rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=101693, q=933) rcu: All QSes seen, last rcu_preempt kthread activity 10434 (4295017098-4295006664), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10435 jiffies! g101693 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:28816 pid: 13 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 schedule_timeout+0x148/0x250 kernel/time/timer.c:1878 rcu_gp_fqs_loop kernel/rcu/tree.c:1940 [inline] rcu_gp_kthread+0xbbe/0x1d70 kernel/rcu/tree.c:2113 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 ================================ WARNING: inconsistent lock state 5.11.0-rc7-syzkaller #0 Not tainted -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. syz-executor.1/18365 [HC0[0]:SC1[1]:HE0:SE0] takes: ffffffff8bd7c058 (rcu_node_0){?.-.}-{2:2}, at: print_other_cpu_stall kernel/rcu/tree_stall.h:493 [inline] ffffffff8bd7c058 (rcu_node_0){?.-.}-{2:2}, at: check_cpu_stall kernel/rcu/tree_stall.h:652 [inline] ffffffff8bd7c058 (rcu_node_0){?.-.}-{2:2}, at: rcu_pending kernel/rcu/tree.c:3751 [inline] ffffffff8bd7c058 (rcu_node_0){?.-.}-{2:2}, at: rcu_sched_clock_irq.cold+0xbc/0xedf kernel/rcu/tree.c:2580 {IN-HARDIRQ-W} state was registered at: lock_acquire kernel/locking/lockdep.c:5442 [inline] lock_acquire+0x1a8/0x720 kernel/locking/lockdep.c:5407 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 rcu_report_exp_cpu_mult+0x72/0x320 kernel/rcu/tree_exp.h:237 flush_smp_call_function_queue+0x34b/0x640 kernel/smp.c:425 __sysvec_call_function_single+0x95/0x3d0 arch/x86/kernel/smp.c:248 asm_call_irq_on_stack+0xf/0x20 __run_sysvec_on_irqstack arch/x86/include/asm/irq_stack.h:37 [inline] run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:89 [inline] sysvec_call_function_single+0xbd/0x100 arch/x86/kernel/smp.c:243 asm_sysvec_call_function_single+0x12/0x20 arch/x86/include/asm/idtentry.h:637 stack_depot_save+0xf3/0x4e0 lib/stackdepot.c:256 kasan_save_stack+0x32/0x40 mm/kasan/common.c:40 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:401 [inline] ____kasan_kmalloc.constprop.0+0x82/0xa0 mm/kasan/common.c:429 kasan_slab_alloc include/linux/kasan.h:209 [inline] slab_post_alloc_hook mm/slab.h:512 [inline] slab_alloc_node mm/slub.c:2892 [inline] slab_alloc mm/slub.c:2900 [inline] __kmalloc+0x1db/0x3e0 mm/slub.c:3967 kmalloc include/linux/slab.h:557 [inline] kzalloc include/linux/slab.h:682 [inline] lsm_cred_alloc security/security.c:534 [inline] security_prepare_creds+0x10e/0x190 security/security.c:1633 prepare_kernel_cred+0x465/0x800 kernel/cred.c:719 call_usermodehelper_exec_async+0x10e/0x580 kernel/umh.c:90 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 irq event stamp: 12743543 hardirqs last enabled at (12743542): [] asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:629 hardirqs last disabled at (12743543): [] sysvec_apic_timer_interrupt+0xc/0x100 arch/x86/kernel/apic/apic.c:1100 softirqs last enabled at (88360): [] asm_call_irq_on_stack+0xf/0x20 softirqs last disabled at (88723): [] asm_call_irq_on_stack+0xf/0x20 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(rcu_node_0); lock(rcu_node_0); *** DEADLOCK *** 5 locks held by syz-executor.1/18365: #0: ffff888082224440 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1087 [inline] #0: ffff888082224440 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_make_ready+0xc7/0x1b0 sound/core/oss/pcm_oss.c:1149 #1: ffffffff8be89240 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_acquire+0xf7/0x150 mm/page_alloc.c:4348 #2: ffffffff8bea4120 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: fs_reclaim_acquire+0xb2/0x150 mm/page_alloc.c:4339 #3: ffffc90000007d90 ((&q->adapt_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:35 [inline] #3: ffffc90000007d90 ((&q->adapt_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 kernel/time/timer.c:1407 #4: ffffffff8bd7c058 (rcu_node_0){?.-.}-{2:2}, at: print_other_cpu_stall kernel/rcu/tree_stall.h:493 [inline] #4: ffffffff8bd7c058 (rcu_node_0){?.-.}-{2:2}, at: check_cpu_stall kernel/rcu/tree_stall.h:652 [inline] #4: ffffffff8bd7c058 (rcu_node_0){?.-.}-{2:2}, at: rcu_pending kernel/rcu/tree.c:3751 [inline] #4: ffffffff8bd7c058 (rcu_node_0){?.-.}-{2:2}, at: rcu_sched_clock_irq.cold+0xbc/0xedf kernel/rcu/tree.c:2580 stack backtrace: CPU: 0 PID: 18365 Comm: syz-executor.1 Not tainted 5.11.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 print_usage_bug kernel/locking/lockdep.c:4413 [inline] valid_state kernel/locking/lockdep.c:3751 [inline] mark_lock_irq kernel/locking/lockdep.c:3954 [inline] mark_lock.cold+0x56/0x73 kernel/locking/lockdep.c:4411 mark_held_locks+0x9f/0xe0 kernel/locking/lockdep.c:4012 __trace_hardirqs_on_caller kernel/locking/lockdep.c:4030 [inline] lockdep_hardirqs_on_prepare kernel/locking/lockdep.c:4098 [inline] lockdep_hardirqs_on_prepare+0x135/0x400 kernel/locking/lockdep.c:4050 trace_hardirqs_on+0x5b/0x1c0 kernel/trace/trace_preemptirq.c:49 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:629 RIP: 0010:lock_acquire+0x1d2/0x720 kernel/locking/lockdep.c:5410 Code: 48 c7 c7 a0 a9 4b 89 48 83 c4 20 e8 28 ca a1 07 b8 ff ff ff ff 65 0f c1 05 ab 2a a9 7e 83 f8 01 0f 85 da 03 00 00 ff 34 24 9d <48> b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00 00 00 00 48 c7 RSP: 0018:ffffc90000007c68 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 1ffff92000000f8f RCX: 0000000000000001 RDX: 1ffff11005064130 RSI: 0000000000000102 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8f866907 R10: fffffbfff1f0cd20 R11: 0000000000000000 R12: 0000000000000000 R13: ffffc90000007d90 R14: 0000000000000000 R15: 0000000000000000 call_timer_fn+0x12b/0x6b0 kernel/time/timer.c:1414 expire_timers kernel/time/timer.c:1462 [inline] __run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1731 __run_timers kernel/time/timer.c:1712 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1744 __do_softirq+0x29b/0x9f6 kernel/softirq.c:343 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:226 [inline] __irq_exit_rcu kernel/softirq.c:420 [inline] irq_exit_rcu+0x134/0x200 kernel/softirq.c:432 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:629 RIP: 0010:rcu_lockdep_current_cpu_online kernel/rcu/tree.c:1163 [inline] RIP: 0010:rcu_lockdep_current_cpu_online+0x89/0x150 kernel/rcu/tree.c:1152 Code: 00 00 00 48 03 1c ed c0 f6 e6 8a 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 18 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 90 00 00 00 <48> 8d 7b 20 48 8b 6b 18 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 RSP: 0018:ffffc9000306f228 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffff8880b9c35a80 RCX: ffffffff8158ce61 RDX: 1ffff11017386b53 RSI: 0000000000000002 RDI: ffff8880b9c35a98 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8da38fcf R10: fffffbfff1b471f9 R11: 0000000000000001 R12: 0000000000000001 R13: 0000000000000260 R14: ffffffff86ccf4e0 R15: dffffc0000000000 rcu_read_lock_held_common kernel/rcu/update.c:110 [inline] rcu_read_lock_held_common kernel/rcu/update.c:100 [inline] rcu_read_lock_sched_held+0x25/0x70 kernel/rcu/update.c:121 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x5b7/0x710 kernel/locking/lockdep.c:5453 might_alloc include/linux/sched/mm.h:193 [inline] slab_pre_alloc_hook mm/slab.h:493 [inline] slab_alloc_node mm/slub.c:2817 [inline] slab_alloc mm/slub.c:2900 [inline] kmem_cache_alloc_trace+0x3b/0x360 mm/slub.c:2917 kmalloc include/linux/slab.h:552 [inline] snd_pcm_hw_param_near.constprop.0+0xe0/0x8f0 sound/core/oss/pcm_oss.c:400 snd_pcm_oss_change_params_locked+0x970/0x39a0 sound/core/oss/pcm_oss.c:882 snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1090 [inline] snd_pcm_oss_make_ready+0xe7/0x1b0 sound/core/oss/pcm_oss.c:1149 snd_pcm_oss_set_trigger.isra.0+0x30f/0x6e0 sound/core/oss/pcm_oss.c:2057 snd_pcm_oss_poll+0x661/0xb10 sound/core/oss/pcm_oss.c:2841 vfs_poll include/linux/poll.h:90 [inline] do_select+0x8db/0x1690 fs/select.c:534 core_sys_select+0x3ba/0x9b0 fs/select.c:677 do_pselect.constprop.0+0x17b/0x1c0 fs/select.c:759 __do_sys_pselect6 fs/select.c:800 [inline] __se_sys_pselect6 fs/select.c:791 [inline] __x64_sys_pselect6+0x1c5/0x2b0 fs/select.c:791 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x465b09 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fba2dd5c188 EFLAGS: 00000246 ORIG_RAX: 000000000000010e RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000040 RBP: 00000000004b069f R08: 0000000020000200 R09: 0000000000000000 R10: 0000000020000040 R11: 0000000000000246 R12: 000000000056bf60 R13: 0000000000a9fb1f R14: 00007fba2dd5c300 R15: 0000000000022000 ------------[ cut here ]------------ timer: pie_timer+0x0/0x180 net/sched/sch_pie.c:541 preempt leak: 00000102 -> 00000103 WARNING: CPU: 0 PID: 18365 at kernel/time/timer.c:1423 call_timer_fn+0x5d8/0x6b0 kernel/time/timer.c:1423 Modules linked in: CPU: 0 PID: 18365 Comm: syz-executor.1 Not tainted 5.11.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:call_timer_fn+0x5d8/0x6b0 kernel/time/timer.c:1423 Code: e8 3d 73 10 00 89 da 4c 89 f6 48 c7 c7 40 80 4d 89 65 8b 0d 4a 8e 9f 7e 81 e1 ff ff ff 7f c6 05 5e 0f 2d 0c 01 e8 82 5a 57 07 <0f> 0b e9 80 fc ff ff e8 0c 73 10 00 0f 0b e9 fb fd ff ff e8 00 73 RSP: 0018:ffffc90000007d58 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000102 RCX: 0000000000000000 RDX: ffff888028320000 RSI: ffffffff815b73e5 RDI: fffff52000000f9d RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff815b05be R11: 0000000000000000 R12: 0000000000000000 R13: 1ffff92000000fac R14: ffffffff87283ad0 R15: 0000000000000000 FS: 00007fba2dd5c700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000520230 CR3: 0000000088963000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: expire_timers kernel/time/timer.c:1462 [inline] __run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1731 __run_timers kernel/time/timer.c:1712 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1744 __do_softirq+0x29b/0x9f6 kernel/softirq.c:343 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:226 [inline] __irq_exit_rcu kernel/softirq.c:420 [inline] irq_exit_rcu+0x134/0x200 kernel/softirq.c:432 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:629 RIP: 0010:rcu_lockdep_current_cpu_online kernel/rcu/tree.c:1163 [inline] RIP: 0010:rcu_lockdep_current_cpu_online+0x89/0x150 kernel/rcu/tree.c:1152 Code: 00 00 00 48 03 1c ed c0 f6 e6 8a 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 18 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 90 00 00 00 <48> 8d 7b 20 48 8b 6b 18 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 RSP: 0018:ffffc9000306f228 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffff8880b9c35a80 RCX: ffffffff8158ce61 RDX: 1ffff11017386b53 RSI: 0000000000000002 RDI: ffff8880b9c35a98 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8da38fcf R10: fffffbfff1b471f9 R11: 0000000000000001 R12: 0000000000000001 R13: 0000000000000260 R14: ffffffff86ccf4e0 R15: dffffc0000000000 rcu_read_lock_held_common kernel/rcu/update.c:110 [inline] rcu_read_lock_held_common kernel/rcu/update.c:100 [inline] rcu_read_lock_sched_held+0x25/0x70 kernel/rcu/update.c:121 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x5b7/0x710 kernel/locking/lockdep.c:5453 might_alloc include/linux/sched/mm.h:193 [inline] slab_pre_alloc_hook mm/slab.h:493 [inline] slab_alloc_node mm/slub.c:2817 [inline] slab_alloc mm/slub.c:2900 [inline] kmem_cache_alloc_trace+0x3b/0x360 mm/slub.c:2917 kmalloc include/linux/slab.h:552 [inline] snd_pcm_hw_param_near.constprop.0+0xe0/0x8f0 sound/core/oss/pcm_oss.c:400 snd_pcm_oss_change_params_locked+0x970/0x39a0 sound/core/oss/pcm_oss.c:882 snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1090 [inline] snd_pcm_oss_make_ready+0xe7/0x1b0 sound/core/oss/pcm_oss.c:1149 snd_pcm_oss_set_trigger.isra.0+0x30f/0x6e0 sound/core/oss/pcm_oss.c:2057 snd_pcm_oss_poll+0x661/0xb10 sound/core/oss/pcm_oss.c:2841 vfs_poll include/linux/poll.h:90 [inline] do_select+0x8db/0x1690 fs/select.c:534 core_sys_select+0x3ba/0x9b0 fs/select.c:677 do_pselect.constprop.0+0x17b/0x1c0 fs/select.c:759 __do_sys_pselect6 fs/select.c:800 [inline] __se_sys_pselect6 fs/select.c:791 [inline] __x64_sys_pselect6+0x1c5/0x2b0 fs/select.c:791 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x465b09 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fba2dd5c188 EFLAGS: 00000246 ORIG_RAX: 000000000000010e RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000040 RBP: 00000000004b069f R08: 0000000020000200 R09: 0000000000000000 R10: 0000000020000040 R11: 0000000000000246 R12: 000000000056bf60 R13: 0000000000a9fb1f R14: 00007fba2dd5c300 R15: 0000000000022000