rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=10581, q=1097) rcu: All QSes seen, last rcu_preempt kthread activity 10434 (4295007965-4294997531), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10434 jiffies! g10581 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:29176 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-rc6-syzkaller #0 Not tainted -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. syz-executor.1/9949 [HC0[0]:SC1[1]:HE0:SE0] takes: ffffffff8b37c058 (rcu_node_0){?.-.}-{2:2}, at: print_other_cpu_stall kernel/rcu/tree_stall.h:493 [inline] ffffffff8b37c058 (rcu_node_0){?.-.}-{2:2}, at: check_cpu_stall kernel/rcu/tree_stall.h:652 [inline] ffffffff8b37c058 (rcu_node_0){?.-.}-{2:2}, at: rcu_pending kernel/rcu/tree.c:3751 [inline] ffffffff8b37c058 (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 __kasan_check_write+0x4/0x10 mm/kasan/shadow.c:36 instrument_atomic_write include/linux/instrumented.h:86 [inline] atomic_set include/asm-generic/atomic-instrumented.h:45 [inline] set_page_count include/linux/page_ref.h:77 [inline] prep_compound_page+0xb1/0x460 mm/page_alloc.c:679 prep_new_page mm/page_alloc.c:2309 [inline] get_page_from_freelist+0x3355/0x3f80 mm/page_alloc.c:3945 __alloc_pages_nodemask+0x2d6/0x730 mm/page_alloc.c:4995 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:2857 [inline] slab_alloc mm/slub.c:2900 [inline] kmem_cache_alloc+0x36e/0x440 mm/slub.c:2905 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: 13658553 hardirqs last enabled at (13658552): [] asm_sysvec_irq_work+0x12/0x20 arch/x86/include/asm/idtentry.h:655 hardirqs last disabled at (13658553): [] sysvec_apic_timer_interrupt+0xc/0x100 arch/x86/kernel/apic/apic.c:1096 softirqs last enabled at (12151776): [] asm_call_irq_on_stack+0xf/0x20 softirqs last disabled at (12151779): [] 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 *** 3 locks held by syz-executor.1/9949: #0: ffffffff8b373da0 (rcu_read_lock){....}-{1:2}, at: ieee80211_iterate_active_interfaces_atomic+0x0/0x170 net/mac80211/util.c:1299 #1: ffffffff8b373da0 (rcu_read_lock){....}-{1:2}, at: __ieee80211_beacon_get+0x0/0x1aa0 net/mac80211/tx.c:4546 #2: ffffffff8b37c058 (rcu_node_0){?.-.}-{2:2}, at: print_other_cpu_stall kernel/rcu/tree_stall.h:493 [inline] #2: ffffffff8b37c058 (rcu_node_0){?.-.}-{2:2}, at: check_cpu_stall kernel/rcu/tree_stall.h:652 [inline] #2: ffffffff8b37c058 (rcu_node_0){?.-.}-{2:2}, at: rcu_pending kernel/rcu/tree.c:3751 [inline] #2: ffffffff8b37c058 (rcu_node_0){?.-.}-{2:2}, at: rcu_sched_clock_irq.cold+0xbc/0xedf kernel/rcu/tree.c:2580 stack backtrace: CPU: 0 PID: 9949 Comm: syz-executor.1 Not tainted 5.11.0-rc6-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:unwind_next_frame+0x367/0x1f90 arch/x86/kernel/unwind_orc.c:456 Code: e8 7e f5 ff ff 49 89 c0 4d 85 c0 0f 84 56 02 00 00 4d 8d 48 04 48 b8 00 00 00 00 00 fc ff df 4c 89 ca 48 c1 ea 03 0f b6 04 02 <4c> 89 ca 83 e2 07 38 d0 7f 08 84 c0 0f 85 6f 08 00 00 41 0f b6 40 RSP: 0018:ffffc90000007690 EFLAGS: 00000213 RAX: 0000000000000000 RBX: 1ffff92000000eda RCX: ffffffff8162bcf8 RDX: 1ffffffff1afcba4 RSI: ffffffff8d7e5d20 RDI: ffffffff8d12829c RBP: 0000000000000002 R08: ffffffff8d7e5d20 R09: ffffffff8d7e5d24 R10: 0000000000082083 R11: 00000000000178ac R12: ffffc900000077b0 R13: ffffc9000000779d R14: ffffc900000077b8 R15: ffffc90000007768 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:209 [inline] slab_post_alloc_hook mm/slab.h:512 [inline] slab_alloc_node mm/slub.c:2892 [inline] kmem_cache_alloc_node+0x1e0/0x470 mm/slub.c:2928 __alloc_skb+0x71/0x5a0 net/core/skbuff.c:198 __netdev_alloc_skb+0x70/0x400 net/core/skbuff.c:446 netdev_alloc_skb include/linux/skbuff.h:2832 [inline] dev_alloc_skb include/linux/skbuff.h:2845 [inline] __ieee80211_beacon_get+0xebe/0x1aa0 net/mac80211/tx.c:4814 ieee80211_beacon_get_tim+0x88/0x910 net/mac80211/tx.c:4928 ieee80211_beacon_get include/net/mac80211.h:4918 [inline] mac80211_hwsim_beacon_tx+0x111/0x910 drivers/net/wireless/mac80211_hwsim.c:1729 __iterate_interfaces+0x1e5/0x520 net/mac80211/util.c:793 ieee80211_iterate_active_interfaces_atomic+0x8d/0x170 net/mac80211/util.c:829 mac80211_hwsim_beacon+0xd5/0x1a0 drivers/net/wireless/mac80211_hwsim.c:1782 __run_hrtimer kernel/time/hrtimer.c:1519 [inline] __hrtimer_run_queues+0x609/0xe40 kernel/time/hrtimer.c:1583 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1600 __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:1096 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:629 RIP: 0010:preempt_schedule_irq+0x49/0x90 kernel/sched/core.c:5340 Code: 55 53 65 48 8b 1c 25 00 f0 01 00 48 89 dd 48 c1 ed 03 48 01 c5 bf 01 00 00 00 e8 f2 22 52 f8 e8 4d 27 7d f8 fb bf 01 00 00 00 02 d1 ff ff 9c 58 fa f6 c4 02 75 27 bf 01 00 00 00 e8 00 11 52 RSP: 0018:ffffc9000b2b7e48 EFLAGS: 00000206 RAX: 00000000000000a5 RBX: ffff888023409bc0 RCX: 1ffffffff1a06a11 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffed1004681378 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff81788e28 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 irqentry_exit_cond_resched kernel/entry/common.c:393 [inline] irqentry_exit_cond_resched kernel/entry/common.c:385 [inline] irqentry_exit+0x7a/0xa0 kernel/entry/common.c:423 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:629 RIP: 0010:__x64_sys_futex+0xb2/0x1b0 kernel/futex.c:3765 Code: c1 ea 03 80 3c 02 00 0f 85 be 00 00 00 48 8d 7b 68 48 8b 53 60 48 b8 00 00 00 00 00 fc ff df 48 89 fe 48 c1 ee 03 80 3c 06 00 <75> 6f 48 8d 7b 70 48 8b 73 68 48 b8 00 00 00 00 00 fc ff df 49 89 RSP: 0018:ffffc9000b2b7f10 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffffc9000b2b7f58 RCX: 0000000000000000 RDX: 00000000000f4240 RSI: 1ffff92001656ff8 RDI: ffffc9000b2b7fc0 RBP: ffffc9000b2b7f58 R08: 000000000000000e R09: 0000000000000000 R10: ffffffff81788e28 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 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:00007fdd020cc218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 000000000056bf68 RCX: 0000000000465b09 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 000000000056bf6c RBP: 000000000056bf60 R08: 000000000000000e R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf6c R13: 00007ffe8f23d80f R14: 00007fdd020cc300 R15: 0000000000022000