rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-....: (1 GPs behind) idle=28b/1/0x4000000000000002 softirq=27747/27748 fqs=2111 (detected by 1, t=10505 jiffies, g=39553, q=1433) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 10870 Comm: syz.6.1493 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] 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+0xc/0x80 kernel/kcov.c:300 Code: 44 02 08 05 00 00 00 4a 89 7c 02 10 4a 89 74 02 18 4a 89 44 02 20 48 ff c1 48 89 0a c3 90 48 8b 04 24 65 48 8b 0d 24 6f 89 7e <65> 8b 15 25 6f 89 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 RSP: 0018:ffffc90000007038 EFLAGS: 00000002 RAX: ffffffff8197c0a9 RBX: ffffc900000071e0 RCX: ffff888026550000 RDX: 0000000000000100 RSI: 0000000000000020 RDI: ffffffffffffffff RBP: ffffc90000007130 R08: ffffc900000071b7 R09: ffffc90000007180 R10: dffffc0000000000 R11: fffff52000000e37 R12: dffffc0000000000 R13: ffffc900000071e6 R14: 0000000000000020 R15: ffffc90000007340 FS: 00007f473e5de6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000035000 CR3: 000000005d8f1000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: perf_prepare_sample+0x1e9/0x1cb0 kernel/events/core.c:7632 __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 02 20 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:ffffc90000007780 EFLAGS: 00000206 RAX: a91955ccdc2cef00 RBX: 1ffff92000000ef4 RCX: a91955ccdc2cef00 RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a4200 RBP: ffffc90000007860 R08: ffffffff901ee1c7 R09: 1ffffffff203dc38 R10: dffffc0000000000 R11: fffffbfff203dc39 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] ndisc_send_skb+0xd39/0x1410 net/ipv6/ndisc.c:521 addrconf_rs_timer+0x367/0x640 net/ipv6/addrconf.c:3966 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:check_region_inline mm/kasan/generic.c:-1 [inline] RIP: 0010:kasan_check_range+0xc/0x290 mm/kasan/generic.c:189 Code: c0 c3 0f 0b b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 00 00 cc cc 00 00 cc cc 00 00 cc cc b0 01 48 85 f6 0f 84 ac 01 00 00 55 <41> 57 41 56 41 54 53 49 89 f8 49 01 f0 0f 82 0e 02 00 00 49 89 f8 RSP: 0018:ffffc900040df590 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff815d5bc4 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8d8b0de8 RBP: ffffc900040df6b0 R08: dffffc0000000000 R09: 1ffffffff203dc18 R10: dffffc0000000000 R11: fffffbfff203dc19 R12: 1ffff9200081bec0 R13: dffffc0000000000 R14: 1ffff11017206c94 R15: 0000000000000bd0 instrument_atomic_read include/linux/instrumented.h:71 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] cpumask_test_cpu include/linux/cpumask.h:344 [inline] cpu_online include/linux/cpumask.h:895 [inline] trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0xa4/0x8a0 kernel/locking/lockdep.c:5634 css_put include/linux/cgroup.h:405 [inline] obj_cgroup_uncharge_pages mm/memcontrol.c:2998 [inline] drain_obj_stock+0xc7/0x360 mm/memcontrol.c:3176 refill_obj_stock+0x11d/0x470 mm/memcontrol.c:3242 obj_cgroup_charge+0x1c3/0x320 mm/memcontrol.c:3301 memcg_slab_pre_alloc_hook mm/slab.h:287 [inline] slab_pre_alloc_hook+0x9d/0xc0 mm/slab.h:497 slab_alloc_node mm/slub.c:3139 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x3d/0x280 mm/slub.c:3238 kmem_cache_zalloc include/linux/slab.h:728 [inline] __alloc_file+0x25/0x240 fs/file_table.c:132 alloc_empty_file+0x90/0x180 fs/file_table.c:181 path_openat+0x11c/0x2fb0 fs/namei.c:3736 do_filp_open+0x1df/0x400 fs/namei.c:3777 do_sys_openat2+0x14b/0x500 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 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: 0033:0x7f47403860d9 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:00007f473e5de028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f474060dfa0 RCX: 00007f47403860d9 RDX: 0000000000000002 RSI: 0000200000000180 RDI: ffffffffffffffff RBP: 00007f474041d024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f474060e038 R14: 00007f474060dfa0 R15: 00007fffc96b52e8