rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=290317, q=249) rcu: All QSes seen, last rcu_preempt kthread activity 10481 (4295164774-4295154293), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10482 jiffies! g290317 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:29080 pid: 13 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4313 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5064 schedule+0xcf/0x270 kernel/sched/core.c:5143 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-rc2-syzkaller #0 Not tainted -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. syz-executor.5/7936 [HC0[0]:SC1[1]:HE0:SE0] takes: ffffffff8b37bbd8 (rcu_node_0){?.-.}-{2:2}, at: print_other_cpu_stall kernel/rcu/tree_stall.h:493 [inline] ffffffff8b37bbd8 (rcu_node_0){?.-.}-{2:2}, at: check_cpu_stall kernel/rcu/tree_stall.h:652 [inline] ffffffff8b37bbd8 (rcu_node_0){?.-.}-{2:2}, at: rcu_pending kernel/rcu/tree.c:3751 [inline] ffffffff8b37bbd8 (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:5437 [inline] lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402 __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:636 native_restore_fl arch/x86/include/asm/irqflags.h:41 [inline] arch_local_irq_restore arch/x86/include/asm/irqflags.h:84 [inline] seqcount_lockdep_reader_access include/linux/seqlock.h:105 [inline] read_seqbegin include/linux/seqlock.h:843 [inline] zone_span_seqbegin include/linux/memory_hotplug.h:93 [inline] page_outside_zone_boundaries mm/page_alloc.c:568 [inline] bad_range+0xc2/0x310 mm/page_alloc.c:597 rmqueue mm/page_alloc.c:3520 [inline] get_page_from_freelist+0x1c90/0x4160 mm/page_alloc.c:3939 __alloc_pages_nodemask+0x2d6/0x730 mm/page_alloc.c:4992 alloc_pages_current+0x18c/0x2a0 mm/mempolicy.c:2267 alloc_pages include/linux/gfp.h:547 [inline] alloc_slab_page mm/slub.c:1618 [inline] allocate_slab+0x2b6/0x4a0 mm/slub.c:1758 new_slab mm/slub.c:1821 [inline] new_slab_objects mm/slub.c:2578 [inline] ___slab_alloc+0x476/0x790 mm/slub.c:2741 __slab_alloc.constprop.0+0x95/0xe0 mm/slub.c:2781 slab_alloc_node mm/slub.c:2856 [inline] slab_alloc mm/slub.c:2899 [inline] kmem_cache_alloc+0x36e/0x440 mm/slub.c:2904 getname_kernel+0x4e/0x370 fs/namei.c:218 kernel_execve+0x24/0x460 fs/exec.c:1932 call_usermodehelper_exec_async+0x2de/0x580 kernel/umh.c:110 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 irq event stamp: 13202049 hardirqs last enabled at (13202048): [] asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628 hardirqs last disabled at (13202049): [] sysvec_apic_timer_interrupt+0xc/0x100 arch/x86/kernel/apic/apic.c:1096 softirqs last enabled at (4505298): [] asm_call_irq_on_stack+0xf/0x20 softirqs last disabled at (4505511): [] 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.5/7936: #0: ffff888079fb7440 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1087 [inline] #0: ffff888079fb7440 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_make_ready+0xc7/0x1b0 sound/core/oss/pcm_oss.c:1149 #1: ffffffff8b4a80d8 (remove_cache_srcu){....}-{0:0}, at: quarantine_reduce+0x41/0x200 mm/kasan/quarantine.c:274 #2: ffffc90000db0d78 ((&app->join_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:35 [inline] #2: ffffc90000db0d78 ((&app->join_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 kernel/time/timer.c:1407 #3: ffff88806b8458c8 (&app->lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:354 [inline] #3: ffff88806b8458c8 (&app->lock){+.-.}-{2:2}, at: mrp_join_timer+0x23/0xc0 net/802/mrp.c:590 #4: ffffffff8b37bbd8 (rcu_node_0){?.-.}-{2:2}, at: print_other_cpu_stall kernel/rcu/tree_stall.h:493 [inline] #4: ffffffff8b37bbd8 (rcu_node_0){?.-.}-{2:2}, at: check_cpu_stall kernel/rcu/tree_stall.h:652 [inline] #4: ffffffff8b37bbd8 (rcu_node_0){?.-.}-{2:2}, at: rcu_pending kernel/rcu/tree.c:3751 [inline] #4: ffffffff8b37bbd8 (rcu_node_0){?.-.}-{2:2}, at: rcu_sched_clock_irq.cold+0xbc/0xedf kernel/rcu/tree.c:2580 stack backtrace: CPU: 1 PID: 7936 Comm: syz-executor.5 Not tainted 5.11.0-rc2-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:628 RIP: 0010:__orc_find+0x8b/0xf0 arch/x86/kernel/unwind_orc.c:56 Code: 85 00 48 89 d8 48 c1 e8 03 42 0f b6 14 38 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 48 48 63 03 48 01 d8 48 39 c1 73 b0 <4c> 8d 63 fc 49 39 ec 73 b3 4d 29 ee 49 c1 fe 02 4b 8d 04 76 48 8d RSP: 0018:ffffc90000db0728 EFLAGS: 00000293 RAX: ffffffff81b56a66 RBX: ffffffff8d1714cc RCX: ffffffff81b56a61 RDX: 0000000000000000 RSI: ffffffff8d853cd8 RDI: ffffffff8d1714c8 RBP: ffffffff8d1714c8 R08: ffffffff8d853d50 R09: ffffffff8d853cd8 R10: 0000000000082083 R11: 000000000002a2ac R12: ffffffff8d1714d4 R13: ffffffff8d1714c8 R14: ffffffff8d1714c8 R15: dffffc0000000000 orc_find arch/x86/kernel/unwind_orc.c:173 [inline] unwind_next_frame+0x342/0x1f90 arch/x86/kernel/unwind_orc.c:443 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 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:205 [inline] slab_post_alloc_hook mm/slab.h:512 [inline] slab_alloc_node mm/slub.c:2891 [inline] kmem_cache_alloc_node+0x1e0/0x470 mm/slub.c:2927 __alloc_skb+0x71/0x5a0 net/core/skbuff.c:198 alloc_skb include/linux/skbuff.h:1099 [inline] mrp_pdu_init net/802/mrp.c:300 [inline] mrp_pdu_append_vecattr_event+0x7b4/0x1020 net/802/mrp.c:399 mrp_attr_event+0x191/0x280 net/802/mrp.c:494 mrp_mad_event net/802/mrp.c:574 [inline] mrp_join_timer+0x5a/0xc0 net/802/mrp.c:591 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1417 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+0x2bc/0xa29 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:1096 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628 RIP: 0010:native_restore_fl arch/x86/include/asm/irqflags.h:41 [inline] RIP: 0010:arch_local_irq_restore arch/x86/include/asm/irqflags.h:84 [inline] RIP: 0010:put_cpu_partial+0x79/0x200 mm/slub.c:2396 Code: 8b 2c 24 e8 a9 2b 44 07 83 f8 07 41 89 c7 0f 87 4a 01 00 00 4a 8b 34 fd c0 b6 e6 8a 4c 89 e7 4c 01 ee e8 da fd ff ff 41 56 9d <31> c0 89 de 31 ff 31 c9 0f b7 55 2a 89 75 10 44 0f b7 45 28 48 89 RSP: 0018:ffffc9001892f8f8 EFLAGS: 00000297 RAX: 000000000044bfa5 RBX: 0000000000000001 RCX: ffffffff81584837 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffea0002627800 R08: 0000000000000001 R09: ffffffff8ed308e7 R10: fffffbfff1da611c R11: 0000000000000009 R12: ffff888010042140 R13: 00000000000385f0 R14: 0000000000000297 R15: 0000000000000001 qlink_free mm/kasan/quarantine.c:146 [inline] qlist_free_all+0x5a/0xc0 mm/kasan/quarantine.c:165 quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272 ____kasan_kmalloc.constprop.0+0x98/0xa0 mm/kasan/common.c:412 kasan_slab_alloc include/linux/kasan.h:205 [inline] slab_post_alloc_hook mm/slab.h:512 [inline] slab_alloc_node mm/slub.c:2891 [inline] slab_alloc mm/slub.c:2899 [inline] __kmalloc+0x1db/0x3e0 mm/slub.c:3966 kmalloc_array include/linux/slab.h:592 [inline] kcalloc include/linux/slab.h:621 [inline] snd_pcm_plugin_build+0x436/0x700 sound/core/oss/pcm_plugin.c:177 snd_pcm_plugin_build_mulaw+0x278/0x7d0 sound/core/oss/mulaw.c:335 snd_pcm_plug_format_plugins+0xb76/0x1360 sound/core/oss/pcm_plugin.c:494 snd_pcm_oss_change_params_locked+0x2e60/0x39a0 sound/core/oss/pcm_oss.c:958 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_sync+0x1de/0x800 sound/core/oss/pcm_oss.c:1714 snd_pcm_oss_release+0x276/0x300 sound/core/oss/pcm_oss.c:2556 __fput+0x283/0x920 fs/file_table.c:280 task_work_run+0xdd/0x190 kernel/task_work.c:140 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e219 Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd1ae387c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffea RBX: 0000000000000004 RCX: 000000000045e219 RDX: 000000000000c280 RSI: 0000000020000000 RDI: ffffffffffffff9c RBP: 000000000119bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00000000016afb5f R14: 00007fd1ae3889c0 R15: 000000000119bf8c ------------[ cut here ]------------ timer: mrp_join_timer+0x0/0xc0 net/802/mrp.c:483 preempt leak: 00000101 -> 00000102 WARNING: CPU: 1 PID: 7936 at kernel/time/timer.c:1423 call_timer_fn+0x5d8/0x6b0 kernel/time/timer.c:1423 Modules linked in: CPU: 1 PID: 7936 Comm: syz-executor.5 Not tainted 5.11.0-rc2-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 6d 75 10 00 89 da 4c 89 f6 48 c7 c7 60 7f 4d 89 65 8b 0d 9a 9c 9f 7e 81 e1 ff ff ff 7f c6 05 88 04 8d 0b 01 e8 5c 0b 56 07 <0f> 0b e9 80 fc ff ff e8 3c 75 10 00 0f 0b e9 fb fd ff ff e8 30 75 RSP: 0018:ffffc90000db0d40 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000101 RCX: 0000000000000000 RDX: ffff888072360000 RSI: ffffffff815b69d5 RDI: fffff520001b619a RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff815afbae R11: 0000000000000000 R12: 0000000000000000 R13: 1ffff920001b61a9 R14: ffffffff87120610 R15: 0000000000000000 FS: 00007fd1ae388700(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004fc8f0 CR3: 000000009a407000 CR4: 00000000001506e0 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+0x2bc/0xa29 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:1096 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628 RIP: 0010:native_restore_fl arch/x86/include/asm/irqflags.h:41 [inline] RIP: 0010:arch_local_irq_restore arch/x86/include/asm/irqflags.h:84 [inline] RIP: 0010:put_cpu_partial+0x79/0x200 mm/slub.c:2396 Code: 8b 2c 24 e8 a9 2b 44 07 83 f8 07 41 89 c7 0f 87 4a 01 00 00 4a 8b 34 fd c0 b6 e6 8a 4c 89 e7 4c 01 ee e8 da fd ff ff 41 56 9d <31> c0 89 de 31 ff 31 c9 0f b7 55 2a 89 75 10 44 0f b7 45 28 48 89 RSP: 0018:ffffc9001892f8f8 EFLAGS: 00000297 RAX: 000000000044bfa5 RBX: 0000000000000001 RCX: ffffffff81584837 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffea0002627800 R08: 0000000000000001 R09: ffffffff8ed308e7 R10: fffffbfff1da611c R11: 0000000000000009 R12: ffff888010042140 R13: 00000000000385f0 R14: 0000000000000297 R15: 0000000000000001 qlink_free mm/kasan/quarantine.c:146 [inline] qlist_free_all+0x5a/0xc0 mm/kasan/quarantine.c:165 quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272 ____kasan_kmalloc.constprop.0+0x98/0xa0 mm/kasan/common.c:412 kasan_slab_alloc include/linux/kasan.h:205 [inline] slab_post_alloc_hook mm/slab.h:512 [inline] slab_alloc_node mm/slub.c:2891 [inline] slab_alloc mm/slub.c:2899 [inline] __kmalloc+0x1db/0x3e0 mm/slub.c:3966 kmalloc_array include/linux/slab.h:592 [inline] kcalloc include/linux/slab.h:621 [inline] snd_pcm_plugin_build+0x436/0x700 sound/core/oss/pcm_plugin.c:177 snd_pcm_plugin_build_mulaw+0x278/0x7d0 sound/core/oss/mulaw.c:335 snd_pcm_plug_format_plugins+0xb76/0x1360 sound/core/oss/pcm_plugin.c:494 snd_pcm_oss_change_params_locked+0x2e60/0x39a0 sound/core/oss/pcm_oss.c:958 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_sync+0x1de/0x800 sound/core/oss/pcm_oss.c:1714 snd_pcm_oss_release+0x276/0x300 sound/core/oss/pcm_oss.c:2556 __fput+0x283/0x920 fs/file_table.c:280 task_work_run+0xdd/0x190 kernel/task_work.c:140 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e219 Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd1ae387c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffea RBX: 0000000000000004 RCX: 000000000045e219 RDX: 000000000000c280 RSI: 0000000020000000 RDI: ffffffffffffff9c RBP: 000000000119bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00000000016afb5f R14: 00007fd1ae3889c0 R15: 000000000119bf8c