rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (2 ticks this GP) idle=c7f/1/0x4000000000000002 softirq=69098/69098 fqs=0 (detected by 1, t=10502 jiffies, g=106625, q=710) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 20602 Comm: syz.5.3962 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:check_preemption_disabled+0x6/0x110 lib/smp_processor_id.c:13 Code: d0 12 8a e8 2c 01 00 00 65 ff 0d 11 56 5a 76 5b c3 00 00 cc 48 c7 c7 20 a4 59 8a 48 c7 c6 60 a4 59 8a eb 00 55 41 57 41 56 53 <48> 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65 8b 05 c9 RSP: 0018:ffffc900000076b0 EFLAGS: 00000046 RAX: 53f015592e331100 RBX: ffffc900000076f8 RCX: 53f015592e331100 RDX: 1ffffffff1dda200 RSI: ffffffff8a0a0080 RDI: ffffffff8a59a480 RBP: 0000000000000000 R08: ffffffff8eed1008 R09: ffffffff8eed1018 R10: ffffffff8eed1010 R11: ffffffff8eed1003 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f1d67cee6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1d67cacd58 CR3: 000000007d4ab000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: irq_exit_rcu+0x11/0x20 kernel/softirq.c:673 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0x4f/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674 Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ad 13 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b RSP: 0018:ffffc900000077a0 EFLAGS: 00000206 RAX: 53f015592e331100 RBX: 1ffff92000000ef8 RCX: 53f015592e331100 RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a480 RBP: ffffc90000007880 R08: dffffc0000000000 R09: fffffbfff1ff7839 R10: fffffbfff1ff7839 R11: 1ffffffff1ff7838 R12: ffffffff8c120b00 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:771 [inline] ndisc_send_skb+0xdc4/0x14a0 net/ipv6/ndisc.c:521 addrconf_rs_timer+0x2b8/0x600 net/ipv6/addrconf.c:3956 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x525/0x7c0 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x328/0x820 kernel/softirq.c:576 __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:put_cpu_partial+0x15e/0x190 mm/slub.c:2591 Code: 00 00 48 3b 44 24 08 75 4d 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 0f 29 ed 07 41 f7 c5 00 02 00 00 74 c3 fb 4d 85 ff <75> c2 eb cb 48 c7 c7 70 fc 1e 8c 4c 89 e6 e8 7f f0 3e 02 e9 e5 fe RSP: 0018:ffffc9000327fa48 EFLAGS: 00000246 RAX: 53f015592e331100 RBX: ffff888016841dc0 RCX: 53f015592e331100 RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a480 RBP: 0000000000000001 R08: dffffc0000000000 R09: ffffed1017207662 R10: ffffed1017207662 R11: 1ffff11017207661 R12: 0000000000000000 R13: 0000000000000286 R14: ffff8880b903df60 R15: 0000000000000000 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x100/0x290 mm/slub.c:3238 sock_alloc_inode+0x17/0xb0 net/socket.c:303 alloc_inode fs/inode.c:261 [inline] new_inode_pseudo+0x5f/0x210 fs/inode.c:1001 sock_alloc net/socket.c:626 [inline] __sock_create+0x129/0x900 net/socket.c:1450 sock_create net/socket.c:1542 [inline] __sys_socketpair+0x1bd/0x540 net/socket.c:1642 __do_sys_socketpair net/socket.c:1695 [inline] __se_sys_socketpair net/socket.c:1692 [inline] __x64_sys_socketpair+0x97/0xb0 net/socket.c:1692 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: 0033:0x7f1d69a86ba9 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:00007f1d67cee038 EFLAGS: 00000246 ORIG_RAX: 0000000000000035 RAX: ffffffffffffffda RBX: 00007f1d69ccdfa0 RCX: 00007f1d69a86ba9 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000001 RBP: 00007f1d69b09e19 R08: 0000000000000000 R09: 0000000000000000 R10: 00002000000029c0 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1d69cce038 R14: 00007f1d69ccdfa0 R15: 00007ffef8e0d978 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g106625 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=44830 rcu: rcu_preempt kthread starved for 10502 jiffies! g106625 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:27008 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 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: 20602 Comm: syz.5.3962 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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+0x23/0x80 kernel/kcov.c:300 Code: ff c1 48 89 0a c3 90 48 8b 04 24 65 48 8b 0d b4 a0 8a 7e 65 8b 15 b5 a0 8a 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 57 <83> b9 34 16 00 00 00 74 4e 8b 91 10 16 00 00 83 fa 03 75 43 48 8b RSP: 0018:ffffc90000007038 EFLAGS: 00000046 RAX: ffffffff81964fbd RBX: ffffc900000071e0 RCX: ffff88807ebc3b80 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000007130 R08: dffffc0000000000 R09: ffffc90000007180 R10: fffff52000000e37 R11: 1ffff92000000e30 R12: dffffc0000000000 R13: ffffc900000071e6 R14: 0000000000000000 R15: ffffc90000007340 FS: 00007f1d67cee6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1d67cacd58 CR3: 000000007d4ab000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: perf_prepare_sample+0x8dd/0x1cb0 kernel/events/core.c:7680 __perf_event_output kernel/events/core.c:7802 [inline] perf_event_output_forward+0x146/0x280 kernel/events/core.c:7822 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10047 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021 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:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674 Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ad 13 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b RSP: 0018:ffffc900000077a0 EFLAGS: 00000206 RAX: 53f015592e331100 RBX: 1ffff92000000ef8 RCX: 53f015592e331100 RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a480 RBP: ffffc90000007880 R08: dffffc0000000000 R09: fffffbfff1ff7839 R10: fffffbfff1ff7839 R11: 1ffffffff1ff7838 R12: ffffffff8c120b00 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:771 [inline] ndisc_send_skb+0xdc4/0x14a0 net/ipv6/ndisc.c:521 addrconf_rs_timer+0x2b8/0x600 net/ipv6/addrconf.c:3956 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x525/0x7c0 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x328/0x820 kernel/softirq.c:576 __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:put_cpu_partial+0x15e/0x190 mm/slub.c:2591 Code: 00 00 48 3b 44 24 08 75 4d 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 0f 29 ed 07 41 f7 c5 00 02 00 00 74 c3 fb 4d 85 ff <75> c2 eb cb 48 c7 c7 70 fc 1e 8c 4c 89 e6 e8 7f f0 3e 02 e9 e5 fe RSP: 0018:ffffc9000327fa48 EFLAGS: 00000246 RAX: 53f015592e331100 RBX: ffff888016841dc0 RCX: 53f015592e331100 RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a480 RBP: 0000000000000001 R08: dffffc0000000000 R09: ffffed1017207662 R10: ffffed1017207662 R11: 1ffff11017207661 R12: 0000000000000000 R13: 0000000000000286 R14: ffff8880b903df60 R15: 0000000000000000 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x100/0x290 mm/slub.c:3238 sock_alloc_inode+0x17/0xb0 net/socket.c:303 alloc_inode fs/inode.c:261 [inline] new_inode_pseudo+0x5f/0x210 fs/inode.c:1001 sock_alloc net/socket.c:626 [inline] __sock_create+0x129/0x900 net/socket.c:1450 sock_create net/socket.c:1542 [inline] __sys_socketpair+0x1bd/0x540 net/socket.c:1642 __do_sys_socketpair net/socket.c:1695 [inline] __se_sys_socketpair net/socket.c:1692 [inline] __x64_sys_socketpair+0x97/0xb0 net/socket.c:1692 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: 0033:0x7f1d69a86ba9 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:00007f1d67cee038 EFLAGS: 00000246 ORIG_RAX: 0000000000000035 RAX: ffffffffffffffda RBX: 00007f1d69ccdfa0 RCX: 00007f1d69a86ba9 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000001 RBP: 00007f1d69b09e19 R08: 0000000000000000 R09: 0000000000000000 R10: 00002000000029c0 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1d69cce038 R14: 00007f1d69ccdfa0 R15: 00007ffef8e0d978