rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2949/1:b..l (detected by 1, t=10502 jiffies, g=321305, q=33) task:udevd state:R running task stack:22176 pid: 2949 ppid: 1 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5026 [inline] __schedule+0x12c4/0x4590 kernel/sched/core.c:6372 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6776 irqentry_exit+0x53/0x80 kernel/entry/common.c:426 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__kasan_check_read+0x0/0x10 mm/kasan/shadow.c:31 Code: d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 48 c7 c7 32 da 15 8c eb 0a 48 c7 c7 6a da 15 8c 4c 89 fe e8 0f ad 51 08 31 db eb d7 cc cc <89> f6 48 8b 0c 24 31 d2 e9 63 ef ff ff 0f 1f 00 89 f6 48 8b 0c 24 RSP: 0018:ffffc90002c7f7b0 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 1ffff9200001a252 RCX: ffff88807c8b8000 RDX: ffff88807c8b8000 RSI: 0000000000000008 RDI: ffffc900000d1290 RBP: 0000000000000001 R08: ffffffff81db9ef3 R09: fffffbfff1f7b021 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88801c8ff1e0 R13: ffff888075e402f0 R14: ffffc900000d1290 R15: dffffc0000000000 instrument_atomic_read include/linux/instrumented.h:71 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] bit_spin_is_locked include/linux/bit_spinlock.h:92 [inline] hlist_bl_is_locked include/linux/list_bl.h:158 [inline] hlist_bl_first_rcu include/linux/rculist_bl.h:24 [inline] __d_lookup+0x134/0x730 fs/dcache.c:2423 lookup_fast+0xdc/0x7b0 fs/namei.c:1617 walk_component+0x115/0x610 fs/namei.c:1968 link_path_walk+0x642/0xd90 path_lookupat+0xa9/0x450 fs/namei.c:2450 filename_lookup+0x230/0x5c0 fs/namei.c:2480 user_path_at_empty+0x40/0x180 fs/namei.c:2853 do_readlinkat+0x114/0x3a0 fs/stat.c:442 __do_sys_readlink fs/stat.c:475 [inline] __se_sys_readlink fs/stat.c:472 [inline] __x64_sys_readlink+0x7b/0x90 fs/stat.c:472 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fcfc9ac9d47 RSP: 002b:00007ffd22e61b68 EFLAGS: 00000246 ORIG_RAX: 0000000000000059 RAX: ffffffffffffffda RBX: 00007ffd22e61b78 RCX: 00007fcfc9ac9d47 RDX: 0000000000000400 RSI: 00007ffd22e61b78 RDI: 00007ffd22e62058 RBP: 0000000000000400 R08: 000055df0b7915a4 R09: 0000000000000000 R10: 0000000000000812 R11: 0000000000000246 R12: 00007ffd22e62058 R13: 00007ffd22e61fc8 R14: 000055df0b70c910 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10533 jiffies! g321305 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:26936 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5026 [inline] __schedule+0x12c4/0x4590 kernel/sched/core.c:6372 schedule+0x11b/0x1f0 kernel/sched/core.c:6455 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1884 rcu_gp_fqs_loop+0x2af/0xf70 kernel/rcu/tree.c:1959 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2132 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 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: 22278 Comm: syz-executor.2 Not tainted 5.15.128-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline] RIP: 0010:static_key_false include/linux/jump_label.h:212 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:156 [inline] RIP: 0010:wrmsr arch/x86/include/asm/msr.h:263 [inline] RIP: 0010:native_apic_msr_write+0x35/0x50 arch/x86/include/asm/apic.h:207 Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 89 f6 31 d2 e9 cf b2 f1 02 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc90000007e60 EFLAGS: 00000046 RAX: 0000000000041d74 RBX: ffffffff8c3509a8 RCX: 0000000000000838 RDX: 0000000000000000 RSI: 0000000000041d74 RDI: 0000000000000838 RBP: 0000000000041d74 R08: ffffffff81723d4d R09: fffffbfff1bc8156 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880b9a27240 R13: dffffc0000000000 R14: 0000000000041d74 R15: dffffc0000000000 FS: 00007f8c143ab6c0(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8c143aad00 CR3: 0000000081b3e000 CR4: 00000000003506f0 Call Trace: apic_write arch/x86/include/asm/apic.h:394 [inline] lapic_next_event+0x5b/0x70 arch/x86/kernel/apic/apic.c:468 clockevents_program_event+0x1c5/0x310 kernel/time/clockevents.c:334 hrtimer_interrupt+0x546/0x980 kernel/time/hrtimer.c:1824 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: 21 7e f6 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 2e 98 3c f7 48 89 df e8 86 eb 3d f7 e8 11 80 60 f7 fb bf 01 00 00 00 46 28 31 f7 65 8b 05 27 65 dc 75 85 c0 74 02 5b c3 e8 b4 7c da RSP: 0018:ffffc90003f0fbc0 EFLAGS: 00000282 RAX: dbf067fddbc20200 RBX: ffff88807657b780 RCX: ffffffff913d0003 RDX: dffffc0000000000 RSI: ffffffff8a8b0ce0 RDI: 0000000000000001 RBP: 0000000000000000 R08: ffffffff81868ad0 R09: ffffed100ecaf6f1 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000021 R13: dffffc0000000000 R14: ffff88807657bc18 R15: ffff88807657b780 spin_unlock_irq include/linux/spinlock.h:413 [inline] get_signal+0x13ee/0x14e0 kernel/signal.c:2892 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:172 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x5d/0x250 kernel/entry/common.c:301 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f8c15e29ae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8c143ab0c8 EFLAGS: 00000246 RAX: 000000000000000b RBX: 00007f8c15f48f80 RCX: 00007f8c15e29ae9 RDX: 0000000000000318 RSI: 00000000200bd000 RDI: 0000000000000004 RBP: 00007f8c15e7547a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f8c15f48f80 R15: 00007ffeeaecaad8