rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13635/2:b..l P19094/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=83765, q=531 ncpus=2)
task:syz.2.4244 state:D stack:24872 pid:19094 tgid:19094 ppid:5597 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x16dc/0x5500 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule_rtlock+0x30/0x70 kernel/sched/core.c:7390
rtlock_slowlock_locked+0x35c5/0x3c20 kernel/locking/rtmutex.c:1895
rtlock_slowlock kernel/locking/rtmutex.c:1922 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x165/0x400 kernel/locking/spinlock_rt.c:57
spin_lock_bh include/linux/spinlock_rt.h:90 [inline]
lock_sock_nested+0x7e/0x130 net/core/sock.c:3847
lock_sock include/net/sock.h:1713 [inline]
tipc_release+0xc4/0x2500 net/tipc/socket.c:639
__sock_release net/socket.c:710 [inline]
sock_close+0xad/0x220 net/socket.c:1501
__fput+0x42a/0xa80 fs/file_table.c:512
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
exit_to_user_mode_loop+0x1fa/0x730 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+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4991aae019
RSP: 002b:00007ffc1ae6dfa8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f4991d37da0 RCX: 00007f4991aae019
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f4991d37da0 R08: 0000000000000006 R09: 0000000000000000
R10: 00007f4991d37cb0 R11: 0000000000000246 R12: 0000000000151bdf
R13: 00007f4991d3609c R14: 0000000000151935 R15: 00007ffc1ae6e0b0
task:kworker/u8:15 state:R running task stack:22568 pid:13635 tgid:13635 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: tipc_send tipc_conn_send_work
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x16dc/0x5500 kernel/sched/core.c:7234
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:679
RIP: 0010:skb_release_head_state+0x0/0x360 net/core/skbuff.c:1170
Code: c7 04 24 01 00 00 00 e9 45 ff ff ff e8 39 d0 b4 f8 90 0f 0b 90 eb 96 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <0f> 1f 40 d6 55 41 57 41 56 41 55 41 54 53 48 89 fb 49 bc 00 00 00
RSP: 0018:ffffc900051060f0 EFLAGS: 00000293
RAX: ffffffff8911102c RBX: ffff88803d89cf00 RCX: ffff88803ba45d00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88803d89cf00
RBP: ffffc90005106270 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f5f467 R12: ffffc900051064e0
R13: ffff88803d89cfd8 R14: dffffc0000000000 R15: dffffc0000000000
skb_release_all net/core/skbuff.c:1195 [inline]
__kfree_skb+0x24/0x210 net/core/skbuff.c:1211
kfree_skb_reason include/linux/skbuff.h:1323 [inline]
kfree_skb include/linux/skbuff.h:1332 [inline]
tipc_sk_proto_rcv+0x7a1/0x1810 net/tipc/socket.c:2185
tipc_sk_filter_rcv+0x3005/0x3240 net/tipc/socket.c:2357
tipc_sk_enqueue net/tipc/socket.c:2450 [inline]
tipc_sk_rcv+0x8c4/0x2b30 net/tipc/socket.c:2502
tipc_node_xmit+0x218/0xf10 net/tipc/node.c:1701
tipc_node_xmit_skb net/tipc/node.c:1766 [inline]
tipc_node_distr_xmit+0x2da/0x420 net/tipc/node.c:1781
tipc_sk_rcv+0x273c/0x2b30 net/tipc/socket.c:2506
tipc_node_xmit+0x218/0xf10 net/tipc/node.c:1701
tipc_node_xmit_skb net/tipc/node.c:1766 [inline]
tipc_node_distr_xmit+0x2da/0x420 net/tipc/node.c:1781
tipc_sk_rcv+0x273c/0x2b30 net/tipc/socket.c:2506
tipc_topsrv_kern_evt net/tipc/topsrv.c:630 [inline]
tipc_conn_send_to_sock net/tipc/topsrv.c:286 [inline]
tipc_conn_send_work+0x6cd/0xa50 net/tipc/topsrv.c:306
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g83765 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=53388
rcu: rcu_preempt kthread starved for 10502 jiffies! g83765 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27784 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x16dc/0x5500 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 19098 Comm: syz.2.4244 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:check_preemption_disabled+0x29/0xe0 lib/smp_processor_id.c:19
Code: 90 55 41 57 41 56 53 65 8b 05 d7 fd 59 07 65 8b 0d cc fd 59 07 f7 c1 ff ff ff 7f 74 0c 5b 41 5e 41 5f 5d c3 cc cc cc cc cc 9c <59> f7 c1 00 02 00 00 74 ea 65 4c 8b 3d 7e fd 59 07 41 f6 47 2f 04
RSP: 0018:ffffc90003de7240 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff888038141f00 RCX: 0000000080000000
RDX: 0000000000000006 RSI: ffffffff8daf6ba4 RDI: ffffffff8bca7880
RBP: 1ffff1100702855e R08: ffffffff8fafa337 R09: 1ffffffff1f5f466
R10: dffffc0000000000 R11: fffffbfff1f5f467 R12: ffff888038142b30
R13: dffffc0000000000 R14: ffff888038142b30 R15: 0000000000000001
FS: 00007f498fce56c0(0000) GS:ffff888125c3e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c338339 CR3: 00000000294a8000 CR4: 00000000003526f0
Call Trace:
lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
lockdep_hardirqs_on_prepare+0x19c/0x270 kernel/locking/lockdep.c:4411
trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:78
__local_bh_enable_ip+0x1ae/0x2b0 kernel/softirq.c:306
local_bh_enable include/linux/bottom_half.h:33 [inline]
rt_spin_trylock_bh+0x1dd/0x2e0 kernel/locking/spinlock_rt.c:146
tipc_sk_rcv+0x487/0x2b30 net/tipc/socket.c:2501
tipc_node_xmit+0x218/0xf10 net/tipc/node.c:1701
tipc_node_xmit_skb net/tipc/node.c:1766 [inline]
tipc_node_distr_xmit+0x2da/0x420 net/tipc/node.c:1781
tipc_group_join+0x571/0x710 net/tipc/group.c:208
tipc_sk_join+0x480/0x6a0 net/tipc/socket.c:3107
tipc_setsockopt+0x73e/0x9a0 net/tipc/socket.c:3205
do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2368
__sys_setsockopt net/socket.c:2393 [inline]
__do_sys_setsockopt net/socket.c:2399 [inline]
__se_sys_setsockopt net/socket.c:2396 [inline]
__x64_sys_setsockopt+0x143/0x1b0 net/socket.c:2396
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4991aae019
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f498fce5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f4991d36090 RCX: 00007f4991aae019
RDX: 0000000000000087 RSI: 000000000000010f RDI: 0000000000000006
RBP: 00007f4991b4500c R08: 0000000000000010 R09: 0000000000000000
R10: 0000200000000440 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4991d36128 R14: 00007f4991d36090 R15: 00007ffc1ae6de48