rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5924/1:b..l P4971/1:b..l P5628/1:b..l rcu: (detected by 0, t=20013 jiffies, g=156037, q=37 ncpus=1) task:syz-executor state:R running task stack:22232 pid:5628 tgid:5628 ppid:5604 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7413 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] copy_pte_range mm/memory.c:1347 [inline] copy_pmd_range+0x4e08/0x5880 mm/memory.c:1408 copy_pud_range mm/memory.c:1445 [inline] copy_p4d_range mm/memory.c:1469 [inline] copy_page_range+0xc26/0x1250 mm/memory.c:1555 dup_mmap+0xf21/0x1d90 mm/mmap.c:1840 dup_mm kernel/fork.c:1543 [inline] copy_mm+0x11a/0x480 kernel/fork.c:1595 copy_process+0x1e3e/0x4390 kernel/fork.c:2289 kernel_clone+0x2d7/0x940 kernel/fork.c:2748 __do_sys_clone kernel/fork.c:2889 [inline] __se_sys_clone kernel/fork.c:2873 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2873 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa6997c6b52 RSP: 002b:00007ffe84297010 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffe84297010 RCX: 00007fa6997c6b52 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffe8429719c R08: 0000000000000000 R09: 0000000000000001 R10: 000055558534f7d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 00000000000c4218 R15: 00007ffe842971f0 task:udevd state:R running task stack:22440 pid:4971 tgid:4971 ppid:1 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872 Code: ff ff ff e8 51 fd 2d 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 db f7 c9 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 ab 88 6d ff cc 48 8d 3d e8 1e b8 RSP: 0018:ffffc90003367a68 EFLAGS: 00000282 RAX: 329d46a65424ef00 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 000000005a44979c RSI: ffffffff8e4adf3a RDI: ffffffff8c4bbf80 RBP: ffffffff824e073e R08: ffffffff824e073e R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb59c60 R12: 0000000000000002 R13: ffffffff8eb59c60 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] fast_dput+0x3b/0x670 fs/dcache.c:938 dput+0x30/0x60 fs/dcache.c:1040 path_put fs/namei.c:722 [inline] terminate_walk+0xb5/0x4c0 fs/namei.c:849 path_lookupat+0x74f/0x8c0 fs/namei.c:2830 filename_lookup+0x265/0x5d0 fs/namei.c:2842 do_readlinkat+0xe3/0x510 fs/stat.c:571 __do_sys_readlink fs/stat.c:605 [inline] __se_sys_readlink fs/stat.c:602 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:602 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5cfa5153a7 RSP: 002b:00007ffcd6b40ce8 EFLAGS: 00000206 ORIG_RAX: 0000000000000059 RAX: ffffffffffffffda RBX: 00007ffcd6b40ef0 RCX: 00007f5cfa5153a7 RDX: 0000000000000200 RSI: 00007ffcd6b40cf0 RDI: 00007ffcd6b40ef0 RBP: 00005559e8511910 R08: 0000000000000064 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffcd6b40cf0 R13: 00005559d351b100 R14: 0000000000000000 R15: 00007ffcd6b41530 task:udevd state:R running task stack:23400 pid:5924 tgid:5924 ppid:4971 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:unwind_next_frame+0xd09/0x2550 arch/x86/kernel/unwind_orc.c:645 Code: 18 74 08 48 89 df e8 a6 0f bd 00 48 8b 04 24 48 89 03 ba 10 00 00 00 49 8d 5e 50 48 89 df 31 f6 e8 6c 11 bd 00 48 8b 54 24 08 c7 04 00 00 48 89 5c 24 48 49 8d 7e 08 48 89 fb 48 c1 eb 03 42 RSP: 0018:ffffc900054f7180 EFLAGS: 00000202 RAX: ffffc900054f7278 RBX: ffffc900054f7278 RCX: 0000000000000000 RDX: ffffffff9198b296 RSI: 0000000000000000 RDI: ffffc900054f7288 RBP: 1ffffffff2331652 R08: ffffc900054f7287 R09: ffffc900054f7278 R10: dffffc0000000000 R11: fffff52000a9ee51 R12: dffffc0000000000 R13: ffffffff9198b292 R14: ffffc900054f7228 R15: ffffc900054f7270 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __set_page_owner+0x8d/0x4c0 mm/page_owner.c:341 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0x21fa/0x2270 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3266 [inline] allocate_slab+0x79/0x5e0 mm/slub.c:3380 new_slab mm/slub.c:3426 [inline] refill_objects+0x2d5/0x350 mm/slub.c:7310 refill_sheaf mm/slub.c:2804 [inline] __pcs_replace_empty_main+0x2bf/0x6b0 mm/slub.c:4675 alloc_from_pcs mm/slub.c:4773 [inline] slab_alloc_node mm/slub.c:4905 [inline] __do_kmalloc_node mm/slub.c:5333 [inline] __kmalloc_noprof+0x485/0x720 mm/slub.c:5359 _kmalloc_noprof include/linux/slab.h:992 [inline] tomoyo_realpath_from_path+0xef/0x640 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x283/0x560 security/tomoyo/file.c:827 security_inode_getattr+0x12b/0x310 security/security.c:1895 vfs_getattr fs/stat.c:259 [inline] vfs_fstat fs/stat.c:281 [inline] __do_sys_newfstat fs/stat.c:551 [inline] __se_sys_newfstat fs/stat.c:546 [inline] __x64_sys_newfstat+0x133/0x270 fs/stat.c:546 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5cfa511ad7 RSP: 002b:00007ffcd6b40508 EFLAGS: 00000297 ORIG_RAX: 0000000000000005 RAX: ffffffffffffffda RBX: 00005559e8542f40 RCX: 00007f5cfa511ad7 RDX: 00007f5cfa5efea0 RSI: 00007ffcd6b40510 RDI: 0000000000000009 RBP: 00007f5cfa5efff0 R08: 0000000000000073 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000297 R12: 00007ffcd6b406e0 R13: 00007f5cfa5efff0 R14: 0000000000000017 R15: 00005559d35049dd rcu: rcu_preempt kthread timer wakeup didn't happen for 20012 jiffies! g156037 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=65511 rcu: rcu_preempt kthread starved for 20013 jiffies! g156037 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27656 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 21405 Comm: syz.8.5988 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:queue_work_on+0x162/0x1d0 kernel/workqueue.c:2457 Code: 00 4d 85 ed 75 16 e8 ed 34 39 00 eb 15 e8 e6 34 39 00 e8 01 e9 42 0a 4d 85 ed 74 ea e8 d7 34 39 00 fb 65 48 8b 05 8e e3 de 11 <48> 3b 44 24 18 75 56 89 d8 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc90007407b88 EFLAGS: 00000287 RAX: 625dfcd371c26e00 RBX: ffffffff8eb84601 RCX: 0000000000080000 RDX: ffffc90017003000 RSI: 0000000000000177 RDI: 0000000000000178 RBP: 0000000000000008 R08: ffffffff90574837 R09: 1ffffffff20ae906 R10: dffffc0000000000 R11: fffffbfff20ae907 R12: 0000000000000000 R13: 0000000000000200 R14: 0000000000000000 R15: 0000000000800011 FS: 00007f10151e86c0(0000) GS:ffff888124f55000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3301eff8 CR3: 00000000773ef000 CR4: 0000000000350ef0 Call Trace: do_adjtimex+0x29d/0x370 kernel/time/timekeeping.c:3008 do_clock_adjtime kernel/time/posix-timers.c:1169 [inline] __do_sys_clock_adjtime kernel/time/posix-timers.c:1181 [inline] __se_sys_clock_adjtime kernel/time/posix-timers.c:1172 [inline] __x64_sys_clock_adjtime+0x252/0x340 kernel/time/posix-timers.c:1172 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f101439e0d9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f10151e8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007f1014625fa0 RCX: 00007f101439e0d9 RDX: 0000000000000000 RSI: 0000200000000380 RDI: 0000000000000000 RBP: 00007f1014435024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1014626038 R14: 00007f1014625fa0 R15: 00007ffc9221d998