rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5219/1:b..l P6992/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=25621, q=1524065 ncpus=2)
task:syz-executor state:R running task stack:23832 pid:6992 tgid:6992 ppid:6975 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
irqentry_exit+0x36/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:unwind_next_frame+0xfe7/0x20a0 arch/x86/kernel/unwind_orc.c:664
Code: 85 80 0c 00 00 49 89 6d 40 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 56 10 00 00 <41> 39 5d 00 0f 84 10 06 00 00 bd 01 00 00 00 e9 de f3 ff ff 48 b8
RSP: 0018:ffffc90003097870 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff91d32312
RDX: 1ffff92000612f1c RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffffc90003097928 R08: ffffffff91d32316 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000086437 R12: ffffc90003097930
R13: ffffc900030978e0 R14: ffffc90003097f28 R15: ffffc90003097914
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x160/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x84/0x1a0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
__free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895
discard_slab mm/slub.c:2758 [inline]
__put_partials+0x165/0x1c0 mm/slub.c:3223
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:340
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4191 [inline]
slab_alloc_node mm/slub.c:4240 [inline]
kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4247
lsm_file_alloc security/security.c:733 [inline]
security_file_alloc+0x34/0x2b0 security/security.c:2888
init_file+0x93/0x4c0 fs/file_table.c:159
alloc_empty_file+0x73/0x1e0 fs/file_table.c:241
alloc_file fs/file_table.c:354 [inline]
alloc_file_pseudo+0x13a/0x230 fs/file_table.c:383
sock_alloc_file+0x50/0x210 net/socket.c:470
sock_map_fd net/socket.c:500 [inline]
__sys_socket+0x1c0/0x260 net/socket.c:1740
__do_sys_socket net/socket.c:1745 [inline]
__se_sys_socket net/socket.c:1743 [inline]
__x64_sys_socket+0x72/0xb0 net/socket.c:1743
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f30b1990de7
RSP: 002b:00007ffce4458e48 EFLAGS: 00000206 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f30b1990de7
RDX: 0000000000000006 RSI: 0000000000000001 RDI: 000000000000000a
RBP: 00007ffce445957c R08: 0000000000000000 R09: 00007ffce4459287
R10: 0000000000000000 R11: 0000000000000206 R12: 00007f30b1bb2ca0
R13: 00000000000927c0 R14: 0000000000043a0e R15: 00007f30b1bb4e60
task:udevd state:R running task stack:26200 pid:5219 tgid:5219 ppid:1 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
irqentry_exit+0x36/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872
Code: 19 3f 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 c2 9f 13 0f 0f 82 74 02 00 00 8b 35 7a d1 13 0f 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 19 19 3f 12 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc90003637478 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e5c16a0 RCX: 00000000fdedef1f
RDX: 0000000000000000 RSI: ffffffff8de2da30 RDI: ffffffff8c163380
RBP: 0000000000000002 R08: 8bfc3957ff8205e7 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x160/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x84/0x1a0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
__free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895
discard_slab mm/slub.c:2758 [inline]
__put_partials+0x165/0x1c0 mm/slub.c:3223
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:340
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4191 [inline]
slab_alloc_node mm/slub.c:4240 [inline]
__kmalloc_cache_noprof+0x1f1/0x3e0 mm/slub.c:4402
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
kernfs_get_open_node fs/kernfs/file.c:543 [inline]
kernfs_fop_open+0xa3a/0xda0 fs/kernfs/file.c:718
do_dentry_open+0x97f/0x1530 fs/open.c:965
vfs_open+0x82/0x3f0 fs/open.c:1095
do_open fs/namei.c:3887 [inline]
path_openat+0x1de4/0x2cb0 fs/namei.c:4046
do_filp_open+0x20b/0x470 fs/namei.c:4073
do_sys_openat2+0x11b/0x1d0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x174/0x210 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f319aea7407
RSP: 002b:00007ffc15434690 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f319b615880 RCX: 00007f319aea7407
RDX: 0000000000080000 RSI: 00007ffc15434810 RDI: ffffffffffffff9c
RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000056396296b7f5
R13: 000056396296b7f5 R14: 0000000000000001 R15: 00007ffc15438e60
rcu: rcu_preempt kthread starved for 1631 jiffies! g25621 f0x2 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:27672 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x56a/0x730 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 syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 3d 61 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 d3 16 15 00 fb f4 cc 09 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df8 EFLAGS: 000002c2
RAX: 0000000001eac591 RBX: 0000000000000001 RCX: ffffffff8b94fb49
RDX: 0000000000000000 RSI: ffffffff8de52fc1 RDI: ffffffff8c163380
RBP: ffffed1003c5d488 R08: 0000000000000001 R09: ffffed10170a6655
R10: ffff8880b85332ab R11: 0000000000000000 R12: 0000000000000001
R13: ffff88801e2ea440 R14: ffffffff90ab7690 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881247b1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556b7d35c8 CR3: 000000004e7e5000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:757
default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x391/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x148