rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7169/1:b..l P7470/1:b..l (detected by 1, t=10502 jiffies, g=62385, q=221) task:udevd state:R running task stack:22672 pid: 7470 ppid: 3560 flags:0x00004002 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:seqcount_lockdep_reader_access+0x195/0x1d0 include/linux/seqlock.h:106 Code: ff 4d 85 ed 75 16 e8 1a 6f ac ff eb 15 e8 13 6f ac ff e8 2e 04 f0 07 4d 85 ed 74 ea e8 04 6f ac ff fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 43 c7 44 27 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc90004797700 EFLAGS: 00000293 RAX: ffffffff81ccc58c RBX: 0000000000000000 RCX: ffff88802a1a5940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900047977b0 R08: ffffffff8d89f02f R09: 1ffffffff1b13e05 R10: dffffc0000000000 R11: fffffbfff1b13e06 R12: dffffc0000000000 R13: 0000000000000200 R14: ffffffff81ccd402 R15: 1ffff920008f2ee0 __follow_mount_rcu fs/namei.c:1465 [inline] handle_mounts fs/namei.c:1498 [inline] step_into+0x652/0xd10 fs/namei.c:1814 link_path_walk+0x665/0xd70 fs/namei.c:-1 path_lookupat+0x9d/0x440 fs/namei.c:2462 filename_lookup+0x214/0x540 fs/namei.c:2492 user_path_at_empty+0x40/0x190 fs/namei.c:2891 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0x107/0x500 fs/stat.c:221 vfs_fstatat fs/stat.c:243 [inline] __do_sys_newfstatat fs/stat.c:411 [inline] __se_sys_newfstatat fs/stat.c:405 [inline] __x64_sys_newfstatat+0x15f/0x200 fs/stat.c:405 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: 0033:0x7fce3d1e4b0a RSP: 002b:00007ffe1c4613e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 000055601ed04fa0 RCX: 00007fce3d1e4b0a RDX: 00007ffe1c461410 RSI: 000055601ed04fa0 RDI: 00000000ffffff9c RBP: 000055601ed04fb9 R08: 0000000000006e40 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffe1c462535 R13: 00007ffe1c4614a0 R14: 0000555fef9586d7 R15: 00007ffe1c462530 task:udevd state:R running task stack:23120 pid: 7169 ppid: 3560 flags:0x00004002 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:seqcount_lockdep_reader_access+0x195/0x1d0 include/linux/seqlock.h:106 Code: ff 4d 85 ed 75 16 e8 6a 73 a2 ff eb 15 e8 63 73 a2 ff e8 7e 08 e6 07 4d 85 ed 74 ea e8 54 73 a2 ff fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 43 c7 44 27 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc90005f4f720 EFLAGS: 00000293 RAX: ffffffff81d6c13c RBX: 0000000000000000 RCX: ffff88802a49d940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90005f4f7e0 R08: ffffffff901d5177 R09: 1ffffffff203aa2e R10: dffffc0000000000 R11: fffffbfff203aa2f R12: dffffc0000000000 R13: 0000000000000200 R14: ffffffff81d69aa6 R15: 1ffff92000be9ee4 read_seqbegin include/linux/seqlock.h:897 [inline] read_seqbegin_or_lock include/linux/seqlock.h:1191 [inline] prepend_path+0xc6/0xbb0 fs/d_path.c:167 d_absolute_path+0x9e/0x140 fs/d_path.c:235 tomoyo_get_absolute_path security/tomoyo/realpath.c:101 [inline] tomoyo_realpath_from_path+0x331/0x610 security/tomoyo/realpath.c:276 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path2_perm+0x2a0/0x840 security/tomoyo/file.c:923 tomoyo_path_rename+0xfd/0x150 security/tomoyo/tomoyo.c:278 security_path_rename+0x1dc/0x280 security/security.c:1206 do_renameat2+0x69b/0xf60 fs/namei.c:4980 __do_sys_rename fs/namei.c:5039 [inline] __se_sys_rename fs/namei.c:5037 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:5037 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: 0033:0x7fce3d14dcc7 RSP: 002b:00007ffe1c462e18 EFLAGS: 00000202 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 000055601ecee280 RCX: 00007fce3d14dcc7 RDX: 000055601ece6010 RSI: 00007ffe1c462e30 RDI: 00007ffe1c463230 RBP: 000055601ed00320 R08: 00000000000001e0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffe1c462e30 R13: 00007ffe1c463230 R14: 0000000000000000 R15: 0000555fef95c9dd rcu: rcu_preempt kthread timer wakeup didn't happen for 10563 jiffies! g62385 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=32577 rcu: rcu_preempt kthread starved for 10569 jiffies! g62385 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:27760 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 14 Comm: ksoftirqd/0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:stack_trace_consume_entry+0xef/0x270 kernel/stacktrace.c:93 Code: 8b 74 24 08 48 8b 1f 45 8d 79 01 0f b6 44 15 00 84 c0 0f 85 35 01 00 00 45 89 38 4e 8d 3c cb 4c 89 f8 48 c1 e8 03 80 3c 10 00 <74> 1a 4c 89 ff 48 89 f3 49 89 d4 4c 89 c5 e8 6e a5 56 00 49 89 e8 RSP: 0018:ffffc90000d373f8 EFLAGS: 00000246 RAX: 1ffff920001a6eb4 RBX: ffffc90000d37580 RCX: 0000000000000101 RDX: dffffc0000000000 RSI: ffffffff88a36606 RDI: ffffc90000d37500 RBP: 1ffff920001a6ea2 R08: ffffc90000d37510 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff520001a6e95 R12: 0000000000000000 R13: 1ffff920001a6ea1 R14: ffffc90000d37508 R15: ffffc90000d375a0 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffa170ddd58 CR3: 0000000056f80000 CR4: 00000000003506f0 DR0: 0000000000000008 DR1: 0000000000000002 DR2: 0000000000000404 DR3: ffffffffefffff14 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x100/0x140 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] kmem_cache_alloc_node+0x12d/0x2d0 mm/slub.c:3261 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1162 [inline] ndisc_alloc_skb+0xa6/0x420 net/ipv6/ndisc.c:422 ndisc_send_rs+0x291/0x730 net/ipv6/ndisc.c:691 addrconf_rs_timer+0x2d1/0x630 net/ipv6/addrconf.c:3956 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648 expire_timers kernel/time/timer.c:1699 [inline] __run_timers+0x53e/0x800 kernel/time/timer.c:1970 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983 handle_softirqs+0x339/0x830 kernel/softirq.c:576 run_ksoftirqd+0xa4/0x100 kernel/softirq.c:943 smpboot_thread_fn+0x4f6/0x970 kernel/smpboot.c:164 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287