rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 1, t=10506 jiffies, g=52173, q=191 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10506 (4294992505-4294981999), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10506 jiffies! g52173 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:27592 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7326
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 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: 1 UID: 0 PID: 10197 Comm: syz.4.1024 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x593/0x16c0 kernel/smp.c:892
Code: 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 a9 95 0c 00 f3 90 41 0f b6 45 00 41 38 c4 7c 08 <84> c0 0f 85 2c 0f 00 00 8b 45 08 31 ff 83 e0 01 41 89 c6 89 c6 e8
RSP: 0018:ffffc90004cbf650 EFLAGS: 00000206
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81fd3abd
RDX: ffff888034fbca80 RSI: ffffffff81fd3a97 RDI: ffff888034fbca80
RBP: ffff8880b8443680 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170886d1 R14: 0000000000000001 R15: ffff8880b853c880
FS: 0000000000000000(0000) GS:ffff888123eec000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7813d27080 CR3: 000000000e992000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057
__flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
flush_tlb_mm_range+0x45f/0x16f0 arch/x86/mm/tlb.c:1451
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:509 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:499 [inline]
tlb_flush_mmu mm/mmu_gather.c:423 [inline]
tlb_finish_mmu+0x3fe/0x810 mm/mmu_gather.c:549
exit_mmap+0x454/0xa00 mm/mmap.c:1313
__mmput+0x12a/0x410 kernel/fork.c:1187
mmput+0x67/0x80 kernel/fork.c:1210
exit_mm kernel/exit.c:610 [inline]
do_exit+0x8b1/0x2ae0 kernel/exit.c:992
do_group_exit+0xd5/0x2a0 kernel/exit.c:1147
get_signal+0x1ec7/0x21e0 kernel/signal.c:3038
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x139/0x6f0 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f859459de59
Code: Unable to access opcode bytes at 0x7f859459de2f.
RSP: 002b:00007f85927d5028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: 0000000000000034 RBX: 00007f8594826180 RCX: 00007f859459de59
RDX: 0000000000000000 RSI: 0000200000000140 RDI: 0000000000000006
RBP: 00007f8594633e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8594826218 R14: 00007f8594826180 R15: 00007fff1deb83b8
watchdog: BUG: soft lockup - CPU#1 stuck for 246s! [syz.4.1024:10197]
Modules linked in:
irq event stamp: 757182
hardirqs last enabled at (757181): [] irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:507 [inline]
hardirqs last enabled at (757181): [] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:542 [inline]
hardirqs last enabled at (757181): [] irqentry_exit+0x24d/0xa00 kernel/entry/common.c:167
hardirqs last disabled at (757182): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1062
softirqs last enabled at (757178): [] __do_softirq kernel/softirq.c:656 [inline]
softirqs last enabled at (757178): [] invoke_softirq kernel/softirq.c:496 [inline]
softirqs last enabled at (757178): [] __irq_exit_rcu+0x162/0x210 kernel/softirq.c:735
softirqs last disabled at (757137): [] __do_softirq kernel/softirq.c:656 [inline]
softirqs last disabled at (757137): [] invoke_softirq kernel/softirq.c:496 [inline]
softirqs last disabled at (757137): [] __irq_exit_rcu+0x162/0x210 kernel/softirq.c:735
CPU: 1 UID: 0 PID: 10197 Comm: syz.4.1024 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x589/0x16c0 kernel/smp.c:892
Code: b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 a9 95 0c 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 2c 0f 00 00 8b 45 08 31
RSP: 0018:ffffc90004cbf650 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81fd3abd
RDX: ffff888034fbca80 RSI: ffffffff81fd3a97 RDI: ffff888034fbca80
RBP: ffff8880b8443680 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170886d1 R14: 0000000000000001 R15: ffff8880b853c880
FS: 0000000000000000(0000) GS:ffff888123eec000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7813d27080 CR3: 000000000e992000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057
__flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
flush_tlb_mm_range+0x45f/0x16f0 arch/x86/mm/tlb.c:1451
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:509 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:499 [inline]
tlb_flush_mmu mm/mmu_gather.c:423 [inline]
tlb_finish_mmu+0x3fe/0x810 mm/mmu_gather.c:549
exit_mmap+0x454/0xa00 mm/mmap.c:1313
__mmput+0x12a/0x410 kernel/fork.c:1187
mmput+0x67/0x80 kernel/fork.c:1210
exit_mm kernel/exit.c:610 [inline]
do_exit+0x8b1/0x2ae0 kernel/exit.c:992
do_group_exit+0xd5/0x2a0 kernel/exit.c:1147
get_signal+0x1ec7/0x21e0 kernel/signal.c:3038
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x139/0x6f0 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f859459de59
Code: Unable to access opcode bytes at 0x7f859459de2f.
RSP: 002b:00007f85927d5028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: 0000000000000034 RBX: 00007f8594826180 RCX: 00007f859459de59
RDX: 0000000000000000 RSI: 0000200000000140 RDI: 0000000000000006
RBP: 00007f8594633e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8594826218 R14: 00007f8594826180 R15: 00007fff1deb83b8
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9699 Comm: kworker/u8:24 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_unbound linkwatch_event
RIP: 0010:write_comp_data+0x7/0x90 kernel/kcov.c:240
Code: 7c 24 08 e8 ab 7e 70 00 e9 6d fd ff ff 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 8b 05 39 77 59 12 <49> 89 f8 49 89 f1 49 89 d2 65 48 8b 3d 10 77 59 12 a9 00 01 ff 00
RSP: 0018:ffffc90000007de0 EFLAGS: 00000046
RAX: 0000000000010203 RBX: ffff88802c6ed300 RCX: ffffffff89c6d087
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88802c6ed300
R13: ffffffff89c6cf40 R14: ffff8880b8428640 R15: ffff8880b8428690
FS: 0000000000000000(0000) GS:ffff888123dec000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7812deb540 CR3: 000000007e188000 CR4: 00000000003526f0
Call Trace:
advance_sched+0x147/0xd20 net/sched/sch_taprio.c:933
__run_hrtimer kernel/time/hrtimer.c:2032 [inline]
__hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096
hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:console_flush_one_record+0xac3/0xe50 kernel/printk/printk.c:3270
Code: 00 e8 11 26 2a 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 1f d2 21 00 48 85 ed 0f 85 d7 01 00 00 e8 71 d7 21 00 fb 4c 89 e8 <48> c1 e8 03 42 80 3c 38 00 0f 85 64 03 00 00 48 8b 0c 24 48 8b 6b
RSP: 0018:ffffc900034af468 EFLAGS: 00000293
RAX: ffffffff8f9a9cd8 RBX: ffffffff8f9a9c80 RCX: ffffffff81e7f8c1
RDX: ffff88807b014a80 RSI: ffffffff81e7f8cf RDI: ffff88807b014a80
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000001aa8
R13: ffffffff8f9a9cd8 R14: ffffc900034af4e8 R15: dffffc0000000000
console_flush_all kernel/printk/printk.c:3343 [inline]
__console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
console_unlock+0x103/0x260 kernel/printk/printk.c:3413
vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2479
_printk+0xcf/0x110 kernel/printk/printk.c:2504
br_set_state+0x386/0x620 net/bridge/br_stp.c:57
br_init_port+0xc9/0x210 net/bridge/br_stp_if.c:39
br_stp_enable_port+0x15/0x50 net/bridge/br_stp_if.c:93
br_port_carrier_check+0x26f/0x4d0 net/bridge/br_if.c:90
br_device_event+0x821/0xa00 net/bridge/br.c:101
notifier_call_chain+0x99/0x3f0 kernel/notifier.c:85
call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2250
netif_state_change+0x165/0x380 net/core/dev.c:1603
linkwatch_do_dev net/core/link_watch.c:186 [inline]
linkwatch_do_dev+0xe0/0x120 net/core/link_watch.c:166
__linkwatch_run_queue+0x3a9/0x900 net/core/link_watch.c:240
linkwatch_event+0x8f/0xc0 net/core/link_watch.c:314
process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
process_scheduled_works kernel/workqueue.c:3405 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245