rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 ticks this GP) idle=bfc4/1/0x4000000000000000 softirq=20850/20850 fqs=4 rcu: (detected by 0, t=10502 jiffies, g=14785, q=370 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 7883 Comm: syz.3.884 Not tainted 6.13.0-syzkaller-07259-g0f8e26b38d7a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:rcu_read_lock include/linux/rcupdate.h:850 [inline] RIP: 0010:advance_sched+0x90f/0xc60 net/sched/sch_taprio.c:985 Code: ff e8 85 b3 50 f8 48 c7 c2 a0 66 a3 8c be 6e 03 00 00 48 c7 c7 00 66 a3 8c c6 05 7a a1 e1 06 01 e8 e6 02 2d f8 e9 b0 fd ff ff 5c b3 50 f8 e8 57 80 36 f8 31 ff 89 c3 89 c6 e8 ec ad 50 f8 84 RSP: 0018:ffffc90000a18d80 EFLAGS: 00000002 RAX: ffffffff896901b9 RBX: 0000000000000001 RCX: ffffffff896901cf RDX: ffff88805b0b8000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: ffff8880369ae010 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000002 R13: ffff8880369ae000 R14: ffff888148393340 R15: ffff8880369af800 FS: 00007ff47c1c76c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020006680 CR3: 0000000027260000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1738 [inline] __hrtimer_run_queues+0x20a/0xae0 kernel/time/hrtimer.c:1802 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1864 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 96 ba 3e f6 48 89 df e8 ee 39 3f f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 35 10 30 f6 65 8b 05 96 f2 ab 74 85 c0 74 16 5b RSP: 0018:ffffc9000e4b7ca8 EFLAGS: 00000246 RAX: 0000000000000006 RBX: ffff8880b862c680 RCX: 1ffffffff2dd7073 RDX: 0000000000000000 RSI: ffffffff8b6cda40 RDI: ffffffff8bd2e9c0 RBP: 0000000000000282 R08: 0000000000000001 R09: fffffbfff2dd6f98 R10: ffffffff96eb7cc7 R11: 0000000000000001 R12: 0000000000000004 R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000 clock_was_set+0x591/0x850 kernel/time/hrtimer.c:959 do_settimeofday64+0x305/0x4c0 kernel/time/timekeeping.c:1381 do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195 __do_sys_clock_settime kernel/time/posix-timers.c:1135 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1119 [inline] __x64_sys_clock_settime+0x1bf/0x2a0 kernel/time/posix-timers.c:1119 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: 0033:0x7ff47b38cd29 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:00007ff47c1c7038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007ff47b5a5fa0 RCX: 00007ff47b38cd29 RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000000 RBP: 00007ff47b40e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff47b5a5fa0 R15: 00007ffc9492a4c8 rcu: rcu_preempt kthread starved for 10494 jiffies! g14785 f0x0 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:28280 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0x1142/0x5b60 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6856 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2024 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2226 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 7909 Comm: syz.4.896 Not tainted 6.13.0-syzkaller-07259-g0f8e26b38d7a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x4c6/0x12c0 kernel/smp.c:885 Code: 0c 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 fc 4c 89 fd 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 fc 04 0c 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 e8 0b 00 00 8b 43 08 31 RSP: 0018:ffffc9000e60f438 EFLAGS: 00000246 RAX: 0000000000080000 RBX: ffff8880b8744a00 RCX: ffffc9000cb89000 RDX: 0000000000080000 RSI: ffffffff81adb2b4 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000005 R12: ffffed10170e8941 R13: 0000000000000001 R14: ffff8880b863fe00 R15: ffff8880b8744a08 FS: 00007f6cbec146c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000080 CR3: 0000000035adc000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052 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_slow_inc_cpuslocked kernel/jump_label.c:168 [inline] static_key_slow_inc_cpuslocked+0x82/0x120 kernel/jump_label.c:151 static_key_slow_inc+0x1a/0x30 kernel/jump_label.c:191 fl_create+0x7f5/0xd40 net/ipv6/ip6_flowlabel.c:458 ipv6_flowlabel_get net/ipv6/ip6_flowlabel.c:639 [inline] ipv6_flowlabel_opt+0xa84/0x2ea0 net/ipv6/ip6_flowlabel.c:742 do_ipv6_setsockopt+0x1052/0x4520 net/ipv6/ipv6_sockglue.c:954 ipv6_setsockopt+0xcb/0x170 net/ipv6/ipv6_sockglue.c:993 tcp_setsockopt+0xa4/0x100 net/ipv4/tcp.c:4030 do_sock_setsockopt+0x222/0x480 net/socket.c:2298 __sys_setsockopt+0x1a0/0x230 net/socket.c:2323 __do_sys_setsockopt net/socket.c:2329 [inline] __se_sys_setsockopt net/socket.c:2326 [inline] __x64_sys_setsockopt+0xbd/0x160 net/socket.c:2326 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: 0033:0x7f6cbdd8cd29 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:00007f6cbec14038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f6cbdfa5fa0 RCX: 00007f6cbdd8cd29 RDX: 0000000000000020 RSI: 0000000000000029 RDI: 0000000000000003 RBP: 00007f6cbde0e2a0 R08: 0000000000000020 R09: 0000000000000000 R10: 0000000020000080 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6cbdfa5fa0 R15: 00007ffdec521118