rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5808/4:b..l P5165/1:b..l P3181/3:b..l rcu: (detected by 0, t=10502 jiffies, g=33561, q=372 ncpus=2) task:kworker/u8:10 state:R running task stack:22216 pid:3181 tgid:3181 ppid:2 task_flags:0x4208160 flags:0x00080000 Workqueue: tipc_rcv tipc_conn_recv_work Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 class_preempt_destructor include/linux/preempt.h:470 [inline] try_to_wake_up+0x82b/0x12b0 kernel/sched/core.c:4300 autoremove_wake_function+0x17/0x100 kernel/sched/wait.c:403 __wake_up_common kernel/sched/wait.c:108 [inline] __wake_up_common_lock+0x136/0x1e0 kernel/sched/wait.c:125 release_sock+0x183/0x210 net/core/sock.c:3743 tipc_recvmsg+0xb32/0x13c0 net/tipc/socket.c:1994 sock_recvmsg_nosec net/socket.c:1078 [inline] sock_recvmsg+0x229/0x270 net/socket.c:1100 tipc_conn_rcv_from_sock net/tipc/topsrv.c:401 [inline] tipc_conn_recv_work+0x27b/0x480 net/tipc/topsrv.c:424 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4b9/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:udevd state:R running task stack:24840 pid:5165 tgid:5165 ppid:1 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x97/0xa0 kernel/kcov.c:316 Code: 8d 51 28 4d 39 ca 77 22 89 ff 89 f6 49 ff c0 4c 89 02 48 c7 44 0a 08 05 00 00 00 48 89 7c 0a 10 48 89 74 0a 18 48 89 44 0a 20 14 fd 0a 09 cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90003b57778 EFLAGS: 00000293 RAX: ffffffff82326547 RBX: ffffffff82326517 RCX: ffff8880360b9e00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed1027fc683c R12: 1ffff9200076af57 R13: ffff88803bf3f810 R14: ffff88803bf3f130 R15: dffffc0000000000 rcu_read_lock include/linux/rcupdate.h:868 [inline] dput+0x67/0x2b0 fs/dcache.c:904 step_into+0x319/0xf20 fs/namei.c:2004 walk_component fs/namei.c:2157 [inline] link_path_walk+0x77b/0xea0 fs/namei.c:2519 path_lookupat+0x97/0x430 fs/namei.c:2675 filename_lookup+0x212/0x570 fs/namei.c:2705 vfs_statx+0xf8/0x550 fs/stat.c:353 vfs_fstatat+0x118/0x170 fs/stat.c:375 __do_sys_newfstatat fs/stat.c:542 [inline] __se_sys_newfstatat fs/stat.c:536 [inline] __x64_sys_newfstatat+0x116/0x190 fs/stat.c:536 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f650e23fb0a RSP: 002b:00007ffef3ddfbf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007ffef3de0090 RCX: 00007f650e23fb0a RDX: 00007ffef3ddfc00 RSI: 00007ffef3de0090 RDI: 00000000ffffff9c RBP: 000055593258b910 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffef3ddfc90 R13: 00000000000000fe R14: 00005558f4a63be0 R15: 00007ffef3de0790 task:syz-executor state:R running task stack:18736 pid:5808 tgid:5808 ppid:5796 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x40/0x80 kernel/kcov.c:217 Code: 07 10 81 e6 00 00 ff 00 ba 00 01 00 00 23 91 4c 0b 00 00 89 d7 09 f7 74 11 85 f6 75 39 85 d2 74 35 83 b9 14 16 00 00 00 74 2c <8b> 91 f0 15 00 00 83 fa 02 75 21 48 8b 91 f8 15 00 00 48 8b 32 48 RSP: 0018:ffffc90004d3f3a8 EFLAGS: 00000246 RAX: ffffffff8226ba82 RBX: 80000000375c5007 RCX: ffff888039ca9e00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff940001bae29 R12: dffffc0000000000 R13: ffff8880287758e0 R14: ffff88803bb273d0 R15: ffff88803b8cae00 __page_table_check_ptes_set+0x22/0x2f0 mm/page_table_check.c:198 page_table_check_ptes_set include/linux/page_table_check.h:76 [inline] set_ptes include/linux/pgtable.h:292 [inline] __copy_present_ptes mm/memory.c:1100 [inline] copy_present_ptes mm/memory.c:1179 [inline] copy_pte_range mm/memory.c:1302 [inline] copy_pmd_range+0x4790/0x7950 mm/memory.c:1389 copy_pud_range mm/memory.c:1426 [inline] copy_p4d_range mm/memory.c:1450 [inline] copy_page_range+0xaff/0x1170 mm/memory.c:1538 dup_mmap+0xf5b/0x1ae0 mm/mmap.c:1834 dup_mm kernel/fork.c:1489 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1541 copy_process+0x1704/0x3ae0 kernel/fork.c:2181 kernel_clone+0x224/0x7c0 kernel/fork.c:2609 __do_sys_clone kernel/fork.c:2750 [inline] __se_sys_clone kernel/fork.c:2734 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2734 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f57fa3e5613 RSP: 002b:00007ffc4d92f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f57fa3e5613 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055557de8c7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 000055557de9f590 R14: 00000000000b343a R15: 00007ffc4d92f1d0 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g33561 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=25737 rcu: rcu_preempt kthread starved for 10502 jiffies! g33561 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26384 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4b9/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 12097 Comm: syz.1.1967 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:mark_usage kernel/locking/lockdep.c:4627 [inline] RIP: 0010:__lock_acquire+0x5f2/0xd20 kernel/locking/lockdep.c:5191 Code: 41 38 c5 76 1a e8 ee 09 e1 02 48 8b 3c 24 85 c0 74 0d 83 3d b3 ef 5b 0d 00 0f 84 1a 05 00 00 83 7c 24 0c 00 0f 84 a9 00 00 00 <41> 8b 46 20 66 85 c0 0f 88 8d 00 00 00 65 8b 0d 26 06 2a 10 a9 00 RSP: 0018:ffffc900063af030 EFLAGS: 00000002 RAX: 00000000ffffff05 RBX: 0000000000000001 RCX: 0000000000000001 RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff888032353c00 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81843291 R10: dffffc0000000000 R11: ffffed1029a9b861 R12: 00000000ffffff05 R13: 0000000000000001 R14: ffff888032354788 R15: ffff8880323547a8 FS: 00007f739759d6c0(0000) GS:ffff888126ccb000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8eed0d7ff8 CR3: 000000004a046000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __local_bh_disable_ip+0xc5/0x540 kernel/softirq.c:163 local_bh_disable include/linux/bottom_half.h:20 [inline] rt_spin_trylock_bh+0x33/0x2f0 kernel/locking/spinlock_rt.c:126 tipc_sk_rcv+0x45f/0x2d20 net/tipc/socket.c:2494 tipc_node_xmit+0x1e4/0xe40 net/tipc/node.c:1701 __tipc_sendstream+0xb09/0x1290 net/tipc/socket.c:1622 tipc_sendstream+0x55/0x70 net/tipc/socket.c:1546 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:742 sock_write_iter+0x27f/0x370 net/socket.c:1195 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5d5/0xb40 fs/read_write.c:686 ksys_write+0x14b/0x260 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f739935eec9 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:00007f739759d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f73995b6090 RCX: 00007f739935eec9 RDX: 000000002000011a RSI: 0000200000000080 RDI: 0000000000000009 RBP: 00007f73993e1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f73995b6128 R14: 00007f73995b6090 R15: 00007ffc56752598