rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5473/1:b..l (detected by 1, t=10505 jiffies, g=10417, q=1398) task:syz.4.321 state:R running task stack:26528 pid: 5473 ppid: 4187 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6552 preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6577 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0xf6/0x100 kernel/locking/spinlock.c:194 queue_stack_map_push_elem+0x37c/0x5e0 kernel/bpf/queue_stack_maps.c:235 bpf_prog_216c997a1f42e404+0x37/0x51c bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] bpf_test_run+0x292/0x7d0 net/bpf/test_run.c:119 bpf_prog_test_run_skb+0x9cc/0x1180 net/bpf/test_run.c:669 bpf_prog_test_run+0x31e/0x390 kernel/bpf/syscall.c:3368 __sys_bpf+0x535/0x670 kernel/bpf/syscall.c:4669 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline] __se_sys_bpf kernel/bpf/syscall.c:4753 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fa565ebfbe9 RSP: 002b:00007fa564106038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fa5660e7090 RCX: 00007fa565ebfbe9 RDX: 0000000000000050 RSI: 0000200000000000 RDI: 000000000000000a RBP: 00007fa565f42e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa5660e7128 R14: 00007fa5660e7090 R15: 00007ffec9153318 rcu: rcu_preempt kthread timer wakeup didn't happen for 10500 jiffies! g10417 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=6365 rcu: rcu_preempt kthread starved for 10501 jiffies! g10417 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:27848 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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: 5479 Comm: syz.1.324 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:172 [inline] RIP: 0010:write_comp_data kernel/kcov.c:227 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp8+0xc/0x80 kernel/kcov.c:300 Code: 44 02 08 05 00 00 00 4a 89 7c 02 10 4a 89 74 02 18 4a 89 44 02 20 48 ff c1 48 89 0a c3 90 48 8b 04 24 65 48 8b 0d b4 a7 8a 7e <65> 8b 15 b5 a7 8a 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 RSP: 0018:ffffc90000007668 EFLAGS: 00000046 RAX: ffffffff81960880 RBX: 0000000000092000 RCX: ffff8880284ebb80 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: dffffc0000000000 R09: ffffc90000007800 R10: fffff52000000f07 R11: 1ffff92000000f00 R12: ffff88805b503712 R13: ffffc900000079c0 R14: ffff88805b5035b8 R15: ffffc90000007866 FS: 00007fcf173b56c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000000b000 CR3: 000000007c97b000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __perf_event_header__init_id+0x290/0x500 kernel/events/core.c:7095 perf_prepare_sample+0x158/0x1cb0 kernel/events/core.c:7610 __perf_event_output kernel/events/core.c:7788 [inline] perf_event_output_forward+0x146/0x280 kernel/events/core.c:7808 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9501 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10033 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10007 perf_trace_preemptirq_template+0x2be/0x380 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:ffs arch/x86/include/asm/bitops.h:297 [inline] RIP: 0010:handle_softirqs+0x1a9/0x820 kernel/softirq.c:564 Code: 24 78 44 89 64 24 28 0f b7 db 48 c7 c7 c0 fd 09 8a e8 cb c8 5f 08 65 66 c7 05 e1 22 bb 7e 00 00 e8 4c 6c 35 00 fb 89 5c 24 34 ff ff ff ff 0f bc 44 24 34 41 89 c5 41 ff c5 0f 85 c1 00 00 00 RSP: 0018:ffffc90000007e20 EFLAGS: 00000282 RAX: bc1c6ddbdd50da00 RBX: 0000000000000200 RCX: bc1c6ddbdd50da00 RDX: dffffc0000000000 RSI: ffffffff8a0b15c0 RDI: ffffffff8a599340 RBP: ffffc90000007f30 R08: dffffc0000000000 R09: fffffbfff1ff6e1f R10: fffffbfff1ff6e1f R11: 1ffffffff1ff6e1e R12: 000000000000000a R13: 0000000000000000 R14: ffff8880284ebb80 R15: dffffc0000000000 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__rcu_read_unlock+0x73/0xd0 kernel/rcu/tree_plugin.h:422 Code: 84 c0 75 5f 41 83 3e 00 75 20 43 0f b6 04 3c 84 c0 75 3a 8b 03 3d 00 00 00 40 73 0a 5b 41 5c 41 5d 41 5e 41 5f c3 0f 0b eb f2 58 00 00 00 eb d9 89 d9 80 e1 07 80 c1 03 38 c1 7c ac 49 89 fe RSP: 0018:ffffc9000322ee90 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffff8880284ebfbc RCX: 0000000000080000 RDX: ffffc90003d11000 RSI: 00000000000054f7 RDI: ffff8880284ebb80 RBP: ffffc9000322ef70 R08: dffffc0000000000 R09: fffffbfff1ff6e1f R10: fffffbfff1ff6e1f R11: 1ffffffff1ff6e1e R12: 1ffff1100509d7f7 R13: 1ffff92000645dd8 R14: ffff8880284ebfc0 R15: dffffc0000000000 rcu_read_unlock include/linux/rcupdate.h:771 [inline] count_memcg_event_mm+0x30c/0x360 include/linux/memcontrol.h:1082 handle_mm_fault+0x12d/0x43c0 mm/memory.c:4863 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1357 handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1501 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0010:copy_user_enhanced_fast_string+0xe/0x40 arch/x86/lib/copy_user_64.S:206 Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 90 90 90 90 90 90 90 0f 01 cb 83 fa 40 0f 82 70 ff ff ff 89 d1 a4 31 c0 0f 01 ca c3 90 90 90 90 90 90 90 90 90 90 89 d1 83 f8 RSP: 0018:ffffc9000322f2d8 EFLAGS: 00050202 RAX: ffffffff83d87001 RBX: 0000000000000d50 RCX: 0000000000000a74 RDX: 0000000000000d50 RSI: 000020000000b000 RDI: ffff8880230163d4 RBP: ffffc9000322f438 R08: dffffc0000000000 R09: ffffed1004602dc9 R10: 0000000000000000 R11: 00000000000001a8 R12: ffff8880230160f8 R13: dffffc00000000ff R14: 000020000000ad24 R15: 000000000000ace4 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:52 [inline] copyin lib/iov_iter.c:168 [inline] _copy_from_iter+0x314/0x1150 lib/iov_iter.c:776 copy_from_iter include/linux/uio.h:164 [inline] copy_from_iter_full include/linux/uio.h:170 [inline] tipc_msg_build+0x7f4/0xde0 net/tipc/msg.c:439 tipc_send_group_bcast+0x764/0xa70 net/tipc/socket.c:1128 __tipc_sendmsg+0x2dd/0x2980 net/tipc/socket.c:1436 tipc_sendmsg+0x51/0x70 net/tipc/socket.c:1403 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] sock_write_iter+0x29c/0x380 net/socket.c:1079 call_write_iter include/linux/fs.h:2172 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x712/0xd00 fs/read_write.c:594 ksys_write+0x14d/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fcf1914dbe9 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:00007fcf173b5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fcf19374fa0 RCX: 00007fcf1914dbe9 RDX: 000000000000fdef RSI: 0000200000000040 RDI: 0000000000000007 RBP: 00007fcf191d0e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcf19375038 R14: 00007fcf19374fa0 R15: 00007fffaa4d4ca8