rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P29037/1:b..l rcu: (detected by 1, t=10502 jiffies, g=195049, q=105 ncpus=2) task:syz-executor state:R running task stack:21736 pid:29037 ppid:29023 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:815 [inline] RIP: 0010:is_bpf_text_address+0x1fb/0x2a0 kernel/bpf/core.c:743 Code: ff 4c 8b 24 24 8b 05 b4 73 4c 0b 44 39 e0 74 0a e8 ca a7 f2 ff e9 e4 fe ff ff e8 20 71 f2 08 89 c5 31 ff 89 c6 e8 65 ab f2 ff <85> ed 74 10 e8 8c 6a dc ff 84 c0 74 0e e8 a3 a7 f2 ff eb 56 e8 9c RSP: 0018:ffffc90004ccf588 EFLAGS: 00000293 RAX: ffffffff81947feb RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88801d6c9e00 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: dffffc0000000000 R09: 1ffffffff2238ea0 R10: dffffc0000000000 R11: fffffbfff2238ea1 R12: 0000000000000ba0 R13: dffffc0000000000 R14: 00007f878239e69a R15: 0000000000000000 kernel_text_address+0xa0/0xd0 kernel/extable.c:125 __kernel_text_address+0xd/0x30 kernel/extable.c:79 unwind_get_return_address+0x5d/0xc0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0x11d/0x190 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1e0 mm/slub.c:3843 xt_free_table_info+0xfc/0x170 net/netfilter/x_tables.c:1231 __do_replace+0x7ca/0x990 net/ipv6/netfilter/ip6_tables.c:1101 do_replace net/ipv6/netfilter/ip6_tables.c:1158 [inline] do_ip6t_set_ctl+0xb48/0xe10 net/ipv6/netfilter/ip6_tables.c:1644 nf_setsockopt+0x263/0x280 net/netfilter/nf_sockopt.c:101 do_sock_setsockopt+0x175/0x1a0 net/socket.c:2321 __sys_setsockopt net/socket.c:2344 [inline] __do_sys_setsockopt net/socket.c:2353 [inline] __se_sys_setsockopt net/socket.c:2350 [inline] __x64_sys_setsockopt+0x182/0x200 net/socket.c:2350 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f878239e69a RSP: 002b:00007ffc360da058 EFLAGS: 00000202 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007ffc360da0e0 RCX: 00007f878239e69a RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00000000000002e8 R09: 0000000000000000 R10: 00007f87825ea2a0 R11: 0000000000000202 R12: 00007f87825ea240 R13: 00007ffc360da07c R14: 0000000000000000 R15: 00007f87825eafc0 rcu: rcu_preempt kthread starved for 10551 jiffies! g195049 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:26728 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148 Code: b9 20 02 c3 cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d c3 54 41 00 fb f4 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2e 41 89 de 80 RSP: 0018:ffffc90000187de0 EFLAGS: 000002c6 RAX: cb9a37c5b9e3c100 RBX: ffffffff8162aee1 RCX: cb9a37c5b9e3c100 RDX: 0000000000000001 RSI: ffffffff8acacbe0 RDI: ffffffff8b1c9860 RBP: ffffc90000187f20 R08: ffff8880b8f36b2b R09: 1ffff110171e6d65 R10: dffffc0000000000 R11: ffffed10171e6d66 R12: 1ffff92000030fc8 R13: dffffc0000000000 R14: 1ffff110037cb780 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f62683ea540 CR3: 0000000075bbe000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:753 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97 cpuidle_idle_call kernel/sched/idle.c:178 [inline] do_idle+0x221/0x590 kernel/sched/idle.c:302 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401 start_secondary+0xee/0xf0 arch/x86/kernel/smpboot.c:323 secondary_startup_64_no_verify+0x179/0x17b