syzbot

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[ BUG: Invalid wait context ]
5.7.0-rc6-next-20200519-syzkaller #0 Not tainted
-----------------------------
swapper/0/0 is trying to lock:
ffff88821bc47318 (&parent->list_lock){-...}-{3:3}, at: spin_lock include/linux/spinlock.h:353 [inline]
ffff88821bc47318 (&parent->list_lock){-...}-{3:3}, at: __drain_alien_cache+0x2e/0x70 mm/slab.c:691
other info that might help us debug this:
context-{2:2}
1 lock held by swapper/0/0:
 #0: ffff8880aa1ebb18 (&alc->lock){-...}-{3:3}, at: spin_lock include/linux/spinlock.h:353 [inline]
 #0: ffff8880aa1ebb18 (&alc->lock){-...}-{3:3}, at: __cache_free_alien mm/slab.c:765 [inline]
 #0: ffff8880aa1ebb18 (&alc->lock){-...}-{3:3}, at: cache_free_alien mm/slab.c:794 [inline]
 #0: ffff8880aa1ebb18 (&alc->lock){-...}-{3:3}, at: ___cache_free+0x135/0x3a0 mm/slab.c:3450
stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-rc6-next-20200519-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x18f/0x20d lib/dump_stack.c:118
 print_lock_invalid_wait_context kernel/locking/lockdep.c:3988 [inline]
 check_wait_context kernel/locking/lockdep.c:4049 [inline]
 __lock_acquire.cold+0x26c/0x458 kernel/locking/lockdep.c:4286
 lock_acquire+0x20e/0x960 kernel/locking/lockdep.c:4915
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
 spin_lock include/linux/spinlock.h:353 [inline]
 __drain_alien_cache+0x2e/0x70 mm/slab.c:691
 __cache_free_alien mm/slab.c:768 [inline]
 cache_free_alien mm/slab.c:794 [inline]
 ___cache_free+0x38b/0x3a0 mm/slab.c:3450
 qlink_free mm/kasan/quarantine.c:148 [inline]
 qlist_free_all+0x79/0x140 mm/kasan/quarantine.c:167
 per_cpu_remove_cache+0x52/0x60 mm/kasan/quarantine.c:296
 flush_smp_call_function_queue+0x17d/0x550 kernel/smp.c:244
 smp_call_function_single_interrupt+0x103/0x550 arch/x86/kernel/smp.c:262
 call_function_single_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:850
 </IRQ>
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: cc cc cc cc cc cc cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d 74 91 59 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 64 91 59 00 fb f4 <c3> cc 48 b8 00 00 00 00 00 fc ff df 41 57 41 56 41 55 41 54 55 53
RSP: 0000:ffffffff89a07d30 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff04
RAX: 1ffffffff1369a43 RBX: 1ffffffff1340fa7 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffffffff89a86e4c
RBP: dffffc0000000000 R08: ffffffff89a86580 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: fffffbfff1350cb0
R13: 0000000000000000 R14: ffffffff8aabeb08 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:150 [inline]
 default_idle+0x91/0x3d0 arch/x86/kernel/process.c:708
 cpuidle_idle_call kernel/sched/idle.c:154 [inline]
 do_idle+0x393/0x690 kernel/sched/idle.c:269
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:361
 start_kernel+0x9be/0x9fb init/main.c:1042
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242