Tetsuo Handa bb422a738f mm,vmscan: Make unregister_shrinker() no-op if register_shrinker() failed. ... 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>		2017-12-18 15:03:09 -05:00
..
kasan	slab, slub, slob: add slab_flags_t	2017-11-15 18:21:01 -08:00
backing-dev.c	backing-dev: kill unused pdflush_proc_obsolete()	2017-10-06 08:15:15 -06:00
balloon_compaction.c	virtio_balloon: fix deadlock on OOM	2017-11-14 23:57:38 +02:00
bootmem.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
cleancache.c	fs: switch ->s_uuid to uuid_t	2017-06-05 16:59:12 +02:00
cma_debug.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
cma.c	mm/cma.c: change pr_info to pr_err for cma_alloc fail log	2017-11-15 18:21:03 -08:00
cma.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
compaction.c	mm, compaction: remove unneeded pageblock_skip_persistent() checks	2017-11-17 16:10:00 -08:00
debug_page_ref.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
debug.c	mm: consolidate page table accounting	2017-11-15 18:21:04 -08:00
dmapool.c	lib/vsprintf.c: remove %Z support	2017-02-27 18:43:47 -08:00
early_ioremap.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
fadvise.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
failslab.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
filemap.c	AFS development	2017-11-16 11:41:22 -08:00
frame_vector.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
frontswap.c	mm, frontswap: convert frontswap_enabled to static key	2016-07-26 16:19:19 -07:00
gup_benchmark.c	mm: add infrastructure for get_user_pages_fast() benchmarking	2017-11-17 16:10:04 -08:00
gup.c	Merge branch 'x86/urgent' into x86/mm, to pick up fixes	2017-10-20 13:06:52 +02:00
highmem.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
hmm.c	mm/hmm: remove redundant variable align_end	2017-11-15 18:21:07 -08:00
huge_memory.c	mm: consolidate page table accounting	2017-11-15 18:21:04 -08:00
hugetlb_cgroup.c	mm, hugetlb_cgroup: round limit_in_bytes down to hugepage size	2016-05-20 17:58:30 -07:00
hugetlb.c	mm/mmu_notifier: avoid double notification when it is useless	2017-11-15 18:21:03 -08:00
hwpoison-inject.c	mm: hwpoison: call shake_page() unconditionally	2017-05-03 15:52:12 -07:00
init-mm.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
internal.h	mm, compaction: split off flag for not updating skip hints	2017-11-17 16:10:00 -08:00
interval_tree.c	lib/interval_tree: fast overlap detection	2017-09-08 18:26:49 -07:00
Kconfig	mm: add infrastructure for get_user_pages_fast() benchmarking	2017-11-17 16:10:04 -08:00
Kconfig.debug	kmemcheck: rip it out	2017-11-15 18:21:05 -08:00
khugepaged.c	mm: introduce wrappers to access mm->nr_ptes	2017-11-15 18:21:04 -08:00
kmemcheck.c	kmemcheck: rip it out	2017-11-15 18:21:05 -08:00
kmemleak-test.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
kmemleak.c	kmemcheck: remove annotations	2017-11-15 18:21:04 -08:00
ksm.c	mm/mmu_notifier: avoid double notification when it is useless	2017-11-15 18:21:03 -08:00
list_lru.c	mm/list_lru.c: mark expected switch fall-through	2017-11-15 18:21:07 -08:00
maccess.c	x86: remove more uaccess_32.h complexity	2016-05-22 17:21:27 -07:00
madvise.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
Makefile	mm: add infrastructure for get_user_pages_fast() benchmarking	2017-11-17 16:10:04 -08:00
memblock.c	mm: define memblock_virt_alloc_try_nid_raw	2017-11-15 18:21:05 -08:00
memcontrol.c	mm: slabinfo: remove CONFIG_SLABINFO	2017-11-15 18:21:01 -08:00
memory_hotplug.c	memory hotplug: fix comments when adding section	2017-11-15 18:21:07 -08:00
memory-failure.c	mm, soft_offline: improve hugepage soft offlining error log	2017-11-15 18:21:05 -08:00
memory.c	mm: do not rely on preempt_count in print_vma_addr	2017-11-15 18:21:07 -08:00
mempolicy.c	mm, sysctl: make NUMA stats configurable	2017-11-15 18:21:07 -08:00
mempool.c	mm/mempool.c: use kmalloc_array_node()	2017-11-15 18:21:02 -08:00
memtest.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
migrate.c	mm/mmu_notifier: avoid call to invalidate_range() in range_end()	2017-11-15 18:21:03 -08:00
mincore.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
mlock.c	mm: mlock: remove lru_add_drain_all()	2017-11-15 18:21:07 -08:00
mm_init.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
mmap.c	mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags	2017-11-03 06:26:22 -07:00
mmu_context.c	sched/headers: Prepare to move the task_lock()/unlock() APIs to <linux/sched/task.h>	2017-03-02 08:42:38 +01:00
mmu_notifier.c	mm/mmu_notifier: avoid call to invalidate_range() in range_end()	2017-11-15 18:21:03 -08:00
mmzone.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
mprotect.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
mremap.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
msync.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
nobootmem.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
nommu.c	Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2017-09-14 18:13:32 -07:00
oom_kill.c	mm: simplify nodemask printing	2017-11-15 18:21:07 -08:00
page_alloc.c	mm, compaction: split off flag for not updating skip hints	2017-11-17 16:10:00 -08:00
page_counter.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
page_ext.c	mm/page_ext.c: check if page_ext is not prepared	2017-11-15 18:21:07 -08:00
page_idle.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
page_io.c	mm, swap: skip swapcache for swapin of synchronous device	2017-11-15 18:21:02 -08:00
page_isolation.c	mm: distinguish CMA and MOVABLE isolation in has_unmovable_pages()	2017-11-15 18:21:02 -08:00
page_owner.c	mm/page_owner.c: reduce page_owner structure size	2017-11-15 18:21:03 -08:00
page_poison.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
page_vma_mapped.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
page-writeback.c	block/laptop_mode: Convert timers to use timer_setup()	2017-11-21 15:46:44 -08:00
pagewalk.c	mm/pagewalk.c: report holes in hugetlb ranges	2017-11-15 13:12:08 -08:00
percpu-internal.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
percpu-km.c	percpu: replace area map allocator with bitmap	2017-07-26 17:41:05 -04:00
percpu-stats.c	percpu: fix starting offset for chunk statistics traversal	2017-09-27 14:45:57 -07:00
percpu-vm.c	mm: remove __GFP_COLD	2017-11-15 18:21:06 -08:00
percpu.c	Merge branch 'for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu	2017-11-15 14:17:11 -08:00
pgtable-generic.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
process_vm_access.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/mm.h>	2017-03-02 08:42:28 +01:00
quicklist.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
readahead.c	mm: don't cap request size based on read-ahead setting	2016-12-12 18:55:08 -08:00
rmap.c	mm: remove cold parameter from free_hot_cold_page*	2017-11-15 18:21:06 -08:00
rodata_test.c	mm: fix RODATA_TEST failure "rodata_test: test data was not read only"	2017-10-03 17:54:24 -07:00
shmem.c	mm: shmem: remove unused info variable	2017-11-17 16:10:00 -08:00
slab_common.c	kmemcheck: stop using GFP_NOTRACK and SLAB_NOTRACK	2017-11-15 18:21:04 -08:00
slab.c	kmemcheck: stop using GFP_NOTRACK and SLAB_NOTRACK	2017-11-15 18:21:04 -08:00
slab.h	kmemcheck: stop using GFP_NOTRACK and SLAB_NOTRACK	2017-11-15 18:21:04 -08:00
slob.c	slab, slub, slob: add slab_flags_t	2017-11-15 18:21:01 -08:00
slub.c	kmemcheck: rip it out	2017-11-15 18:21:05 -08:00
sparse-vmemmap.c	mm, sparse: do not swamp log with huge vmemmap allocation failures	2017-11-15 18:21:07 -08:00
sparse.c	mm: stop zeroing memory during allocation in vmemmap	2017-11-15 18:21:05 -08:00
swap_cgroup.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
swap_slots.c	mm/swap_slots.c: fix race conditions in swap_slots cache init	2017-11-15 18:21:03 -08:00
swap_state.c	mm: remove cold parameter for release_pages	2017-11-15 18:21:06 -08:00
swap.c	mm, pagevec: rename pagevec drained field	2017-11-15 18:21:06 -08:00
swapfile.c	mm: swap: SWP_SYNCHRONOUS_IO: skip swapcache only if swapped page has no other reference	2017-11-15 18:21:02 -08:00
truncate.c	mm, pagevec: remove cold parameter for pagevecs	2017-11-15 18:21:06 -08:00
usercopy.c	mm/usercopy: Drop extra is_vmalloc_or_module() check	2017-04-05 12:30:18 -07:00
userfaultfd.c	userfaultfd: shmem: wire up shmem_mfill_zeropage_pte	2017-09-06 17:27:28 -07:00
util.c	mm: rename global_page_state to global_zone_page_state	2017-09-06 17:27:29 -07:00
vmacache.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
vmalloc.c	Revert "vmalloc: back off when the current task is killed"	2017-10-13 16:18:32 -07:00
vmpressure.c	mm, vmpressure: pass-through notification support	2017-07-10 16:32:31 -07:00
vmscan.c	mm,vmscan: Make unregister_shrinker() no-op if register_shrinker() failed.	2017-12-18 15:03:09 -05:00
vmstat.c	mm, sysctl: make NUMA stats configurable	2017-11-15 18:21:07 -08:00
workingset.c	mm, truncate: do not check mapping for every page being truncated	2017-11-15 18:21:06 -08:00
z3fold.c	mm/z3fold.c: use kref to prevent page free/compact race	2017-11-17 16:10:00 -08:00
zbud.c	mm/zbud.c: use list_last_entry() instead of list_tail_entry()	2016-01-15 11:40:52 -08:00
zpool.c	mm: zsmalloc: constify struct zs_pool name	2015-11-06 17:50:42 -08:00
zsmalloc.c	zsmalloc: calling zs_map_object() from irq is a bug	2017-11-15 18:21:03 -08:00
zswap.c	mm/zswap.c: delete an error message for a failed memory allocation in zswap_dstmem_prepare()	2017-07-06 16:24:35 -07:00