rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2963/1:b..l (detected by 1, t=10502 jiffies, g=4549, q=156) task:udevd state:R running task stack:25072 pid: 2963 ppid: 1 flags:0x00004002 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:bytes_is_nonzero mm/kasan/generic.c:84 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x68/0x290 mm/kasan/generic.c:189 Code: fc ff df 4e 8d 0c 03 4c 8d 54 37 ff 49 c1 ea 03 49 bb 01 00 00 00 00 fc ff df 4f 8d 34 1a 4c 89 f5 4c 29 cd 48 83 fd 10 7f 26 <48> 85 ed 0f 84 3a 01 00 00 49 f7 d2 49 01 da 41 80 39 00 0f 85 c4 RSP: 0018:ffffc90002db73d8 EFLAGS: 00000283 RAX: 0000000000000001 RBX: 1ffffffff1bc8d85 RCX: ffffffff8162a9bc RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8de46c28 RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff1bc8d85 R10: 1ffffffff1bc8d85 R11: dffffc0000000001 R12: 1ffff920005b6e88 R13: dffffc0000000000 R14: fffffbfff1bc8d86 R15: 1ffff920005b6ec4 instrument_atomic_read include/linux/instrumented.h:71 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] cpumask_test_cpu include/linux/cpumask.h:344 [inline] cpu_online include/linux/cpumask.h:895 [inline] trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0xcc/0x4f0 kernel/locking/lockdep.c:5594 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] dput+0x35/0x1a0 fs/dcache.c:875 step_into+0x352/0xe90 fs/namei.c:1815 walk_component+0x359/0x610 fs/namei.c:1982 link_path_walk+0x642/0xd90 path_openat+0x249/0x2f20 fs/namei.c:3738 do_filp_open+0x21c/0x460 fs/namei.c:3769 do_sys_openat2+0x13b/0x500 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1280 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: 0033:0x7fa71457e9a4 RSP: 002b:00007fff7d00eac0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fa71457e9a4 RDX: 0000000000080241 RSI: 00007fff7d00eef8 RDI: 00000000ffffff9c RBP: 00007fff7d00eef8 R08: 0000000000000004 R09: 0000000000000001 R10: 00000000000001b6 R11: 0000000000000246 R12: 0000000000080241 R13: 000055a7b3f9072e R14: 0000000000000001 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10529 jiffies! g4549 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:26816 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:300 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: 3601 Comm: syz.2.3 Not tainted 5.15.161-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:193 Code: 1f 84 00 00 00 00 00 0f 1f 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 98 13 64 0c 48 89 de 5b e9 47 f7 48 00 cc cc cc cc cc cc cc <48> 8b 04 24 65 48 8b 0d e4 14 82 7e 65 8b 15 e5 14 82 7e f7 c2 00 RSP: 0018:ffffc90000007c10 EFLAGS: 00000083 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffff88801ff88000 RDX: ffff88801ff88000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000007ce8 R08: ffffffff814fe45c R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: ffff88801af1cbe8 R13: dffffc0000000000 R14: ffffc90000007c80 R15: ffffc90000007c80 FS: 00007fa2058c16c0(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002006b000 CR3: 0000000062429000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 rcu_read_lock include/linux/rcupdate.h:739 [inline] send_sigqueue+0x10f/0x6e0 kernel/signal.c:1969 posix_timer_event kernel/time/posix-timers.c:359 [inline] posix_timer_fn+0x186/0x390 kernel/time/posix-timers.c:385 __run_hrtimer kernel/time/hrtimer.c:1686 [inline] __hrtimer_run_queues+0x598/0xcf0 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 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 80 f6 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 be 11 3b f7 48 89 df e8 96 65 3c f7 e8 b1 1d 5f f7 fb bf 01 00 00 00 d6 ab 2f f7 65 8b 05 57 b2 da 75 85 c0 74 02 5b c3 e8 24 cf d8 RSP: 0018:ffffc900030f7bc0 EFLAGS: 00000282 RAX: 820b6e27c972a100 RBX: ffff888065e15340 RCX: ffffffff913f0f03 RDX: dffffc0000000000 RSI: ffffffff8a8b2a00 RDI: 0000000000000001 RBP: 0000000000000000 R08: ffffffff8186db40 R09: ffffed100cbc2a69 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000021 R13: dffffc0000000000 R14: ffff888065e157d8 R15: ffff888065e15340 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:154 [inline] exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fa206e40bd9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa2058c1048 EFLAGS: 00000246 RAX: 0000000000000005 RBX: 00007fa206fcef60 RCX: 00007fa206e40bd9 RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00007fa206eafa98 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fa206fcef60 R15: 00007ffe80dfa698 sched: RT throttling activated