rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3744/1:b..l (detected by 1, t=10502 jiffies, g=10065, q=77) task:kworker/u4:11 state:R running task stack:21080 pid: 3744 ppid: 2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6780 irqentry_exit+0x53/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lock_acquire+0x252/0x4f0 kernel/locking/lockdep.c:5627 Code: 2b 00 74 08 4c 89 f7 e8 cc 86 67 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0000:ffffc900030a78e0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000614f28 RCX: 1ffff92000614ec8 RDX: dffffc0000000000 RSI: ffffffff8a8b3ca0 RDI: ffffffff8ad8f800 RBP: ffffc900030a7a40 R08: dffffc0000000000 R09: fffffbfff1f8e019 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000614f24 R13: dffffc0000000000 R14: ffffc900030a7940 R15: 0000000000000246 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] inet_twsk_purge+0x129/0x9d0 net/ipv4/inet_timewait_sock.c:268 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x763/0xb60 net/core/net_namespace.c:599 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: rcu_preempt kthread starved for 10449 jiffies! g10065 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:27064 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4529 Comm: syz.2.172 Not tainted 5.15.164-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 RIP: 0010:kasan_check_range+0x1/0x290 mm/kasan/generic.c:188 Code: 01 c6 48 89 c7 e8 cf 7a 69 08 31 c0 c3 0f 0b b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 cc cc cc cc cc cc cc cc cc cc cc cc 55 <41> 57 41 56 53 b0 01 48 85 f6 0f 84 9a 01 00 00 48 89 fd 48 01 f5 RSP: 0018:ffffc900031179b0 EFLAGS: 00000046 RAX: 0000000000000006 RBX: 0000000000000199 RCX: ffffffff8162b7b9 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8fc700f0 RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1f8e01f R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: ffff888079ab0ae8 R14: 0000000000000003 R15: ffff888079ab0b10 FS: 0000555557318500(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc3d68f4000 CR3: 00000000646ad000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:71 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] hlock_class kernel/locking/lockdep.c:197 [inline] check_wait_context kernel/locking/lockdep.c:4687 [inline] __lock_acquire+0x549/0x1ff0 kernel/locking/lockdep.c:4962 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __might_fault+0xb4/0x110 mm/memory.c:5328 _copy_from_user+0x28/0x170 lib/usercopy.c:14 copy_from_user include/linux/uaccess.h:192 [inline] restore_sigcontext+0xce/0x710 arch/x86/kernel/signal.c:91 __do_sys_rt_sigreturn+0x190/0x250 arch/x86/kernel/signal.c:674 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fc3d8676319 Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25 RSP: 002b:00007ffe59c4fd40 EFLAGS: 00000206 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 00007fc3d8877208 RCX: 00007fc3d8676319 RDX: 00007ffe59c4fd40 RSI: 00007ffe59c4fe70 RDI: 0000000000000021 RBP: 00007fc3d8878a80 R08: 00000000005eeb40 R09: 0000000000000006 R10: 0000001b32820210 R11: 0000000000000206 R12: 000000000001a680 R13: 00007ffe59c50980 R14: 00007ffe59c509a0 R15: ffffffffffffffff vkms_vblank_simulate: vblank timer overrun vkms_vblank_simulate: vblank timer overrun hrtimer: interrupt took 863522346 ns vkms_vblank_simulate: vblank timer overrun