rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9657/1:b..l P5810/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=31137, q=341 ncpus=2)
task:udevd state:R running task stack:24952 pid:5810 tgid:5810 ppid:5183 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:debug_lockdep_rcu_enabled+0x26/0x40 kernel/rcu/update.c:320
Code: 90 90 90 90 f3 0f 1e fa 8b 05 56 82 10 05 85 c0 74 20 8b 05 00 b2 10 05 85 c0 74 16 65 48 8b 05 98 78 3a 08 8b 80 2c 0b 00 00 <85> c0 0f 94 c0 0f b6 c0 e9 0d 2c 03 00 66 2e 0f 1f 84 00 00 00 00
RSP: 0018:ffffc9000237f938 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8243ad89
RDX: ffff88807a3424c0 RSI: ffffffff8243ad96 RDI: 0000000000000001
RBP: ffffc900005168d8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: ffff88807a342ff0 R12: 0000000062d1b2c0
R13: ffff888079b93938 R14: ffff888079af1028 R15: ffffc9000237fb30
rcu_read_lock_held_common kernel/rcu/update.c:105 [inline]
rcu_read_lock_held+0x9/0x50 kernel/rcu/update.c:349
hlist_bl_first_rcu include/linux/rculist_bl.h:24 [inline]
__d_lookup+0x2cb/0x4a0 fs/dcache.c:2437
lookup_fast+0x17c/0x610 fs/namei.c:1824
walk_component fs/namei.c:2225 [inline]
link_path_walk+0x7d6/0x1c70 fs/namei.c:2597
path_lookupat+0x74/0xc40 fs/namei.c:2753
filename_lookup+0x224/0x5f0 fs/namei.c:2783
vfs_statx+0x101/0x3f0 fs/stat.c:353
vfs_fstatat+0x7b/0xf0 fs/stat.c:375
__do_sys_newfstatat+0x97/0x120 fs/stat.c:542
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc7e6f11b0a
RSP: 002b:00007ffc23c15928 EFLAGS: 00000202 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 0000564c521c9735 RCX: 00007fc7e6f11b0a
RDX: 00007ffc23c15930 RSI: 00007ffc23c159c0 RDI: 00000000ffffff9c
RBP: 0000564c601e0750 R08: 0000564c521c9735 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000202 R12: 0000564c601e0840
R13: 00007ffc23c159c0 R14: 00007ffc23c16ea0 R15: 0000564c521cfbcc
task:modprobe state:R running task stack:25032 pid:9657 tgid:9657 ppid:12 task_flags:0x40000c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:stack_access_ok+0x166/0x200 arch/x86/kernel/unwind_orc.c:414
Code: 0f 85 95 00 00 00 48 8b 43 10 49 39 ee 77 29 48 39 e8 76 24 4c 01 e5 48 39 e8 0f 93 c0 49 39 ee 0f 92 c2 21 d0 48 83 c4 08 5b <5d> 41 5c 41 5d 41 5e 41 5f e9 8c ae 0e 0a 48 83 c4 08 31 c0 5b 5d
RSP: 0018:ffffc900043ff528 EFLAGS: 00000292
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffc90004400000
RDX: ffffc900043ff501 RSI: ffffc900043ff5e8 RDI: ffffc900043ff618
RBP: ffffc900043ff5e8 R08: 0000000000000001 R09: 000000002d64dbdc
R10: 0000000000000002 R11: 0000000000006cdb R12: 0000000000000008
R13: ffffc900043ff628 R14: ffffc900043ff620 R15: ffffc900043f8000
deref_stack_reg arch/x86/kernel/unwind_orc.c:419 [inline]
unwind_next_frame+0x1509/0x20b0 arch/x86/kernel/unwind_orc.c:663
__unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:773
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
kmalloc_noprof include/linux/slab.h:957 [inline]
slab_free_hook mm/slub.c:2492 [inline]
slab_free mm/slub.c:6670 [inline]
kmem_cache_free+0x147/0x770 mm/slub.c:6781
anon_vma_free mm/rmap.c:136 [inline]
__put_anon_vma+0x114/0x3a0 mm/rmap.c:2780
put_anon_vma include/linux/rmap.h:117 [inline]
unlink_anon_vmas+0x58a/0x820 mm/rmap.c:443
free_pgtables+0x212/0xc10 mm/memory.c:414
exit_mmap+0x3f1/0xb60 mm/mmap.c:1288
__mmput+0x12a/0x410 kernel/fork.c:1173
mmput+0x62/0x70 kernel/fork.c:1196
exit_mm kernel/exit.c:581 [inline]
do_exit+0x7d7/0x2bd0 kernel/exit.c:959
do_group_exit+0xd3/0x2a0 kernel/exit.c:1112
__do_sys_exit_group kernel/exit.c:1123 [inline]
__se_sys_exit_group kernel/exit.c:1121 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1121
x64_sys_call+0x151c/0x1740 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbb3ca456c5
RSP: 002b:00007fffdb68f9b8 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fbb3cb46fe8 RCX: 00007fbb3ca456c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000001
RBP: 0000000000000001 R08: 00007fffdb68f948 R09: 0000000000000000
R10: 00007fffdb68f7e0 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fbb3cb45680 R15: 00007fbb3cb47000
rcu: rcu_preempt kthread starved for 10567 jiffies! g31137 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:28064 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 96 5f 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 13 19 12 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197de8 EFLAGS: 000002c6
RAX: 0000000000f1a635 RBX: 0000000000000001 RCX: ffffffff8b7846d9
RDX: 0000000000000000 RSI: ffffffff8dace97a RDI: ffffffff8bf2b400
RBP: ffffed1003bdd498 R08: 0000000000000001 R09: ffffed10170a673d
R10: ffff8880b85339eb R11: ffff88801deeaff0 R12: 0000000000000001
R13: ffff88801deea4c0 R14: ffffffff9088b8d0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881249f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f924224 CR3: 00000000751f3000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x38d/0x510 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x148