rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3561/1:b..l P4189/1:b..l (detected by 0, t=10502 jiffies, g=30085, q=162) task:syz-executor state:R running task stack:21840 pid: 4189 ppid: 4181 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04 RSP: 0018:ffffc90002d5f6a0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: d13f295cd670bb00 RDX: 0000000000000000 RSI: ffffffff8a2b3a20 RDI: ffffffff8a79f980 RBP: ffffc90002d5f7b0 R08: dffffc0000000000 R09: 1ffffffff203a818 R10: dffffc0000000000 R11: fffffbfff203a819 R12: ffffffff8c31eaa0 R13: 1ffff920005abee0 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire+0x20/0x30 include/linux/rcupdate.h:313 rcu_read_lock include/linux/rcupdate.h:740 [inline] get_obj_cgroup_from_current+0xd1/0x2f0 mm/memcontrol.c:2922 memcg_slab_pre_alloc_hook mm/slab.h:283 [inline] slab_pre_alloc_hook+0x7e/0xc0 mm/slab.h:497 slab_alloc_node mm/slub.c:3139 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x3d/0x290 mm/slub.c:3238 anon_vma_chain_alloc mm/rmap.c:138 [inline] anon_vma_clone+0xbd/0x4f0 mm/rmap.c:284 anon_vma_fork+0x7e/0x500 mm/rmap.c:347 dup_mmap kernel/fork.c:574 [inline] dup_mm kernel/fork.c:1466 [inline] copy_mm+0xa06/0x13f0 kernel/fork.c:1518 copy_process+0x17eb/0x3e20 kernel/fork.c:2290 kernel_clone+0x23f/0x990 kernel/fork.c:2679 __do_sys_clone kernel/fork.c:2796 [inline] __se_sys_clone kernel/fork.c:2780 [inline] __x64_sys_clone+0x19a/0x210 kernel/fork.c:2780 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: 0033:0x7f61c1f91212 RSP: 002b:00007ffc945f8700 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffc945f8700 RCX: 00007f61c1f91212 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffc945f888c R08: 0000000000000000 R09: 0000000000000001 R10: 000055558cf087d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 000000000004796c R15: 00007ffc945f88e0 task:udevd state:R running task stack:23120 pid: 3561 ppid: 1 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6571 preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6596 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0x10d/0x120 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:419 [inline] __wake_up_common_lock kernel/sched/wait.c:140 [inline] __wake_up_sync_key+0x128/0x190 kernel/sched/wait.c:205 sock_def_readable+0x136/0x250 net/core/sock.c:3101 __netlink_sendskb net/netlink/af_netlink.c:1264 [inline] netlink_sendskb+0x97/0x130 net/netlink/af_netlink.c:1270 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2499 __sys_sendmsg net/socket.c:2528 [inline] __do_sys_sendmsg net/socket.c:2537 [inline] __se_sys_sendmsg+0x1af/0x290 net/socket.c:2535 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: 0033:0x7f655cc77407 RSP: 002b:00007ffed1968970 EFLAGS: 00000202 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f655cb89880 RCX: 00007f655cc77407 RDX: 0000000000000000 RSI: 00007ffed19689d0 RDI: 0000000000000004 RBP: 000055edb7708510 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000000b4 R13: 000055edb77089e0 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 9907 jiffies! g30085 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:28016 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:729 sched: RT throttling activated