rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1):
P5851/1:b.el
P5852/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=13293, q=632 ncpus=2)
task:syz-executor state:R
running task stack:21832 pid:5852 tgid:5852 ppid:5828 task_flags:0x400140 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6965
preempt_schedule+0xae/0xc0 kernel/sched/core.c:6989
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
copy_pte_range mm/memory.c:1206 [inline]
copy_pmd_range+0x6727/0x7000 mm/memory.c:1267
copy_pud_range mm/memory.c:1304 [inline]
copy_p4d_range mm/memory.c:1328 [inline]
copy_page_range+0xc46/0x1270 mm/memory.c:1416
dup_mmap+0xf57/0x1ac0 mm/mmap.c:1838
dup_mm kernel/fork.c:1477 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1529
copy_process+0x1706/0x3c00 kernel/fork.c:2169
kernel_clone+0x21e/0x870 kernel/fork.c:2599
__do_sys_clone kernel/fork.c:2742 [inline]
__se_sys_clone kernel/fork.c:2726 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2726
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f912f385193
RSP: 002b:00007f912f6dfca8 EFLAGS: 00000246
ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f912f385193
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 000055558865e7d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000001cbd7 R15: 00007f912f6dfe40
task:udevd state:R
running task stack:26352 pid:5851 tgid:5851 ppid:5204 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108
irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:58 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:393 [inline]
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline]
RIP: 0010:unwind_next_frame+0xb37/0x2390 arch/x86/kernel/unwind_orc.c:585
Code: df e8 3d 25 b1 00 48 89 9c 24 88 00 00 00 49 8d 5c 24 f8 4d 8b 66 10 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 20 0f b6 04 01 <84> c0 0f 85 85 13 00 00 41 83 3e 00 0f 95 c0 49 39 df 0f 96 c1 20
RSP: 0018:ffffc90004dbf858 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc90004dbfee8 RCX: 1ffff920009b7f25
RDX: ffffffff903eb434 RSI: 0000000000000002 RDI: ffffffff8be282e0
RBP: 1ffff920009b7f26 R08: 0000000000000008 R09: ffffffff81729de5
R10: ffffc90004dbf978 R11: ffffffff81acf670 R12: ffffc90004dc0000
R13: 1ffff920009b7f27 R14: ffffc90004dbf928 R15: ffffc90004db8000
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2381 [inline]
slab_free mm/slub.c:4643 [inline]
kfree+0x18e/0x440 mm/slub.c:4842
seq_release+0x54/0x70 fs/seq_file.c:355
kernfs_fop_release+0x133/0x190 fs/kernfs/file.c:766
__fput+0x449/0xa70 fs/file_table.c:465
fput_close_sync+0x119/0x200 fs/file_table.c:570
__do_sys_close fs/open.c:1589 [inline]
__se_sys_close fs/open.c:1574 [inline]
__x64_sys_close+0x7f/0x110 fs/open.c:1574
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1818f15a67
RSP: 002b:00007ffe9715b748 EFLAGS: 00000297
ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 000055cae1999770 RCX: 00007f1818f15a67
RDX: 00007f1818fefea0 RSI: 000055cae19db7d0 RDI: 0000000000000008
RBP: 00007f1818fefff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000000
R13: 3d45505954564544 R14: 3d5845444e494649 R15: 3d454d414e564544
rcu: rcu_preempt kthread starved for 10150 jiffies! g13293 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:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.15.0-syzkaller-12426-ge271ed52b344 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc cc cc cc 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 a3 75 22 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c2
RAX: 6132121cbc57f900 RBX: ffffffff81976058 RCX: 6132121cbc57f900
RDX: 0000000000000001 RSI: ffffffff8d97cc47 RDI: ffffffff8be28340
RBP: ffffc90000197f20 R08: ffff8880b8732f5b R09: 1ffff110170e65eb
R10: dffffc0000000000 R11: ffffed10170e65ec R12: ffffffff8fa101f0
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003a57b40
FS: 0000000000000000(0000) GS:ffff888125d55000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055cae19d7c88 CR3: 0000000032240000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:743
default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
cpuidle_idle_call kernel/sched/idle.c:185 [inline]
do_idle+0x1e8/0x510 kernel/sched/idle.c:325
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x147