rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=1afc/1/0x4000000000000000 softirq=72991/72992 fqs=2 rcu: (detected by 1, t=10502 jiffies, g=76921, q=216 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 16705 Comm: syz.8.2943 Not tainted 6.13.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:timerqueue_del+0xb1/0x100 lib/timerqueue.c:58 Code: ff ff 41 80 3c 2f 00 74 0e 48 89 df 49 89 c7 e8 f5 57 47 f6 4c 89 f8 48 89 03 4c 89 ef 4c 89 f6 e8 94 6d ff ff 41 80 3c 2c 00 <74> 08 4c 89 ef e8 d5 57 47 f6 4d 89 6d 00 4c 89 f0 48 c1 e8 03 80 RSP: 0018:ffffc90000007d08 EFLAGS: 00000046 RAX: 1ffff110170c593a RBX: ffff8880b862c9d8 RCX: dffffc0000000000 RDX: 0000000000010000 RSI: ffff8880b862c9d0 RDI: ffff88805f172348 RBP: dffffc0000000000 R08: ffffffff8bbbdaf8 R09: 1ffffffff203075e R10: dffffc0000000000 R11: fffffbfff203075f R12: 1ffff1100be2e468 R13: ffff88805f172340 R14: ffff8880b862c9d0 R15: 1ffff110170c593b FS: 00007fc49321e6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb7bb01ffb8 CR3: 0000000033c42000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __remove_hrtimer kernel/time/hrtimer.c:1109 [inline] __run_hrtimer kernel/time/hrtimer.c:1719 [inline] __hrtimer_run_queues+0x3d0/0xd30 kernel/time/hrtimer.c:1803 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1865 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:check_preemption_disabled+0x42/0x120 lib/smp_processor_id.c:55 Code: 08 65 8b 1d 1c 8d 43 74 65 8b 05 11 8d 43 74 a9 ff ff ff 7f 74 26 65 48 8b 04 25 28 00 00 00 48 3b 44 24 08 0f 85 ce 00 00 00 <89> d8 48 83 c4 10 5b 41 5c 41 5e 41 5f c3 cc cc cc cc 48 c7 04 24 RSP: 0018:ffffc9000df9f888 EFLAGS: 00000246 RAX: 42d91bd70c866f00 RBX: 0000000000000000 RCX: ffffffff817a9934 RDX: 0000000000000000 RSI: ffffffff8c5ec220 RDI: ffffffff8c5ec1e0 RBP: ffffc9000df9fa38 R08: ffffffff90183af7 R09: 1ffffffff203075e R10: dffffc0000000000 R11: fffffbfff203075f R12: 1ffff92001bf3f24 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff110039f20a9 rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:737 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0xe3/0x550 kernel/locking/lockdep.c:5820 __might_fault+0xc6/0x120 mm/memory.c:6751 do_recvmmsg+0x59c/0xab0 net/socket.c:2946 __sys_recvmmsg net/socket.c:3014 [inline] __do_sys_recvmmsg net/socket.c:3037 [inline] __se_sys_recvmmsg net/socket.c:3030 [inline] __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3030 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc49237fed9 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc49321e058 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fc492546080 RCX: 00007fc49237fed9 RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000006 RBP: 00007fc4923f3cc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fc492546080 R15: 00007ffe1b138cd8 rcu: rcu_preempt kthread starved for 10498 jiffies! g76921 f0x0 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:25976 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 11631 Comm: kworker/u8:12 Not tainted 6.13.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x1a04/0x2c60 kernel/smp.c:884 Code: 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 01 e5 0b 00 eb 38 f3 90 42 0f b6 04 23 84 c0 75 11 41 f7 45 00 01 00 00 00 <74> 1e e8 e5 e4 0b 00 eb e4 44 89 e9 80 e1 07 80 c1 03 38 c1 7c e2 RSP: 0018:ffffc9000459f6e0 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 1ffff110170c8c65 RCX: ffff888035529e00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000459f8e0 R08: ffffffff819378da R09: 1ffffffff284db10 R10: dffffc0000000000 R11: fffffbfff284db11 R12: dffffc0000000000 R13: ffff8880b8646328 R14: ffff8880b873f940 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5701d0f338 CR3: 000000000e736000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1051 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2114 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2324 text_poke_flush arch/x86/kernel/alternative.c:2515 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2522 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xbc/0x260 mm/kfence/core.c:849 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244