rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6365/1:b..l P5177/1:b..l
rcu: (detected by 0, t=10510 jiffies, g=15129, q=2368 ncpus=2)
task:udevd state:R running task stack:25512 pid:5177 tgid:5177 ppid:1 task_flags:0x400140 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7095
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline]
_raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:389 [inline]
wp_page_copy mm/memory.c:3881 [inline]
do_wp_page+0x15b3/0x4e90 mm/memory.c:4241
handle_pte_fault mm/memory.c:6333 [inline]
__handle_mm_fault+0x1ace/0x2b60 mm/memory.c:6455
handle_mm_fault+0x36d/0xa20 mm/memory.c:6624
do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1334
handle_page_fault arch/x86/mm/fault.c:1474 [inline]
exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7fe0410b8b3a
RSP: 002b:00007ffcb108e720 EFLAGS: 00010246
RAX: 00007fe0411f1b20 RBX: 0000000000000020 RCX: 0000000000000100
RDX: 0000557b007ecf40 RSI: 00007fe0411f1c30 RDI: 0000557b007ecf20
RBP: 00007fe0411f1ac0 R08: 00007fe0411f1ac0 R09: 0000000000000020
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000006
R13: 0000557b007ecf20 R14: 0000000000000120 R15: 00007fe0411f1b20
task:syz-executor state:R running task stack:24136 pid:6365 tgid:6365 ppid:6363 task_flags:0x400140 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7238
irqentry_exit+0x17b/0x670 kernel/entry/common.c:239
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:81 [inline]
RIP: 0010:__orc_find+0x70/0xf0 arch/x86/kernel/unwind_orc.c:103
Code: ec 72 4e 4c 89 e2 48 29 ea 48 89 d6 48 c1 ea 3f 48 c1 fe 02 48 01 f2 48 d1 fa 48 8d 5c 95 00 48 89 da 48 c1 ea 03 0f b6 34 0a <48> 89 da 83 e2 07 83 c2 03 40 38 f2 7c 05 40 84 f6 75 4b 48 63 13
RSP: 0018:ffffc90002f46c70 EFLAGS: 00000a03
RAX: ffffffff91a38b74 RBX: ffffffff910e83cc RCX: dffffc0000000000
RDX: 1ffffffff221d079 RSI: 0000000000000000 RDI: ffffffff910e83cc
RBP: ffffffff910e83cc R08: ffffffff91a38b7a R09: 0000000000000007
R10: 0000000000000200 R11: 000000000002fda9 R12: ffffffff910e83cc
R13: ffffffff83fda9ed R14: ffffffff910e83cc R15: ffffffff910e83cc
orc_find arch/x86/kernel/unwind_orc.c:238 [inline]
unwind_next_frame+0x2ec/0x1ea0 arch/x86/kernel/unwind_orc.c:510
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x162/0x1e0 mm/page_owner.c:165
__reset_page_owner+0x84/0x190 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1433 [inline]
__free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978
selinux_genfs_get_sid security/selinux/hooks.c:1364 [inline]
inode_doinit_with_dentry+0x99d/0x1320 security/selinux/hooks.c:1562
selinux_d_instantiate+0x26/0x40 security/selinux/hooks.c:6550
security_d_instantiate+0x14c/0x1b0 security/security.c:3602
d_make_persistent+0x6a/0x190 fs/dcache.c:2800
__debugfs_create_file+0x25e/0x4f0 fs/debugfs/inode.c:450
debugfs_create_file_short+0x41/0x60 fs/debugfs/inode.c:471
add_sta_files net/mac80211/debugfs_netdev.c:844 [inline]
add_files net/mac80211/debugfs_netdev.c:957 [inline]
ieee80211_debugfs_add_netdev net/mac80211/debugfs_netdev.c:1010 [inline]
ieee80211_debugfs_recreate_netdev+0x850/0x1790 net/mac80211/debugfs_netdev.c:1034
ieee80211_if_add+0xa30/0x1860 net/mac80211/iface.c:2323
ieee80211_register_hw+0x38a4/0x4140 net/mac80211/main.c:1617
mac80211_hwsim_new_radio+0x2847/0x57d0 drivers/net/wireless/virtual/mac80211_hwsim.c:5809
hwsim_new_radio_nl+0xc1f/0x1340 drivers/net/wireless/virtual/mac80211_hwsim.c:6503
genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
__sys_sendto+0x468/0x4b0 net/socket.c:2206
__do_sys_sendto net/socket.c:2213 [inline]
__se_sys_sendto net/socket.c:2209 [inline]
__x64_sys_sendto+0xe0/0x1c0 net/socket.c:2209
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fafc8d5b7ce
RSP: 002b:00007ffe553dc5c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000555578248500 RCX: 00007fafc8d5b7ce
RDX: 0000000000000024 RSI: 00007fafc9b34670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffe553dc644 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 00007fafc9b34670 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10457 jiffies! g15129 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27976 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 338 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x583/0x1500 kernel/smp.c:877
Code: 00 fc ff df 48 8b 54 24 10 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 74 68 0c 00 f3 90 41 0f b6 45 00 <41> 38 c4 7c 08 84 c0 0f 85 91 0d 00 00 8b 45 08 31 ff 83 e0 01 41
RSP: 0018:ffffc90002f76870 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81fc8f12
RDX: ffff888023b80000 RSI: ffffffff81fc8eec RDI: ffff888023b80000
RBP: ffff8880b8540da0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170a81b5 R14: 0000000000000001 R15: ffff8880b843c440
FS: 0000000000000000(0000) GS:ffff888124338000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe58b02a368 CR3: 0000000035045000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:57 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
flush_tlb_mm_range+0x45f/0x1710 arch/x86/mm/tlb.c:1472
flush_tlb_page arch/x86/include/asm/tlbflush.h:323 [inline]
ptep_clear_flush+0x148/0x170 mm/pgtable-generic.c:103
page_vma_mkclean_one.constprop.0+0x3a2/0x7b0 mm/rmap.c:1132
page_mkclean_one+0x1cd/0x2b0 mm/rmap.c:1180
__rmap_walk_file+0x383/0x680 mm/rmap.c:3056
rmap_walk_file+0x1d8/0x2a0 mm/rmap.c:3089
rmap_walk mm/rmap.c:3100 [inline]
folio_mkclean+0x2af/0x4e0 mm/rmap.c:1212
folio_clear_dirty_for_io+0x1ba/0x820 mm/page-writeback.c:2909
mpage_submit_folio+0x84/0x330 fs/ext4/inode.c:2071
mpage_map_and_submit_buffers+0x5f2/0xb50 fs/ext4/inode.c:2333
mpage_map_and_submit_extent fs/ext4/inode.c:2523 [inline]
ext4_do_writepages+0x23fa/0x3f50 fs/ext4/inode.c:2935
ext4_writepages+0x347/0x790 fs/ext4/inode.c:3029
do_writepages+0x278/0x600 mm/page-writeback.c:2575
__writeback_single_inode+0x164/0x13c0 fs/fs-writeback.c:1762
writeback_sb_inodes+0x766/0x1c70 fs/fs-writeback.c:2054
__writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2130
wb_writeback+0x755/0xbe0 fs/fs-writeback.c:2241
wb_check_old_data_flush fs/fs-writeback.c:2345 [inline]
wb_do_writeback fs/fs-writeback.c:2398 [inline]
wb_workfn+0x8c6/0xc00 fs/fs-writeback.c:2426
process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
process_scheduled_works kernel/workqueue.c:3359 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
sched: DL replenish lagged too much