rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3560/1:b..l P4363/1:b..l (detected by 0, t=10502 jiffies, g=11081, q=93) task:syz-executor state:R running task stack:21752 pid: 4363 ppid: 4349 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:check_kcov_mode kernel/kcov.c:174 [inline] RIP: 0010:write_comp_data kernel/kcov.c:227 [inline] RIP: 0010:__sanitizer_cov_trace_cmp8+0x2c/0x80 kernel/kcov.c:273 Code: 04 24 65 48 8b 0d 44 39 89 7e 65 8b 15 45 39 89 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 57 83 b9 34 16 00 00 00 74 4e <8b> 91 10 16 00 00 83 fa 03 75 43 48 8b 91 18 16 00 00 44 8b 89 14 RSP: 0018:ffffc900031df760 EFLAGS: 00000246 RAX: ffffffff84095bdc RBX: 1ffff9200063bf0e RCX: ffff88802b991dc0 RDX: 0000000000000000 RSI: 0000000000000013 RDI: 0000000000000013 RBP: ffffc900031df872 R08: ffff88802b991dc0 R09: 0000000000000002 R10: 0000000000000003 R11: 0000000000000000 R12: ffffc900031df878 R13: 0000000000000f53 R14: 0000000000000013 R15: 0000000000000013 xas_find+0x2bc/0xab0 lib/xarray.c:1253 find_get_entry mm/filemap.c:1978 [inline] find_lock_entries+0x19e/0xd70 mm/filemap.c:2092 shmem_undo_range+0x29a/0x1930 mm/shmem.c:943 shmem_truncate_range mm/shmem.c:1063 [inline] shmem_evict_inode+0x220/0xa40 mm/shmem.c:1145 evict+0x4c9/0x8d0 fs/inode.c:647 do_unlinkat+0x3e7/0x710 fs/namei.c:4363 __do_sys_unlink fs/namei.c:4404 [inline] __se_sys_unlink fs/namei.c:4402 [inline] __x64_sys_unlink+0x45/0x50 fs/namei.c:4402 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: 0033:0x7fea986c4f47 RSP: 002b:00007ffc073c50c8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fea986c4f47 RDX: 00007ffc073c50f0 RSI: 00007ffc073c5180 RDI: 00007ffc073c5180 RBP: 00007ffc073c5180 R08: 00007ffc073c6180 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffc073c6210 R13: 00007fea9875b1ca R14: 0000000000020716 R15: 00007ffc073c6250 task:udevd state:R running task stack:24944 pid: 3560 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: 0033:0x7f4ce443d407 RSP: 002b:00007ffde6840e10 EFLAGS: 00000202 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f4ce434f880 RCX: 00007f4ce443d407 RDX: 0000000000000000 RSI: 00007ffde6840e70 RDI: 0000000000000004 RBP: 0000559ee0c0bf90 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000000b4 R13: 0000559ee0be79e0 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10509 jiffies! g11081 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:27120 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