============================================ WARNING: possible recursive locking detected 5.3.0-rc6-next-20190830 #75 Not tainted -------------------------------------------- oom_reaper/1065 is trying to acquire lock: ffffffff8904ff60 (mmu_notifier_invalidate_range_start){+.+.}, at: __mmu_notifier_invalidate_range_end+0x0/0x360 mm/mmu_notifier.c:169 but task is already holding lock: ffffffff8904ff60 (mmu_notifier_invalidate_range_start){+.+.}, at: __oom_reap_task_mm+0x196/0x490 mm/oom_kill.c:542 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(mmu_notifier_invalidate_range_start); lock(mmu_notifier_invalidate_range_start); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by oom_reaper/1065: #0: ffff88803f1f6590 (&mm->mmap_sem#2){++++}, at: oom_reap_task_mm mm/oom_kill.c:570 [inline] #0: ffff88803f1f6590 (&mm->mmap_sem#2){++++}, at: oom_reap_task mm/oom_kill.c:613 [inline] #0: ffff88803f1f6590 (&mm->mmap_sem#2){++++}, at: oom_reaper+0x3a7/0x1320 mm/oom_kill.c:651 #1: ffffffff8904ff60 (mmu_notifier_invalidate_range_start){+.+.}, at: __oom_reap_task_mm+0x196/0x490 mm/oom_kill.c:542 stack backtrace: CPU: 1 PID: 1065 Comm: oom_reaper Not tainted 5.3.0-rc6-next-20190830 #75 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_deadlock_bug kernel/locking/lockdep.c:2371 [inline] check_deadlock kernel/locking/lockdep.c:2412 [inline] validate_chain kernel/locking/lockdep.c:2955 [inline] __lock_acquire.cold+0x15d/0x385 kernel/locking/lockdep.c:3955 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487 __mmu_notifier_invalidate_range_end+0x3c/0x360 mm/mmu_notifier.c:193 mmu_notifier_invalidate_range_end include/linux/mmu_notifier.h:375 [inline] __oom_reap_task_mm+0x3fa/0x490 mm/oom_kill.c:552 oom_reap_task_mm mm/oom_kill.c:589 [inline] oom_reap_task mm/oom_kill.c:613 [inline] oom_reaper+0x2b2/0x1320 mm/oom_kill.c:651 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 oom_reaper: reaped process 28617 (syz-executor.4), now anon-rss:0kB, file-rss:34888kB, shmem-rss:0kB oom_reaper: reaped process 22168 (syz-executor.4), now anon-rss:0kB, file-rss:34888kB, shmem-rss:0kB oom_reaper: reaped process 28785 (syz-executor.4), now anon-rss:0kB, file-rss:34860kB, shmem-rss:0kB oom_reaper: reaped process 22076 (syz-executor.4), now anon-rss:0kB, file-rss:34848kB, shmem-rss:0kB oom_reaper: reaped process 28714 (syz-executor.4), now anon-rss:0kB, file-rss:34844kB, shmem-rss:0kB oom_reaper: reaped process 13054 (syz-executor.4), now anon-rss:0kB, file-rss:34828kB, shmem-rss:0kB oom_reaper: reaped process 29047 (syz-executor.4), now anon-rss:0kB, file-rss:34840kB, shmem-rss:0kB oom_reaper: reaped process 29015 (syz-executor.4), now anon-rss:0kB, file-rss:34840kB, shmem-rss:0kB oom_reaper: reaped process 27838 (syz-executor.4), now anon-rss:0kB, file-rss:34840kB, shmem-rss:0kB oom_reaper: reaped process 18726 (syz-executor.4), now anon-rss:0kB, file-rss:34848kB, shmem-rss:0kB oom_reaper: reaped process 18708 (syz-executor.4), now anon-rss:0kB, file-rss:34848kB, shmem-rss:0kB oom_reaper: reaped process 18656 (syz-executor.4), now anon-rss:0kB, file-rss:34832kB, shmem-rss:0kB oom_reaper: reaped process 29266 (syz-executor.4), now anon-rss:0kB, file-rss:34836kB, shmem-rss:0kB oom_reaper: reaped process 17970 (syz-executor.4), now anon-rss:0kB, file-rss:34828kB, shmem-rss:0kB oom_reaper: reaped process 29595 (syz-executor.4), now anon-rss:0kB, file-rss:34840kB, shmem-rss:0kB oom_reaper: reaped process 29161 (syz-executor.4), now anon-rss:0kB, file-rss:34832kB, shmem-rss:0kB oom_reaper: reaped process 29580 (syz-executor.4), now anon-rss:0kB, file-rss:34828kB, shmem-rss:0kB oom_reaper: reaped process 29301 (syz-executor.4), now anon-rss:0kB, file-rss:34828kB, shmem-rss:0kB oom_reaper: reaped process 29170 (syz-executor.4), now anon-rss:0kB, file-rss:34828kB, shmem-rss:0kB oom_reaper: reaped process 29206 (syz-executor.4), now anon-rss:0kB, file-rss:34832kB, shmem-rss:0kB oom_reaper: reaped process 29133 (syz-executor.4), now anon-rss:0kB, file-rss:34824kB, shmem-rss:0kB oom_reaper: reaped process 29115 (syz-executor.4), now anon-rss:0kB, file-rss:34824kB, shmem-rss:0kB oom_reaper: reaped process 28860 (syz-executor.4), now anon-rss:0kB, file-rss:34832kB, shmem-rss:0kB oom_reaper: reaped process 10584 (syz-executor.4), now anon-rss:0kB, file-rss:34824kB, shmem-rss:0kB oom_reaper: reaped process 28847 (syz-executor.4), now anon-rss:0kB, file-rss:34828kB, shmem-rss:0kB oom_reaper: reaped process 27818 (syz-executor.4), now anon-rss:0kB, file-rss:34824kB, shmem-rss:0kB