rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5830/1:b..l P90/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=7785, q=98 ncpus=2)
task:kworker/1:2 state:R running task stack:26536 pid:90 tgid:90 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: events_power_efficient gc_worker
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x62/0x330 kernel/locking/lockdep.c:5872
Code: 56 18 12 83 f8 07 0f 87 a2 02 00 00 89 c0 48 0f a3 05 82 87 ee 0e 0f 82 74 02 00 00 8b 35 1a b8 ee 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 99 56 18 12 0f 85 ad 02 00 00 48 83 c4
RSP: 0018:ffffc9000266fa60 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3c9620 RCX: 000000005dbb888f
RDX: 0000000000000000 RSI: ffffffff8daa5c73 RDI: ffffffff8bf2a800
RBP: 0000000000000002 R08: 00000000149d0f48 R09: 000000008149d0f4
R10: 0000000000000002 R11: ffff88801c7cd4b0 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
gc_worker+0x241/0x16e0 net/netfilter/nf_conntrack_core.c:1546
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
task:sshd-session state:R running task stack:26520 pid:5830 tgid:5830 ppid:5828 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:60 [inline]
RIP: 0010:stack_access_ok+0x99/0x200 arch/x86/kernel/unwind_orc.c:393
Code: b6 04 02 84 c0 74 08 3c 03 0f 8e 0b 01 00 00 8b 13 85 d2 74 23 49 39 ef 77 1e 48 39 e9 76 19 4a 8d 54 25 00 49 39 d7 0f 92 c0 <48> 39 d1 0f 93 c2 20 d0 0f 85 ba 00 00 00 48 8d 7b 28 48 8d 4b 20
RSP: 0018:ffffc900035573f8 EFLAGS: 00000297
RAX: 0000000000000001 RBX: ffffc900035574a8 RCX: ffffc90003558000
RDX: ffffc90003557bb8 RSI: ffffc90003557bb0 RDI: ffffc900035574a8
RBP: ffffc90003557bb0 R08: 0000000000000001 R09: 000000005f832f42
R10: 0000000000000002 R11: 000000000008db7c R12: 0000000000000008
R13: ffffc900035574b8 R14: ffffc900035574b0 R15: ffffc90003550000
deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline]
unwind_next_frame+0x15c5/0x20a0 arch/x86/kernel/unwind_orc.c:648
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
unpoison_slab_object mm/kasan/common.c:339 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:365
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_node_noprof+0x298/0x800 mm/slub.c:5315
__alloc_skb+0x156/0x410 net/core/skbuff.c:679
alloc_skb_fclone include/linux/skbuff.h:1433 [inline]
tcp_stream_alloc_skb+0x34/0x670 net/ipv4/tcp.c:910
tcp_sendmsg_locked+0x12de/0x42a0 net/ipv4/tcp.c:1217
tcp_sendmsg+0x2e/0x50 net/ipv4/tcp.c:1412
inet_sendmsg+0xb9/0x140 net/ipv4/af_inet.c:859
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
sock_write_iter+0x509/0x610 net/socket.c:1195
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x7d3/0x11d0 fs/read_write.c:686
ksys_write+0x1f8/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f29f94a7407
RSP: 002b:00007ffe6386beb0 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f29f9c0e300 RCX: 00007f29f94a7407
RDX: 0000000000000034 RSI: 0000560f00cfb0b0 RDI: 0000000000000004
RBP: 0000560f00cfebe0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000001
R13: 00007ffe6386c000 R14: 0000000000000000 R15: 0000000000000004
rcu: rcu_preempt kthread starved for 10568 jiffies! g7785 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:28168 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 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:
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 10/25/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 26 60 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 13 d9 12 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197de8 EFLAGS: 000002c6
RAX: 000000000009d667 RBX: 0000000000000001 RCX: ffffffff8b7786d9
RDX: 0000000000000000 RSI: ffffffff8dacbd07 RDI: ffffffff8bf2a800
RBP: ffffed1003bd9498 R08: 0000000000000001 R09: ffffed10170a673d
R10: ffff8880b85339eb R11: ffff88801decaff0 R12: 0000000000000001
R13: ffff88801deca4c0 R14: ffffffff908880d0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881249fb000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f564a41e0d0 CR3: 0000000077797000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x38d/0x510 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x148