rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-....: (1 GPs behind) idle=4fb/1/0x4000000000000002 softirq=45304/45305 fqs=5242 (detected by 1, t=10502 jiffies, g=59849, q=1609) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 16429 Comm: syz.0.4138 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:check_kcov_mode kernel/kcov.c:172 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x2a/0x60 kernel/kcov.c:206 Code: 48 8b 04 24 65 48 8b 0d 14 7d 89 7e 65 8b 15 15 7d 89 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00 00 <74> 2c 8b 91 10 16 00 00 83 fa 02 75 21 48 8b 91 18 16 00 00 48 8b RSP: 0018:ffffc90000007230 EFLAGS: 00000046 RAX: ffffffff81977b5a RBX: 0000000000000000 RCX: ffff88801e0a8000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff8d89e06f R09: 1ffffffff1b13c0d R10: dffffc0000000000 R11: fffffbfff1b13c0e R12: 0000000000001dca R13: ffffc90000007580 R14: ffffc900000075e0 R15: 0000000000001dca FS: 00007ff5dbaa46c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000035e00000000 CR3: 000000006790f000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __perf_event_header__init_id+0x3ea/0x4f0 kernel/events/core.c:7118 perf_prepare_sample+0x158/0x1cb0 kernel/events/core.c:7624 __perf_event_output kernel/events/core.c:7802 [inline] perf_event_output_forward+0x185/0x2e0 kernel/events/core.c:7822 __perf_event_overflow+0x35f/0x550 kernel/events/core.c:9515 perf_tp_event+0x324/0xbe0 kernel/events/core.c:10047 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021 perf_trace_preemptirq_template+0x2aa/0x360 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+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674 Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 c2 22 9d 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc900000079c0 EFLAGS: 00000206 RAX: b153a2b522221400 RBX: 1ffff92000000f3c RCX: b153a2b522221400 RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a79c980 RBP: ffffc90000007aa0 R08: ffffffff901cb1bf R09: 1ffffffff2039637 R10: dffffc0000000000 R11: fffffbfff2039638 R12: ffffffff8c323400 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] hsr_announce+0x29a/0x310 net/hsr/hsr_device.c:410 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648 expire_timers kernel/time/timer.c:1699 [inline] __run_timers+0x56c/0x810 kernel/time/timer.c:1970 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983 handle_softirqs+0x336/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 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+0x12f/0x290 kernel/sched/core.c:4804 Code: 83 c7 18 be ff ff ff ff e8 fe 8c 65 08 85 c0 74 46 4d 85 ff 75 62 0f 1f 44 00 00 48 89 df e8 28 f7 6e 08 e8 83 ce 2a 00 fb 5b <41> 5c 41 5d 41 5e 41 5f 5d c3 48 89 df e8 2f 0e fe ff 43 80 3c 2c RSP: 0018:ffffc900032df878 EFLAGS: 00000282 RAX: b153a2b522221400 RBX: ffff88807f1bbb80 RCX: b153a2b522221400 RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a79c980 RBP: 1ffff11017207613 R08: ffff8880b903b30b R09: 1ffff11017207661 R10: dffffc0000000000 R11: ffffed1017207662 R12: 1ffff110172075c1 R13: dffffc0000000000 R14: ffff8880b903ae08 R15: 0000000000000000 finish_task_switch+0x12f/0x650 kernel/sched/core.c:4921 context_switch kernel/sched/core.c:5052 [inline] __schedule+0x11cb/0x4350 kernel/sched/core.c:6395 preempt_schedule_irq+0xbb/0x160 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:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:64 Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 RSP: 0018:ffffc900032dfc50 EFLAGS: 00010246 RAX: ffff88805d4d6500 RBX: 0000000000000000 RCX: 0000000000000078 RDX: 0000000000000138 RSI: 0000000000000000 RDI: ffff88805d4d66a0 RBP: 0000000000000001 R08: 000000000000000b R09: ffff88805d4d65e0 R10: 0000000000000001 R11: 00000000babb88dc R12: 0000000000000001 R13: ffff888016de9640 R14: 0000000000000cc0 R15: ffffc900032dfcc0 slab_post_alloc_hook+0x68/0x380 mm/slab.h:521 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x15d/0x280 mm/slub.c:3238 __d_alloc+0x27/0x6d0 fs/dcache.c:1749 d_alloc_pseudo+0x19/0x70 fs/dcache.c:1880 alloc_file_pseudo+0xe0/0x200 fs/file_table.c:256 sock_alloc_file+0xb3/0x240 net/socket.c:464 __sys_socketpair+0x2cc/0x540 net/socket.c:1676 __do_sys_socketpair net/socket.c:1705 [inline] __se_sys_socketpair net/socket.c:1702 [inline] __x64_sys_socketpair+0x97/0xb0 net/socket.c:1702 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: 0033:0x7ff5dd84ae59 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:00007ff5dbaa4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000035 RAX: ffffffffffffffda RBX: 00007ff5ddac3fa0 RCX: 00007ff5dd84ae59 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000001 RBP: 00007ff5dd8e0e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000040 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff5ddac4038 R14: 00007ff5ddac3fa0 R15: 00007ffc1f854178