rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4994/1:b..l rcu: (detected by 0, t=10502 jiffies, g=59717, q=88 ncpus=1) task:udevd state:R running task stack:24840 pid:4994 tgid:4994 ppid:1 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0xa00 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline] RIP: 0010:unwind_next_frame+0x2e7/0x2090 arch/x86/kernel/unwind_orc.c:510 Code: d0 4f 8d 04 40 4f 8d 84 00 7c 8b ba 91 49 81 f8 a0 e6 82 92 0f 87 8f 08 00 00 29 ca 48 8d 3c bd 64 f9 34 91 4c 89 f9 48 89 c6 34 f5 ff ff 48 89 c1 48 85 c9 0f 85 c5 01 00 00 48 b8 00 00 00 RSP: 0018:ffffc9000270f910 EFLAGS: 00000202 RAX: ffffffff91d3312a RBX: 0000000000000001 RCX: ffffffff82787b49 RDX: 0000000000000010 RSI: ffffffff91d3312a RDI: ffffffff914567d8 RBP: ffffc9000270f9c8 R08: ffffffff91d3318a R09: 0000000000000007 R10: 0000000000000200 R11: 000000000001787b R12: ffffc9000270f9d0 R13: ffffc9000270f980 R14: ffffc9000270f9b5 R15: ffffffff82787b49 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x2e5/0x6c0 mm/slub.c:5515 _kmalloc_noprof include/linux/slab.h:969 [inline] slab_free_hook mm/slub.c:2657 [inline] slab_free mm/slub.c:6405 [inline] kmem_cache_free+0x412/0x6b0 mm/slub.c:6532 file_free fs/file_table.c:104 [inline] __fput+0x68d/0xb50 fs/file_table.c:525 fput_close_sync+0x118/0x250 fs/file_table.c:617 __do_sys_close fs/open.c:1511 [inline] __se_sys_close fs/open.c:1496 [inline] __x64_sys_close+0x8b/0x120 fs/open.c:1496 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f17a72a7407 RSP: 002b:00007fffa1d16cf0 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 00007f17a7a3f880 RCX: 00007f17a72a7407 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000000c RBP: 00007f17a7a3f6e8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000016 R13: 00000000ffffffff R14: ffffffffffffffff R15: 00007fffa1d16ff0 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g59717 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=17151 rcu: rcu_preempt kthread starved for 10502 jiffies! g59717 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:28984 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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: CPU: 0 UID: 0 PID: 8139 Comm: syz.0.473 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:__local_bh_enable_ip+0xa6/0x120 kernel/softirq.c:457 Code: 65 01 1d 3d cc 9a 12 65 66 f7 05 34 cc 9a 12 ff ff 74 4d bf 01 00 00 00 e8 a7 2b 0c 00 e8 22 66 49 00 fb 65 8b 05 1a cc 9a 12 <85> c0 74 50 5b 5d e9 3f ad f1 09 65 8b 05 04 0e 9b 12 85 c0 75 a0 RSP: 0018:ffffc90005856c98 EFLAGS: 00000202 RAX: 0000000000000201 RBX: 00000000fffffe00 RCX: 0000000000000004 RDX: 0000000000000000 RSI: ffffffff8e1a59d5 RDI: ffffffff8c400080 RBP: ffffffff8b596401 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffc90005857030 R13: 0000000000000001 R14: 00000000b2f65391 R15: dffffc0000000000 FS: 00007f56693ab6c0(0000) GS:ffff888123df2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3491cff8 CR3: 000000005b788000 CR4: 00000000003526f0 Call Trace: spin_unlock_bh include/linux/spinlock.h:396 [inline] tipc_skb_peek_port net/tipc/msg.h:1235 [inline] tipc_sk_rcv+0x2e1/0x1c80 net/tipc/socket.c:2495 tipc_node_xmit+0x23e/0xfb0 net/tipc/node.c:1701 tipc_node_xmit_skb net/tipc/node.c:1766 [inline] tipc_node_distr_xmit+0x177/0x3c0 net/tipc/node.c:1781 tipc_sk_rcv+0xaab/0x1c80 net/tipc/socket.c:2505 tipc_node_xmit+0x23e/0xfb0 net/tipc/node.c:1701 tipc_sk_push_backlog+0x318/0xa00 net/tipc/socket.c:1313 tipc_sk_filter_connect net/tipc/socket.c:2259 [inline] tipc_sk_filter_rcv+0x95d/0x3250 net/tipc/socket.c:2368 tipc_sk_enqueue net/tipc/socket.c:2449 [inline] tipc_sk_rcv+0xe90/0x1c80 net/tipc/socket.c:2501 tipc_node_xmit+0x23e/0xfb0 net/tipc/node.c:1701 tipc_node_xmit_skb net/tipc/node.c:1766 [inline] tipc_node_distr_xmit+0x177/0x3c0 net/tipc/node.c:1781 tipc_sk_backlog_rcv+0x16f/0x1e0 net/tipc/socket.c:2416 sk_backlog_rcv include/net/sock.h:1190 [inline] __release_sock+0x3a2/0x440 net/core/sock.c:3258 release_sock+0x1e5/0x280 net/core/sock.c:3857 sockopt_release_sock net/core/sock.c:1163 [inline] sk_setsockopt+0x46b/0x5d80 net/core/sock.c:1681 do_sock_setsockopt+0x193/0x1d0 net/socket.c:2364 __sys_setsockopt+0x119/0x190 net/socket.c:2393 __do_sys_setsockopt net/socket.c:2399 [inline] __se_sys_setsockopt net/socket.c:2396 [inline] __x64_sys_setsockopt+0xbd/0x160 net/socket.c:2396 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f566859de59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f56693ab028 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f5668826090 RCX: 00007f566859de59 RDX: 0000000000000021 RSI: 0000000000000001 RDI: 0000000000000003 RBP: 00007f5668633e6f R08: 0000000000000009 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5668826128 R14: 00007f5668826090 R15: 00007fffa2ceaee8