 -07:00
sparse.c mm/sparsemem: fix a bug in free_map_bootmem when CONFIG_SPARSEMEM_VMEMMAP 2013-11-13 12:09:06 +09:00
swap_state.c lib/radix-tree.c: make radix_tree_node_alloc() work correctly within interrupt 2013-09-11 15:59:36 -07:00
swap.c mm: hugetlbfs: fix hugetlbfs optimization 2013-11-21 16:42:27 -08:00
swapfile.c frontswap: enable call to invalidate area on swapoff 2013-11-13 12:09:07 +09:00
truncate.c truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
util.c mm: fix crash when using XFS on loopback 2014-01-15 14:19:42 +07:00
vmalloc.c mm: kmemleak: avoid false negatives on vmalloc'ed objects 2013-11-13 12:09:07 +09:00
vmpressure.c Merge branch 'for-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2013-09-03 18:25:03 -07:00
vmscan.c mm/vmscan.c: don't forget to free shrinker->nr_deferred 2013-10-16 21:35:52 -07:00
vmstat.c mm: numa: return the number of base pages altered by protection changes 2013-11-13 12:09:11 +09:00
zbud.c mm/zbud: fix some trivial typos in comments 2013-09-11 15:57:35 -07:00
zswap.c mm/zswap: refactor the get/put routines 2013-11-13 12:09:11 +09:00