rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=5b84/1/0x4000000000000000 softirq=23576/23577 fqs=1 rcu: (detected by 1, t=10502 jiffies, g=13113, q=490 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 7053 Comm: syz.5.281 Not tainted 6.12.0-syzkaller-11677-g2ba9f676d0a2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:lock_acquire+0x104/0x550 kernel/locking/lockdep.c:5822 Code: ab 0e 73 16 e8 ed 5f 0a 00 84 c0 75 0d 80 3d 06 8b 95 0e 00 0f 84 f9 02 00 00 48 c7 c0 40 a3 1c 90 48 c1 e8 03 42 0f b6 04 28 <84> c0 0f 85 ff 02 00 00 83 3d fd 87 ab 0e 00 0f 84 42 01 00 00 65 RSP: 0018:ffffc90000007a20 EFLAGS: 00000802 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81711b04 RDX: 0000000000000000 RSI: ffffffff8c608440 RDI: ffffffff8c608400 RBP: ffffc90000007b68 R08: ffffffff901c70b7 R09: 1ffffffff2038e16 R10: dffffc0000000000 R11: fffffbfff2038e17 R12: 1ffff92000000f4c R13: dffffc0000000000 R14: 0000000000000000 R15: dffffc0000000000 FS: 00007f869b5c26c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7fbef56018 CR3: 000000005fd08000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 debug_object_deactivate+0x158/0x390 lib/debugobjects.c:873 debug_hrtimer_deactivate kernel/time/hrtimer.c:433 [inline] debug_deactivate+0x1b/0x220 kernel/time/hrtimer.c:475 __run_hrtimer kernel/time/hrtimer.c:1707 [inline] __hrtimer_run_queues+0x305/0xd30 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:kasan_check_range+0x1b7/0x290 mm/kasan/generic.c:189 Code: f5 4d 01 fb 48 8d 5d 07 48 85 ed 48 0f 49 dd 48 83 e3 f8 48 29 dd 74 12 41 80 3b 00 0f 85 a6 00 00 00 49 ff c3 48 ff cd 75 ee <5b> 41 5c 41 5e 41 5f 5d c3 cc cc cc cc 40 84 ed 75 5f f7 c5 00 ff RSP: 0018:ffffc900048b7908 EFLAGS: 00000256 RAX: 0000000000000001 RBX: 1ffff92000916f38 RCX: ffffffff84b835ae RDX: 0000000000000001 RSI: 0000000000000038 RDI: ffffc900048b79c0 RBP: 0000000000000000 R08: ffffc900048b79f7 R09: 1ffff92000916f3e R10: dffffc0000000000 R11: fffff52000916f3f R12: 00000000200a5900 R13: dffffc0000000000 R14: dffffc0000000001 R15: fffff52000916f3f instrument_copy_from_user_before include/linux/instrumented.h:129 [inline] _inline_copy_from_user include/linux/uaccess.h:177 [inline] _copy_from_user+0x6e/0xc0 lib/usercopy.c:18 copy_from_user include/linux/uaccess.h:212 [inline] copy_msghdr_from_user+0xae/0x680 net/socket.c:2513 recvmsg_copy_msghdr net/socket.c:2769 [inline] ___sys_recvmsg net/socket.c:2841 [inline] do_recvmmsg+0x3bd/0xab0 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+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: 0033:0x7f869a780849 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:00007f869b5c2058 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f869a946080 RCX: 00007f869a780849 RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000004 RBP: 00007f869a7f3986 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f869a946080 R15: 00007fff0c4073b8 rcu: rcu_preempt kthread starved for 10500 jiffies! g13113 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:26264 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: 12 Comm: kworker/u8:1 Not tainted 6.12.0-syzkaller-11677-g2ba9f676d0a2 #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+0x19f8/0x2c60 kernel/smp.c:884 Code: 89 e6 83 e6 01 31 ff e8 66 e9 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 11 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 f5 e4 0b 00 eb e4 44 RSP: 0018:ffffc900001176e0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff110170c8c65 RCX: ffff88801bee5a00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900001178e0 R08: ffffffff8189fc1a R09: 1ffffffff2038e16 R10: dffffc0000000000 R11: fffffbfff2038e17 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: 00007fb470347bac CR3: 000000000e738000 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