rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4277/1:b..l (detected by 1, t=10502 jiffies, g=7857, q=227) task:udevd state:R running task stack:25336 pid: 4277 ppid: 3546 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5029 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6779 irqentry_exit+0x53/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:PageSwapBacked include/linux/page-flags.h:-1 [inline] RIP: 0010:PageSwapCache include/linux/page-flags.h:415 [inline] RIP: 0010:page_index include/linux/mm.h:1666 [inline] RIP: 0010:thp_contains+0x146/0x3c0 include/linux/pagemap.h:452 Code: 08 48 89 ef e8 0b a3 21 00 48 8b 6d 00 48 c7 c7 ff ff ff ff 48 89 ee e8 88 b4 d7 ff 48 b8 00 00 00 00 00 fc ff df 80 3c 03 00 <74> 08 4c 89 e7 e8 e0 a2 21 00 4d 8b 24 24 44 89 e3 83 e3 01 31 ff RSP: 0018:ffffc900033cf678 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 1ffffd40002f4491 RCX: ffff888018991dc0 RDX: 0000000000000000 RSI: 00fff0000008001f RDI: ffffffffffffffff RBP: 00fff0000008001f R08: ffffffff81a8ec18 R09: fffff940002f4491 R10: 0000000000000000 R11: dffffc0000000001 R12: ffffea00017a2488 R13: ffffea00017a2480 R14: ffffea00017a2480 R15: ffffea00017a2488 find_lock_entries+0xa6d/0x1030 mm/filemap.c:2106 shmem_undo_range+0x2a3/0x1b50 mm/shmem.c:943 shmem_truncate_range mm/shmem.c:1063 [inline] shmem_evict_inode+0x21b/0xa00 mm/shmem.c:1145 evict+0x529/0x930 fs/inode.c:647 __dentry_kill+0x436/0x650 fs/dcache.c:586 dentry_kill+0xbb/0x290 fs/dcache.c:-1 dput+0xd8/0x1a0 fs/dcache.c:893 __fput+0x636/0x8e0 fs/file_table.c:319 task_work_run+0x129/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181 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: 0033:0x7f59d6ddb0a8 RSP: 002b:00007ffd4d07e178 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 00007f59d6cafae0 RCX: 00007f59d6ddb0a8 RDX: 0000555bccc50645 RSI: 00007ffd4d07d978 RDI: 0000000000000008 RBP: 0000555e992a1020 R08: 0000000000000006 R09: 8acb472437cf1e7c R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000002 R13: 0000555e992a4b50 R14: 0000000000000008 R15: 0000555e9928f910 rcu: rcu_preempt kthread starved for 10497 jiffies! g7857 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:26168 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5029 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375 schedule+0x11b/0x1f0 kernel/sched/core.c:6458 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: 4409 Comm: syz.1.19 Not tainted 5.15.179-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:get_current kernel/locking/lockdep.c:6457 [inline] RIP: 0010:debug_check_no_locks_held+0x0/0x50 kernel/locking/lockdep.c:6458 Code: f9 80 e1 07 80 c1 03 38 c1 0f 8c ef fe ff ff e8 36 56 67 00 e9 e5 fe ff ff e8 6c c6 dc 08 66 2e 0f 1f 84 00 00 00 00 00 66 90 <53> 65 48 8b 1d d7 36 9f 7e 48 81 c3 e8 0a 00 00 48 89 d8 48 c1 e8 RSP: 0018:ffffc9000347fbc8 EFLAGS: 00000246 RAX: ffffffff81504813 RBX: 0000000000400140 RCX: 0000000000080000 RDX: ffffc9000f5cf000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: 0000000000000000 R08: ffffffff8150480a R09: ffffc9000347fde0 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888021a21a00 R13: dffffc0000000000 R14: ffff8880208d1dc0 R15: ffff888062571280 FS: 00007fd9e68ac6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5b7280e000 CR3: 0000000077c75000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: try_to_freeze include/linux/freezer.h:66 [inline] get_signal+0x108/0x14e0 kernel/signal.c:2694 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: 0033:0x7fd9e8a85167 Code: ff ff 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 RSP: 002b:00007fd9e68ac0e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007fd9e8c9e168 RCX: 00007fd9e8a85169 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fd9e8c9e168 RBP: 00007fd9e8c9e160 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd9e8c9e16c R13: 0000000000000000 R14: 00007ffe520c47e0 R15: 00007ffe520c48c8 sched: RT throttling activated