rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P17676/1:b..l rcu: (detected by 1, t=10502 jiffies, g=70281, q=145 ncpus=2) task:syz.5.4046 state:R running task stack:25952 pid:17676 tgid:17675 ppid:12118 task_flags:0x400140 flags:0x00024002 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7087 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:lock_acquire.part.0+0x155/0x380 kernel/locking/lockdep.c:5816 Code: b8 ff ff ff ff 65 0f c1 05 10 d9 6b 7e 83 f8 01 0f 85 d0 01 00 00 9c 58 f6 c4 02 0f 85 e5 01 00 00 48 85 ed 0f 85 b6 01 00 00 <48> b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00 00 00 00 48 c7 RSP: 0018:ffffc9000fa97500 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 1ffff92001f52ea1 RCX: 00000000021efa7b RDX: 0000000000000001 RSI: ffffffff8b6cf100 RDI: ffffffff8bd35a60 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff2dd8598 R10: ffffffff96ec2cc7 R11: 0000000000000003 R12: 0000000000000000 R13: ffffffff8e1bccc0 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] percpu_ref_put_many.constprop.0+0x2f/0x150 include/linux/percpu-refcount.h:330 percpu_ref_put include/linux/percpu-refcount.h:351 [inline] css_put include/linux/cgroup_refcnt.h:79 [inline] css_put include/linux/cgroup_refcnt.h:76 [inline] __memcg_slab_post_alloc_hook+0x5b4/0x9b0 mm/memcontrol.c:2982 memcg_slab_post_alloc_hook mm/slub.c:2152 [inline] slab_post_alloc_hook mm/slub.c:4125 [inline] slab_alloc_node mm/slub.c:4164 [inline] kmem_cache_alloc_lru_noprof+0x363/0x3d0 mm/slub.c:4183 sock_alloc_inode+0x25/0x1c0 net/socket.c:309 alloc_inode+0x5d/0x230 fs/inode.c:336 sock_alloc+0x40/0x280 net/socket.c:622 __sock_create+0xc1/0x8d0 net/socket.c:1512 udp_sock_create6+0xc8/0x6a0 net/ipv6/ip6_udp_tunnel.c:24 udp_sock_create include/net/udp_tunnel.h:62 [inline] rxrpc_open_socket+0x20c/0x6c0 net/rxrpc/local_object.c:187 rxrpc_lookup_local+0xa02/0x1220 net/rxrpc/local_object.c:293 rxrpc_sendmsg+0x375/0x5f0 net/rxrpc/af_rxrpc.c:608 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:733 [inline] sock_write_iter+0x4fe/0x5b0 net/socket.c:1137 io_write+0x53b/0x1470 io_uring/rw.c:1110 io_issue_sqe+0x172/0x1300 io_uring/io_uring.c:1737 io_queue_sqe io_uring/io_uring.c:1947 [inline] io_submit_sqe io_uring/io_uring.c:2204 [inline] io_submit_sqes+0x96a/0x2670 io_uring/io_uring.c:2321 __do_sys_io_uring_enter+0xd60/0x1670 io_uring/io_uring.c:3372 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: 0033:0x7fd5bd18d169 RSP: 002b:00007fd5bdf8e038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 00007fd5bd3a5fa0 RCX: 00007fd5bd18d169 RDX: 0000000000000000 RSI: 0000000000003516 RDI: 0000000000000004 RBP: 00007fd5bd20e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fd5bd3a5fa0 R15: 00007ffd625db138 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g70281 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=58438 rcu: rcu_preempt kthread starved for 10502 jiffies! g70281 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26960 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 17680 Comm: syz.7.4044 Not tainted 6.14.0-rc4-syzkaller-00242-g7a5668899f54 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x12/0xc0 kernel/rcu/tree.c:716 Code: 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 53 65 ff 05 0b 53 64 7e e8 9e c6 b7 09 <48> c7 c3 28 7c 03 00 83 f8 07 89 c5 0f 87 82 00 00 00 48 8d 3c ed RSP: 0018:ffffc90000007cc8 EFLAGS: 00000082 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8195c31c RDX: fffffbfff20c4b03 RSI: ffffffff8bd359e0 RDI: ffffffff8bd35a20 RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff20c4b02 R10: ffffffff90625817 R11: 0000000000000002 R12: 0000000000000000 R13: 000000000003d94c R14: 0000000000000001 R15: 0000000000000000 FS: 00007f58080776c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2da03ff8 CR3: 00000000379ee000 CR4: 00000000003526f0 DR0: 0000000000000007 DR1: 0000000000000002 DR2: 0000000000000008 DR3: 1000000100000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_lock_acquire+0x14e/0x1f0 include/trace/events/lock.h:24 lock_acquire+0x2f/0xb0 kernel/locking/lockdep.c:5822 __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:1801 [inline] __hrtimer_run_queues+0x20a/0xae0 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1927 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 86 dc 3c f6 48 89 df e8 de 5b 3d f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 55 31 2e f6 65 8b 05 a6 13 aa 74 85 c0 74 16 5b RSP: 0018:ffffc9000ebc7ca8 EFLAGS: 00000246 RAX: 0000000000000006 RBX: ffff8880b862c680 RCX: 1ffffffff2dd8673 RDX: 0000000000000000 RSI: ffffffff8b6cee00 RDI: ffffffff8bd35a60 RBP: 0000000000000282 R08: 0000000000000001 R09: fffffbfff2dd8598 R10: ffffffff96ec2cc7 R11: 0000000000000001 R12: fc672fdd2fa66b31 R13: 0000000000000000 R14: 000000ca72787565 R15: dffffc0000000000 clock_was_set+0x591/0x850 kernel/time/hrtimer.c:984 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: 0033:0x7f580718d169 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:00007f5808077038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f58073a6160 RCX: 00007f580718d169 RDX: 0000000000000000 RSI: 0000400000003c80 RDI: 0000000000000000 RBP: 00007f580720e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f58073a6160 R15: 00007ffc0916b5b8