rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=b774/1/0x4000000000000000 softirq=48446/48447 fqs=1 rcu: (detected by 1, t=10505 jiffies, g=34929, q=489 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 13847 Comm: syz.1.1077 Not tainted 6.13.0-rc4-syzkaller-00012-g9b2ffa6148b1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:hlock_class+0x56/0x130 kernel/locking/lockdep.c:228 Code: 20 66 81 e3 ff 1f 0f b7 db be 08 00 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 c0 1c e5 96 e8 c2 f7 86 00 48 0f a3 1d 7a 4b 6f 15 <73> 13 48 69 c3 c8 00 00 00 5b 48 05 e0 20 e5 96 c3 cc cc cc cc 48 RSP: 0018:ffffc90000007b28 EFLAGS: 00000047 RAX: 0000000000000001 RBX: 0000000000000ac6 RCX: ffffffff8175d13e RDX: fffffbfff2dca3c4 RSI: 0000000000000008 RDI: ffffffff96e51e18 RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff2dca3c3 R10: ffffffff96e51e1f R11: 0000000000000001 R12: 0000000000000002 R13: ffff88807c0b0000 R14: 0000000000000ac6 R15: ffff88807c0b0ae0 FS: 00007f77705d56c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffff CR3: 00000000593ce000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000097 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: check_wait_context kernel/locking/lockdep.c:4850 [inline] __lock_acquire+0x410/0x3c40 kernel/locking/lockdep.c:5176 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] advance_sched+0xd8/0xc60 net/sched/sch_taprio.c:924 __run_hrtimer kernel/time/hrtimer.c:1739 [inline] __hrtimer_run_queues+0x20a/0xae0 kernel/time/hrtimer.c:1803 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1865 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_release+0x3e5/0x6f0 kernel/locking/lockdep.c:5857 Code: 7e 83 f8 01 0f 85 fe 01 00 00 9c 58 f6 c4 02 0f 85 e9 01 00 00 48 f7 04 24 00 02 00 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 c7 43 08 00 00 00 00 48 8b 84 24 88 RSP: 0018:ffffc9000438f660 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff92000871ece RCX: ffffc9000438f6b0 RDX: 1ffff1100f81615a RSI: ffffffff8b6cdce0 RDI: ffffffff8bd1ed60 RBP: ffffffffffffffff R08: 0000000000000000 R09: fffffbfff20be6aa R10: ffffffff905f3557 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000001 R14: ffff88807c0b0ad8 R15: ffff88807c0b0000 __mutex_unlock_slowpath+0xa3/0x690 kernel/locking/mutex.c:896 __unix_dgram_recvmsg+0x829/0xe50 net/unix/af_unix.c:2522 unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2538 sock_recvmsg_nosec net/socket.c:1033 [inline] ____sys_recvmsg+0x5f8/0x6b0 net/socket.c:2801 ___sys_recvmsg+0x115/0x1a0 net/socket.c:2845 do_recvmmsg+0x2f8/0x740 net/socket.c:2940 __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+0x239/0x290 net/socket.c:3030 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7772785d29 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:00007f77705d5038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f7772976080 RCX: 00007f7772785d29 RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000008 RBP: 00007f7772801aa8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f7772976080 R15: 00007ffe5b1de8b8 rcu: rcu_preempt kthread starved for 10500 jiffies! g34929 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:27600 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6848 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2045 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2247 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 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: 6282 Comm: kworker/u8:12 Not tainted 6.13.0-rc4-syzkaller-00012-g9b2ffa6148b1 #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+0x458/0x1300 kernel/smp.c:884 Code: 0c 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 ba 0e 0c 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 a7 0c 00 00 8b 43 08 31 RSP: 0018:ffffc90003077998 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b86469c0 RCX: ffffffff818e071c RDX: ffff888036154880 RSI: ffffffff818e06f6 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000006 R12: ffffed10170c8d39 R13: 0000000000000001 R14: ffff8880b86469c8 R15: ffff8880b873fe40 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fea4d43aaa2 CR3: 000000000df7e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000097 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 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+0x22b/0x760 arch/x86/kernel/alternative.c:2324 text_poke_flush arch/x86/kernel/alternative.c:2515 [inline] text_poke_flush arch/x86/kernel/alternative.c:2512 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2522 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d7/0x400 kernel/jump_label.c:920 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate mm/kfence/core.c:849 [inline] toggle_allocation_gate+0xfc/0x260 mm/kfence/core.c:841 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244