rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P64/1:b..l P5826/1:b..l P5834/1:b..l rcu: (detected by 1, t=10502 jiffies, g=14149, q=867 ncpus=2) task:syz-executor state:R running task stack:21512 pid:5834 tgid:5834 ppid:5824 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__module_address+0x14/0x3e0 kernel/module/main.c:3815 Code: 33 ff ff ff 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 41 57 41 56 41 55 41 54 53 48 3b 3d bc 71 16 0c <0f> 82 8a 02 00 00 48 3b 3d b7 71 16 0c 0f 87 7d 02 00 00 49 89 fd RSP: 0018:ffffc9000405f530 EFLAGS: 00000217 RAX: 0000000000000001 RBX: ffffffff81aaa4fd RCX: 31d75d98454c0500 RDX: 0000000000000000 RSI: ffffffff8bbf05c0 RDI: 00007f177ef90eba RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff81aaa4fd R10: dffffc0000000000 R11: ffffffff81ac2d30 R12: ffff88802e0d8000 R13: ffff88801a026640 R14: 00007f177ef90eba R15: 1ffff9200080bec6 __module_text_address kernel/module/main.c:3871 [inline] is_module_text_address+0x88/0x1e0 kernel/module/main.c:3846 kernel_text_address+0x94/0xe0 kernel/extable.c:119 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5642 [inline] __kvmalloc_node_noprof+0x5cd/0x910 mm/slub.c:7100 xt_jumpstack_alloc net/netfilter/x_tables.c:1356 [inline] xt_replace_table+0x18a/0x790 net/netfilter/x_tables.c:1395 __do_replace+0x15a/0x980 net/ipv6/netfilter/ip6_tables.c:1081 do_replace net/ipv6/netfilter/ip6_tables.c:1158 [inline] do_ip6t_set_ctl+0xa16/0xce0 net/ipv6/netfilter/ip6_tables.c:1644 nf_setsockopt+0x26f/0x290 net/netfilter/nf_sockopt.c:101 do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2360 __sys_setsockopt net/socket.c:2385 [inline] __do_sys_setsockopt net/socket.c:2391 [inline] __se_sys_setsockopt net/socket.c:2388 [inline] __x64_sys_setsockopt+0x13f/0x1b0 net/socket.c:2388 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f177ef90eba RSP: 002b:00007ffff68b8fe8 EFLAGS: 00000202 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007ffff68b9070 RCX: 00007f177ef90eba RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00000000000002e8 R09: 0079746972756365 R10: 00007f177f1b4140 R11: 0000000000000202 R12: 00007f177f1b40e0 R13: 00007ffff68b900c R14: 0000000000000000 R15: 00007f177f1b4e60 task:syz-executor state:R running task stack:21320 pid:5826 tgid:5826 ppid:5820 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:rcu_read_lock include/linux/rcupdate.h:868 [inline] RIP: 0010:is_bpf_text_address+0x66/0x2b0 kernel/bpf/core.c:744 Code: 48 89 44 24 08 50 e8 19 3e ce ff 48 83 c4 08 e8 f0 04 77 09 89 c5 31 ff 89 c6 e8 c5 f4 f0 ff 85 ed 74 10 e8 3c 3a d7 ff 84 c0 <74> 0e e8 73 f0 f0 ff eb 56 e8 6c f0 f0 ff eb 4f e8 c5 04 77 09 89 RSP: 0018:ffffc9000404f830 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 00007fe1f678dc2a RCX: ea0e57efda901100 RDX: ffff88802e1c1e40 RSI: ffffffff8bbf05c0 RDI: ffffffff8bbf0580 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff81cf13b6 R10: dffffc0000000000 R11: ffffffff81ac2d30 R12: ffff88802e1c1e40 R13: 0000000000000000 R14: 00007fe1f678dc2a R15: 1ffff92000809f22 kernel_text_address+0xa5/0xe0 kernel/extable.c:125 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:559 slab_free_hook mm/slub.c:2500 [inline] slab_free mm/slub.c:6630 [inline] kmem_cache_free+0x4a2/0x690 mm/slub.c:6740 sk_prot_free net/core/sock.c:2276 [inline] __sk_destruct+0x4d2/0x660 net/core/sock.c:2373 inet_release+0x144/0x190 net/ipv4/af_inet.c:437 __sock_release net/socket.c:662 [inline] sock_close+0xc3/0x240 net/socket.c:1455 __fput+0x44c/0xa70 fs/file_table.c:468 fput_close_sync+0x119/0x200 fs/file_table.c:573 __do_sys_close fs/open.c:1589 [inline] __se_sys_close fs/open.c:1574 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1574 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe1f678dc2a RSP: 002b:00007fffc75d1fc0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fe1f678dc2a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fffc75d201c R08: 00007fffc75d190c R09: 0079746972756365 R10: 00007fffc75d1970 R11: 0000000000000293 R12: 000000000000000c R13: 00000000000927c0 R14: 0000000000020972 R15: 00007fffc75d2070 task:kworker/u8:4 state:R running task stack:22728 pid:64 tgid:64 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: kvfree_rcu_reclaim kfree_rcu_work Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:114 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:128 [inline] RIP: 0010:lock_acquire+0xda/0x360 kernel/locking/lockdep.c:5864 Code: 6e 92 83 b8 2c 0b 00 00 00 0f 85 d5 00 00 00 48 c7 44 24 30 00 00 00 00 9c 8f 44 24 30 4c 89 74 24 10 4d 89 fe 4c 8b 7c 24 30 48 c7 c7 9a 02 72 8d e8 89 d9 a8 09 65 ff 05 92 0d d1 10 45 31 RSP: 0018:ffffc9000213f2b8 EFLAGS: 00000246 RAX: ffff88801c723c80 RBX: 0000000000000000 RCX: 1cbc87865d7b7200 RDX: 0000000000000000 RSI: ffffffff81738d42 RDI: 1ffffffff1be7a5c RBP: ffffffff81738d25 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff81ac2d30 R12: 0000000000000002 R13: ffffffff8df3d2e0 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2539 [inline] slab_free_freelist_hook mm/slub.c:2568 [inline] slab_free_bulk mm/slub.c:6662 [inline] kmem_cache_free_bulk+0xb0c/0xdb0 mm/slub.c:7346 kfree_bulk include/linux/slab.h:830 [inline] kvfree_rcu_bulk+0xe5/0x1f0 mm/slab_common.c:1522 kfree_rcu_work+0xed/0x170 mm/slab_common.c:1600 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 10470 jiffies! g14149 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27224 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 5e 33 ca f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 21 22 00 f3 0f 1e fa fb f4 33 33 ca f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8dc07d80 EFLAGS: 000002c6 RAX: 6801a949dc667000 RBX: ffffffff81967be7 RCX: 6801a949dc667000 RDX: 0000000000000001 RSI: ffffffff8d70bf53 RDI: ffffffff8bbf05e0 RBP: ffffffff8dc07ea8 R08: ffff8880b8832fdb R09: 1ffff110171065fb R10: dffffc0000000000 R11: ffffed10171065fc R12: ffffffff8f7cd470 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1b92a40 FS: 0000000000000000(0000) GS:ffff88812613e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1b7f582b47 CR3: 0000000078c13000 CR4: 0000000000350ef0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e7/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x3ae/0x410 init/main.c:1111 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147