rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4299/1:b..l (detected by 1, t=10502 jiffies, g=4969, q=276 ncpus=2) task:syz-executor316 state:R running task stack:0 pid:4299 ppid:4292 flags:0x00000004 Call trace: __switch_to+0x2f4/0x568 arch/arm64/kernel/process.c:555 context_switch kernel/sched/core.c:5244 [inline] __schedule+0xdd4/0x1b2c kernel/sched/core.c:6561 preempt_schedule_irq+0x8c/0x1b8 kernel/sched/core.c:6873 arm64_preempt_schedule_irq+0x44/0x58 arch/arm64/kernel/entry-common.c:265 __el1_irq arch/arm64/kernel/entry-common.c:474 [inline] el1_interrupt+0x3c/0x54 arch/arm64/kernel/entry-common.c:486 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:581 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline] lock_acquire+0x24c/0x644 kernel/locking/lockdep.c:5665 rcu_lock_acquire+0x40/0x4c include/linux/rcupdate.h:350 rcu_read_lock include/linux/rcupdate.h:791 [inline] net_generic+0x28/0x240 include/net/netns/generic.h:45 xt_find_table_lock+0x4c/0x394 net/netfilter/x_tables.c:1237 xt_request_find_table_lock+0x38/0x114 net/netfilter/x_tables.c:1284 get_info net/ipv6/netfilter/ip6_tables.c:981 [inline] do_ip6t_get_ctl+0x6d0/0x1314 net/ipv6/netfilter/ip6_tables.c:1670 nf_getsockopt+0x264/0x284 net/netfilter/nf_sockopt.c:116 ipv6_getsockopt+0x2bc/0x3e4 net/ipv6/ipv6_sockglue.c:1512 tcp_getsockopt+0xcc/0xe8 net/ipv4/tcp.c:4469 sock_common_getsockopt+0xa8/0xc4 net/core/sock.c:3655 __sys_getsockopt+0x1e0/0x480 net/socket.c:2332 __do_sys_getsockopt net/socket.c:2347 [inline] __se_sys_getsockopt net/socket.c:2344 [inline] __arm64_sys_getsockopt+0xb8/0xd4 net/socket.c:2344 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 rcu: rcu_preempt kthread starved for 10506 jiffies! g4969 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:0 pid:16 ppid:2 flags:0x00000008 Call trace: __switch_to+0x2f4/0x568 arch/arm64/kernel/process.c:555 context_switch kernel/sched/core.c:5244 [inline] __schedule+0xdd4/0x1b2c kernel/sched/core.c:6561 schedule+0xc4/0x170 kernel/sched/core.c:6637 schedule_timeout+0x180/0x2c8 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2a8/0x134c kernel/rcu/tree.c:1706 rcu_gp_kthread+0xc0/0x2f8 kernel/rcu/tree.c:1905 kthread+0x250/0x2d8 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864 rcu: Stack dump where RCU GP kthread last ran: Task dump for CPU 0: task:syz-executor316 state:R running task stack:0 pid:4372 ppid:4296 flags:0x00000001 Call trace: __switch_to+0x2f4/0x568 arch/arm64/kernel/process.c:555 0xffff0000c9e6a61c