rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-....: (36 ticks this GP) idle=541/1/0x4000000000000000 softirq=27827/27829 fqs=5247 (detected by 1, t=10502 jiffies, g=41369, q=4701) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 10149 Comm: syz.9.1414 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:trace_hardirqs_on+0x1/0x80 kernel/trace/trace_preemptirq.c:41 Code: e9 94 fe ff ff e8 ef e1 f9 ff 0f 0b e9 39 ff ff ff e8 e3 e1 f9 ff e8 56 91 82 ff e9 79 fe ff ff 66 0f 1f 84 00 00 00 00 00 53 ca e1 f9 ff 65 8b 1d 9b 49 85 7e 31 ff 89 de e8 1a e5 f9 ff 85 RSP: 0018:ffffc90000007588 EFLAGS: 00000002 RAX: 0000000000000102 RBX: 0000000000000000 RCX: 3d1e882196384700 RDX: 1ffffffff1dda200 RSI: 0000000000000000 RDI: ffffc90000007598 RBP: 0000000000000000 R08: ffffffff8eed1008 R09: ffffffff8eed1018 R10: ffffffff8eed1010 R11: ffffffff8eed1003 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f58c54b26c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f82cecafdac CR3: 000000001f6f7000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: 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:ffffc90000007640 EFLAGS: 00000206 RAX: 3d1e882196384700 RBX: 1ffff92000000ecc RCX: 3d1e882196384700 RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a480 RBP: ffffc90000007720 R08: dffffc0000000000 R09: fffffbfff1ff7832 R10: fffffbfff1ff7832 R11: 1ffffffff1ff7831 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] __ip_queue_xmit+0x1244/0x1c00 net/ipv4/ip_output.c:533 __tcp_transmit_skb+0x1ced/0x31c0 net/ipv4/tcp_output.c:1404 tcp_transmit_skb net/ipv4/tcp_output.c:1422 [inline] __tcp_retransmit_skb+0x92c/0x1290 net/ipv4/tcp_output.c:3267 tcp_retransmit_skb+0x2e/0x350 net/ipv4/tcp_output.c:3290 tcp_retransmit_timer+0x144b/0x2540 net/ipv4/tcp_timer.c:570 tcp_write_timer_handler+0x205/0x9a0 net/ipv4/tcp_timer.c:655 tcp_write_timer+0x126/0x280 net/ipv4/tcp_timer.c:675 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:finish_lock_switch+0x134/0x280 kernel/sched/core.c:4804 Code: be ff ff ff ff e8 4c 7d 55 08 85 c0 74 4a 4d 85 ff 75 66 0f 1f 44 00 00 48 89 df e8 a6 e7 5e 08 e8 c1 75 2a 00 fb 48 83 c4 08 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 48 89 df e8 d9 0f fe ff 43 80 3c RSP: 0018:ffffc9000300f8c8 EFLAGS: 00000282 RAX: 3d1e882196384700 RBX: ffff8880b903a340 RCX: 3d1e882196384700 RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a480 RBP: 1ffff11017207613 R08: dffffc0000000000 R09: ffffed1017207662 R10: ffffed1017207662 R11: 1ffff11017207661 R12: 1ffff110172075c1 R13: dffffc0000000000 R14: ffff8880b903ae08 R15: 0000000000000000 finish_task_switch+0x12f/0x640 kernel/sched/core.c:4921 context_switch kernel/sched/core.c:5052 [inline] __schedule+0x11c3/0x4390 kernel/sched/core.c:6395 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6799 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:do_futex+0x10d/0x1240 kernel/futex/core.c:3979 Code: 00 00 75 37 e8 64 2e 0c 00 4c 89 f7 48 c7 c6 30 84 13 8c e8 b5 32 0c 00 41 83 fd 0d 0f 87 da 08 00 00 42 ff 24 f5 c0 00 0d 8a 3e 2e 0c 00 c7 45 10 ff ff ff ff e9 e7 0b 00 00 83 cb 02 4c 89 RSP: 0018:ffffc9000300fca0 EFLAGS: 00000297 RAX: 000000000000000d RBX: 0000000000000000 RCX: 0000000000000005 RDX: ffffffff816b9ccb RSI: ffffffff8c138430 RDI: 0000000000000000 RBP: ffffc9000300fe08 R08: ffff88802b4f8000 R09: 000000000000000d R10: 000000000000000d R11: 0000000000000002 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 __do_sys_futex kernel/futex/core.c:4059 [inline] __se_sys_futex+0x3a3/0x430 kernel/futex/core.c:4040 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: 0033:0x7f58c724aba9 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:00007f58c54b20e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f58c7491fa8 RCX: 00007f58c724aba9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f58c7491fa8 RBP: 00007f58c7491fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f58c7492038 R14: 00007ffe7976ae40 R15: 00007ffe7976af28