linux/mm
Tetsuo Handa 0de023ab7d mm,vmscan: Make unregister_shrinker() no-op if register_shrinker() failed.
commit bb422a738f upstream.

Syzbot caught an oops at unregister_shrinker() because combination of
commit 1d3d4437ea ("vmscan: per-node deferred work") and fault
injection made register_shrinker() fail and the caller of
register_shrinker() did not check for failure.

----------
[  554.881422] FAULT_INJECTION: forcing a failure.
[  554.881422] name failslab, interval 1, probability 0, space 0, times 0
[  554.881438] CPU: 1 PID: 13231 Comm: syz-executor1 Not tainted 4.14.0-rc8+ #82
[  554.881443] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[  554.881445] Call Trace:
[  554.881459]  dump_stack+0x194/0x257
[  554.881474]  ? arch_local_irq_restore+0x53/0x53
[  554.881486]  ? find_held_lock+0x35/0x1d0
[  554.881507]  should_fail+0x8c0/0xa40
[  554.881522]  ? fault_create_debugfs_attr+0x1f0/0x1f0
[  554.881537]  ? check_noncircular+0x20/0x20
[  554.881546]  ? find_next_zero_bit+0x2c/0x40
[  554.881560]  ? ida_get_new_above+0x421/0x9d0
[  554.881577]  ? find_held_lock+0x35/0x1d0
[  554.881594]  ? __lock_is_held+0xb6/0x140
[  554.881628]  ? check_same_owner+0x320/0x320
[  554.881634]  ? lock_downgrade+0x990/0x990
[  554.881649]  ? find_held_lock+0x35/0x1d0
[  554.881672]  should_failslab+0xec/0x120
[  554.881684]  __kmalloc+0x63/0x760
[  554.881692]  ? lock_downgrade+0x990/0x990
[  554.881712]  ? register_shrinker+0x10e/0x2d0
[  554.881721]  ? trace_event_raw_event_module_request+0x320/0x320
[  554.881737]  register_shrinker+0x10e/0x2d0
[  554.881747]  ? prepare_kswapd_sleep+0x1f0/0x1f0
[  554.881755]  ? _down_write_nest_lock+0x120/0x120
[  554.881765]  ? memcpy+0x45/0x50
[  554.881785]  sget_userns+0xbcd/0xe20
(...snipped...)
[  554.898693] kasan: CONFIG_KASAN_INLINE enabled
[  554.898724] kasan: GPF could be caused by NULL-ptr deref or user memory access
[  554.898732] general protection fault: 0000 [#1] SMP KASAN
[  554.898737] Dumping ftrace buffer:
[  554.898741]    (ftrace buffer empty)
[  554.898743] Modules linked in:
[  554.898752] CPU: 1 PID: 13231 Comm: syz-executor1 Not tainted 4.14.0-rc8+ #82
[  554.898755] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[  554.898760] task: ffff8801d1dbe5c0 task.stack: ffff8801c9e38000
[  554.898772] RIP: 0010:__list_del_entry_valid+0x7e/0x150
[  554.898775] RSP: 0018:ffff8801c9e3f108 EFLAGS: 00010246
[  554.898780] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
[  554.898784] RDX: 0000000000000000 RSI: ffff8801c53c6f98 RDI: ffff8801c53c6fa0
[  554.898788] RBP: ffff8801c9e3f120 R08: 1ffff100393c7d55 R09: 0000000000000004
[  554.898791] R10: ffff8801c9e3ef70 R11: 0000000000000000 R12: 0000000000000000
[  554.898795] R13: dffffc0000000000 R14: 1ffff100393c7e45 R15: ffff8801c53c6f98
[  554.898800] FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
[  554.898804] CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
[  554.898807] CR2: 00000000dbc23000 CR3: 00000001c7269000 CR4: 00000000001406e0
[  554.898813] DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
[  554.898816] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
[  554.898818] Call Trace:
[  554.898828]  unregister_shrinker+0x79/0x300
[  554.898837]  ? perf_trace_mm_vmscan_writepage+0x750/0x750
[  554.898844]  ? down_write+0x87/0x120
[  554.898851]  ? deactivate_super+0x139/0x1b0
[  554.898857]  ? down_read+0x150/0x150
[  554.898864]  ? check_same_owner+0x320/0x320
[  554.898875]  deactivate_locked_super+0x64/0xd0
[  554.898883]  deactivate_super+0x141/0x1b0
----------

Since allowing register_shrinker() callers to call unregister_shrinker()
when register_shrinker() failed can simplify error recovery path, this
patch makes unregister_shrinker() no-op when register_shrinker() failed.
Also, reset shrinker->nr_deferred in case unregister_shrinker() was
by error called twice.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Aliaksei Karaliou <akaraliou.dev@gmail.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Glauber Costa <glauber@scylladb.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-25 11:03:35 +01:00
..
kasan kasan: respect /proc/sys/kernel/traceoff_on_warning 2017-06-17 06:39:36 +02:00
backing-dev.c block: fix double-free in the failure path of cgwb_bdi_init() 2017-02-26 11:07:51 +01:00
balloon_compaction.c virtio_balloon: fix race between migration and ballooning 2016-03-03 15:07:18 -08:00
bootmem.c
cleancache.c
cma_debug.c
cma.c cma: fix calculation of aligned offset 2018-01-31 12:06:09 +01:00
cma.h
compaction.c mm/compaction: pass only pageblock aligned range to pageblock_pfn_to_page 2018-01-17 09:35:26 +01:00
debug-pagealloc.c mm, hwpoison: fixup "mm: check the return value of lookup_page_ext for all call sites" 2017-11-24 11:26:29 +01:00
debug.c
dmapool.c
early_ioremap.c
fadvise.c
failslab.c
filemap.c mm: do not access page->mapping directly on page_endio 2017-03-12 06:37:25 +01:00
frame_vector.c
frontswap.c
gup.c mm: larger stack guard gap, between vmas 2017-06-26 07:13:11 +02:00
highmem.c
huge_memory.c thp: fix MADV_DONTNEED vs. numa balancing race 2017-12-16 10:33:50 +01:00
hugetlb_cgroup.c
hugetlb.c mm, hugetlb: use pte_present() instead of pmd_present() in follow_huge_pmd() 2017-04-08 09:53:32 +02:00
hwpoison-inject.c
init-mm.c mm: Add a user_ns owner to mm_struct and fix ptrace permission checks 2017-01-06 11:16:11 +01:00
internal.h mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries 2017-08-11 09:08:50 -07:00
interval_tree.c
Kconfig
Kconfig.debug
kmemcheck.c
kmemleak-test.c
kmemleak.c kmemleak: add scheduling point to kmemleak_scan() 2018-02-03 17:04:29 +01:00
ksm.c mm,ksm: fix endless looping in allocating memory when ksm enable 2016-10-07 15:23:40 +02:00
list_lru.c mm/list_lru.c: fix list_lru_count_node() to be race free 2017-07-21 07:44:56 +02:00
maccess.c
madvise.c mm/madvise.c: fix madvise() infinite loop under special circumstances 2017-12-05 11:22:50 +01:00
Makefile
memblock.c mm: consider memblock reservations for deferred memory initialization sizing 2017-06-14 13:16:26 +02:00
memcontrol.c hwpoison, memcg: forcibly uncharge LRU pages 2018-01-31 12:06:09 +01:00
memory_hotplug.c base/memory, hotplug: fix a kernel oops in show_valid_zones() 2017-02-09 08:02:47 +01:00
memory-failure.c hwpoison, memcg: forcibly uncharge LRU pages 2018-01-31 12:06:09 +01:00
memory.c mm: hide a #warning for COMPILE_TEST 2018-02-22 15:45:00 +01:00
mempolicy.c mm/mempolicy: fix use after free when calling get_mempolicy 2017-08-24 17:02:35 -07:00
mempool.c mm/mempool: avoid KASAN marking mempool poison checks as use-after-free 2017-08-12 19:29:09 -07:00
memtest.c
migrate.c Sanitize 'move_pages()' permission checks 2017-08-24 17:02:36 -07:00
mincore.c
mlock.c mlock: fix mlock count can not decrease in race condition 2017-06-07 12:06:01 +02:00
mm_init.c
mmap.c mm/mmap.c: do not blow on PROT_NONE MAP_FIXED holes in the stack 2018-01-31 12:06:09 +01:00
mmu_context.c mm/mmu_context, sched/core: Fix mmu_context.h assumption 2017-12-25 14:22:09 +01:00
mmu_notifier.c
mmzone.c
mprotect.c mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries 2017-08-11 09:08:50 -07:00
mremap.c mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries 2017-08-11 09:08:50 -07:00
msync.c
nobootmem.c
nommu.c
oom_kill.c
page_alloc.c mm, page_alloc: fix potential false positive in __zone_watermark_ok 2018-01-31 12:06:09 +01:00
page_counter.c
page_ext.c mm/page_ext.c: check if page_ext is not prepared 2017-11-24 08:32:25 +01:00
page_idle.c
page_io.c
page_isolation.c mm: fix invalid node in alloc_migrate_target() 2016-04-20 15:41:53 +09:00
page_owner.c mm: check the return value of lookup_page_ext for all call sites 2017-11-24 08:32:25 +01:00
page-writeback.c mm/page-writeback: fix dirty_ratelimit calculation 2018-01-17 09:35:27 +01:00
pagewalk.c mm/pagewalk.c: report holes in hugetlb ranges 2017-11-24 08:32:25 +01:00
percpu-km.c
percpu-vm.c
percpu.c percpu: acquire pcpu_lock when updating pcpu_nr_empty_pop_pages 2017-03-26 12:13:20 +02:00
pgtable-generic.c
process_vm_access.c
quicklist.c
readahead.c
rmap.c mm/rmap: batched invalidations should use existing api 2017-12-25 14:22:09 +01:00
shmem.c tmpfs: fix regression hang in fallocate undo 2016-07-27 09:47:40 -07:00
slab_common.c slub: do not merge cache if slub_debug contains a never-merge flag 2017-10-21 17:09:05 +02:00
slab.c
slab.h
slob.c
slub.c slub/memcg: cure the brainless abuse of sysfs attributes 2017-06-07 12:06:01 +02:00
sparse-vmemmap.c
sparse.c
swap_cgroup.c mm, swap_cgroup: reschedule when neeed in swap_cgroup_swapoff() 2017-07-05 14:37:15 +02:00
swap_state.c
swap.c
swapfile.c swapfile: fix memory corruption via malformed swapfile 2016-11-18 10:48:34 +01:00
truncate.c fs: add i_blocksize() 2017-06-14 13:16:24 +02:00
userfaultfd.c
util.c proc: revert /proc/<pid>/maps [stack:TID] annotation 2016-09-15 08:27:46 +02:00
vmacache.c
vmalloc.c
vmpressure.c mm: vmpressure: fix sending wrong events on underflow 2017-03-12 06:37:25 +01:00
vmscan.c mm,vmscan: Make unregister_shrinker() no-op if register_shrinker() failed. 2018-02-25 11:03:35 +01:00
vmstat.c proc: much faster /proc/vmstat 2018-01-10 09:27:14 +01:00
workingset.c mm: workingset: fix crash in shadow node shrinker caused by replace_page_cache_page() 2016-10-28 03:01:34 -04:00
zbud.c
zpool.c
zsmalloc.c zsmalloc: fix zs_can_compact() integer overflow 2016-05-18 17:06:44 -07:00
zswap.c zswap: don't param_set_charp while holding spinlock 2018-01-17 09:35:27 +01:00