rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5960/1:b..l rcu: (detected by 0, t=10502 jiffies, g=14237, q=648 ncpus=2) task:syz-executor state:R running task stack:19496 pid:5960 tgid:5960 ppid:5958 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:unwind_next_frame+0x86e/0x23d0 arch/x86/kernel/unwind_orc.c:532 Code: 0f 84 48 0f 00 00 48 83 c7 10 e9 73 01 00 00 83 fb 04 0f 84 7b 01 00 00 83 fb 05 0f 85 38 0c 00 00 48 8b 44 24 58 80 3c 28 00 <74> 11 4c 89 ff e8 f8 ed b3 00 48 8b 34 24 48 8b 54 24 08 4d 8b 27 RSP: 0018:ffffc900046cf458 EFLAGS: 00000246 RAX: 1ffff920008d9eac RBX: 0000000000000005 RCX: ffffffff8fd57264 RDX: ffffffff904e9df2 RSI: ffffffff904e9df6 RDI: ffffffff8be24380 RBP: dffffc0000000000 R08: 0000000000000022 R09: ffffffff8e33f8a0 R10: ffffc900046cf578 R11: ffffffff81addf20 R12: ffffffff904e9df7 R13: ffffc900046cf578 R14: ffffc900046cf528 R15: ffffc900046cf560 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:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5661 [inline] __kvmalloc_node_noprof+0x5d5/0x920 mm/slub.c:7140 translate_table+0x19b/0x2040 net/ipv6/netfilter/ip6_tables.c:695 do_replace net/ipv6/netfilter/ip6_tables.c:1154 [inline] do_ip6t_set_ctl+0x970/0xce0 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:2337 __sys_setsockopt net/socket.c:2362 [inline] __do_sys_setsockopt net/socket.c:2368 [inline] __se_sys_setsockopt net/socket.c:2365 [inline] __x64_sys_setsockopt+0x13f/0x1b0 net/socket.c:2365 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f852939163a RSP: 002b:00007ffd35c31438 EFLAGS: 00000202 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007ffd35c314c0 RCX: 00007f852939163a RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00000000000003b8 R09: 0079746972756365 R10: 00007f85295b7800 R11: 0000000000000202 R12: 00007f85295b77a0 R13: 00007ffd35c3145c R14: 0000000000000000 R15: 00007f85295b7e60 rcu: rcu_preempt kthread starved for 10544 jiffies! g14237 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:27440 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 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+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc 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 be 21 00 f3 0f 1e fa fb f4 48 ee 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0000:ffffc90000197de0 EFLAGS: 000002c6 RAX: 288b57c71990ef00 RBX: ffffffff8197c88a RCX: 288b57c71990ef00 RDX: 0000000000000001 RSI: ffffffff8daa76bd RDI: ffffffff8be243e0 RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8fc3b070 R13: 1ffff11003adcb70 R14: 0000000000000001 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125ae1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7fba5572c0 CR3: 00000000325cc000 CR4: 00000000003526f0 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:191 [inline] do_idle+0x1ea/0x520 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147