rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4267/1:b..l (detected by 1, t=10503 jiffies, g=6365, q=23 ncpus=2) task:syz-executor633 state:R running task stack:27200 pid:4267 ppid:4263 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696 RIP: 0010:lock_is_held_type+0x13a/0x190 kernel/locking/lockdep.c:5710 Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc90003c778b8 EFLAGS: 00000206 RAX: 2841dec688921500 RBX: ffff888024368000 RCX: 2841dec688921500 RDX: 0000000000000000 RSI: ffffffff8a8c1480 RDI: ffffffff8adefae0 RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff215c249 R10: fffffbfff215c249 R11: 1ffffffff215c248 R12: 0000000000000001 R13: 0000000000000246 R14: ffffffff8cb2a9e0 R15: ffff888024368b08 task_css include/linux/cgroup.h:509 [inline] mem_cgroup_from_task+0x96/0x110 mm/memcontrol.c:985 count_memcg_event_mm+0x196/0x3b0 include/linux/memcontrol.h:1096 handle_mm_fault+0x122/0x3e70 mm/memory.c:5272 do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340 handle_page_fault arch/x86/mm/fault.c:1431 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0010:__put_user_nocheck_8+0x3/0x21 Code: 00 00 48 39 d9 73 34 0f 01 cb 89 01 31 c9 0f 01 ca c3 90 90 90 90 90 90 48 bb f9 ef ff ff ff 7f 00 00 48 39 d9 73 14 0f 01 cb <48> 89 01 31 c9 0f 01 ca c3 90 90 90 90 90 0f 01 ca b9 f2 ff ff ff RSP: 0018:ffffc90003c77d98 EFLAGS: 00050297 RAX: 0000000000000000 RBX: 00007fffffffeff9 RCX: 000055557b0f9da8 RDX: 0000000000000000 RSI: ffffffff8a8c1480 RDI: ffffffff8adefae0 RBP: ffffc90003c77ec0 R08: dffffc0000000000 R09: fffffbfff1c3ee26 R10: fffffbfff1c3ee26 R11: 1ffffffff1c3ee25 R12: ffffc90003c77fd8 R13: dffffc0000000000 R14: 00007fe10d401343 R15: 0000000000000000 clear_rseq_cs kernel/rseq.c:250 [inline] rseq_ip_fixup kernel/rseq.c:284 [inline] __rseq_handle_notify_resume+0x565/0x1220 kernel/rseq.c:322 rseq_handle_notify_resume include/linux/sched.h:2328 [inline] resume_user_mode_work include/linux/resume_user_mode.h:61 [inline] exit_to_user_mode_loop+0xbc/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fe10d401343 RSP: 002b:00007ffd0b62ace8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6 RAX: 0000000000000000 RBX: 00000000000010b1 RCX: 00007fe10d401343 RDX: 00007ffd0b62ad00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffd0b62ad44 R08: 0000000000000043 R09: 003ad847d20ee5c0 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 431bde82d7b634db R14: 000000000001099b R15: 00007ffd0b62ada0 rcu: rcu_preempt kthread starved for 10547 jiffies! g6365 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:27848 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4274 Comm: syz-executor633 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x80 kernel/kcov.c:314 Code: 28 4d 39 ca 77 22 89 ff 89 f6 49 ff c0 4c 89 01 48 c7 44 11 08 03 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 90 <48> 8b 04 24 65 48 8b 15 b4 9b 81 7e 65 8b 0d b5 9b 81 7e 81 e1 00 RSP: 0018:ffffc90003cd7a30 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff8880b8e27280 RCX: 0000000000000838 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff1c3ee26 R10: fffffbfff1c3ee26 R11: 1ffffffff1c3ee25 R12: dffffc0000000000 R13: 0000000010007f81 R14: 0000000000000000 R15: 0000000000000020 FS: 00007fe10d3946c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000058 CR3: 000000002d949000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: clockevents_program_event+0x1c8/0x310 kernel/time/clockevents.c:336 hrtimer_start_range_ns+0xb9a/0xfc0 kernel/time/hrtimer.c:1354 posixtimer_rearm+0x131/0x340 kernel/time/posix-timers.c:329 dequeue_signal+0x1b6/0x4b0 kernel/signal.c:704 get_signal+0x547/0x1350 kernel/signal.c:2751 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fe10d3d4687 Code: 14 25 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 18 00 00 90 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 b0 ff ff ff f7 d8 64 89 RSP: 002b:00007fe10d394178 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007fe10d45e3c8 RCX: 00007fe10d3d4689 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fe10d45e3c8 RBP: 00007fe10d45e3c0 R08: 00007fe10d3946c0 R09: 00007fe10d3946c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe10d45e3cc R13: 0000000000000000 R14: 00007ffd0b62ab60 R15: 00007ffd0b62ac48