rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9512/1:b..l P5193/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=35373, q=194 ncpus=2)
task:udevd state:R running task stack:22264 pid:5193 tgid:5193 ppid:1 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7047
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]
__d_lookup+0x624/0x780 fs/dcache.c:2453
lookup_fast+0x84/0x5b0 fs/namei.c:1824
walk_component fs/namei.c:2225 [inline]
link_path_walk+0x720/0x18d0 fs/namei.c:2597
path_lookupat+0xe4/0x8c0 fs/namei.c:2753
filename_lookup+0x212/0x570 fs/namei.c:2783
vfs_statx+0xf8/0x550 fs/stat.c:353
vfs_fstatat+0x118/0x170 fs/stat.c:375
__do_sys_newfstatat fs/stat.c:542 [inline]
__se_sys_newfstatat fs/stat.c:536 [inline]
__x64_sys_newfstatat+0x116/0x190 fs/stat.c:536
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1c80911b0a
RSP: 002b:00007ffe257e87d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 00007ffe257e8c70 RCX: 00007f1c80911b0a
RDX: 00007ffe257e87e0 RSI: 00007ffe257e8c70 RDI: 00000000ffffff9c
RBP: 00005645d50cc910 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe257e8870
R13: 0000000000000100 R14: 00005645a619bbe0 R15: 00007ffe257e92f0
task:syz.3.844 state:R running task stack:25304 pid:9512 tgid:9510 ppid:5844 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190
irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_is_held_type+0x107/0x150 kernel/locking/lockdep.c:5945
Code: 18 00 00 b8 ff ff ff ff 65 0f c1 05 73 61 26 07 83 f8 01 75 25 9c 58 a9 00 02 00 00 75 39 41 f7 c4 00 02 00 00 74 01 fb 89 d8 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 a5 0c b6 f5 cc 90 0f 0b 90 48 c7
RSP: 0018:ffffc9000b5577d0 EFLAGS: 00000206
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 00000000ac4ac242 RSI: ffffffff8d9779a6 RDI: ffffffff8bc08760
RBP: 00000000ffffffff R08: ffffffff822f2508 R09: ffffffff8df41aa0
R10: dffffc0000000000 R11: fffff940003a4279 R12: 0000000000000246
R13: ffff888024f08000 R14: ffffffff8df7b9a8 R15: 0000000000000003
lock_is_held include/linux/lockdep.h:249 [inline]
task_css include/linux/cgroup.h:460 [inline]
mem_cgroup_from_task+0x62/0x120 mm/memcontrol.c:885
get_mem_cgroup_from_mm+0xd6/0x2a0 mm/memcontrol.c:938
__mem_cgroup_charge+0x15/0x80 mm/memcontrol.c:4744
mem_cgroup_charge include/linux/memcontrol.h:663 [inline]
shmem_alloc_and_add_folio+0x790/0xf40 mm/shmem.c:1942
shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2556
shmem_get_folio mm/shmem.c:2662 [inline]
shmem_write_begin+0x16c/0x330 mm/shmem.c:3315
generic_perform_write+0x2c5/0x900 mm/filemap.c:4314
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3490
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5c9/0xb30 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1d8438e1ff
RSP: 002b:00007f1d8515adf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000200000 RCX: 00007f1d8438e1ff
RDX: 0000000000200000 RSI: 00007f1d7a000000 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000001f2ad
R10: 0000000000003ffe R11: 0000000000000293 R12: 0000000000000005
R13: 00007f1d8515aef0 R14: 00007f1d8515aeb0 R15: 00007f1d7a000000
rcu: rcu_preempt kthread starved for 10570 jiffies! g35373 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:27712 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 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 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__rcu_read_lock+0x32/0x60 kernel/rcu/tree_plugin.h:416
Code: 1c 25 08 50 80 92 48 81 c3 84 04 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 18 ff 03 8b 03 <3d> 00 00 00 40 7d 07 5b e9 2c 91 68 ff cc 90 0f 0b 90 eb f3 89 d9
RSP: 0018:ffffc90000a08568 EFLAGS: 00000206
RAX: 0000000000000003 RBX: ffff88801c2fe004 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: ffffffff816597e7 RDI: ffffc90000a08648
RBP: dffffc0000000000 R08: ffffc90000a08710 R09: 0000000000000018
R10: dffffc0000000000 R11: ffffffff81acf510 R12: 1ffff920001410c9
R13: ffffc90000a08680 R14: ffffc90000a08648 R15: ffffc90000197f48
FS: 0000000000000000(0000) GS:ffff888125f1b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1c8104e000 CR3: 000000005026f000 CR4: 0000000000350ef0
Call Trace:
rcu_read_lock include/linux/rcupdate.h:865 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0x9e/0x23d0 arch/x86/kernel/unwind_orc.c:495
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:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_node_noprof+0x43c/0x720 mm/slub.c:5315
__alloc_skb+0x1dc/0x3a0 net/core/skbuff.c:679
__netdev_alloc_skb+0xc1/0x850 net/core/skbuff.c:754
netdev_alloc_skb include/linux/skbuff.h:3484 [inline]
dev_alloc_skb include/linux/skbuff.h:3497 [inline]
__ieee80211_beacon_get+0xc06/0x1880 net/mac80211/tx.c:5656
ieee80211_beacon_get_tim+0xb4/0x2b0 net/mac80211/tx.c:5778
ieee80211_beacon_get include/net/mac80211.h:5669 [inline]
mac80211_hwsim_beacon_tx+0x3c5/0x870 drivers/net/wireless/virtual/mac80211_hwsim.c:2361
__iterate_interfaces+0x2ab/0x590 net/mac80211/util.c:761
ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:797
mac80211_hwsim_beacon+0xbb/0x180 drivers/net/wireless/virtual/mac80211_hwsim.c:2395
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x51c/0xc30 kernel/time/hrtimer.c:1841
hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1858
handle_softirqs+0x22b/0x7c0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x60/0x150 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 1e 14 b6 f5 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 53 21 0e 00 f3 0f 1e fa fb f4 f3 13 b6 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197e20 EFLAGS: 000002c6
RAX: 000000000044b851 RBX: ffffffff8197149e RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8d793aa5 RDI: ffffffff8bc08760
RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db
R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8f823070
R13: 1ffff1100385fb70 R14: 0000000000000001 R15: 0000000000000001
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1be/0x4d0 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147