rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6316/1:b..l P5156/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=15209, q=676 ncpus=2)
task:udevd state:R running task stack:25160 pid:5156 ppid:1 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:unwind_next_frame+0x5/0x2970 arch/x86/kernel/unwind_orc.c:469
Code: b5 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 64 ff ff ff 48 89 df e8 ac 3f a2 00 e9 57 ff ff ff 0f 1f 80 00 00 00 00 f3 0f 1e fa 55 <41> 57 41 56 41 55 41 54 53 48 81 ec 98 00 00 00 49 89 fc 49 bd 00
RSP: 0018:ffffc900032f74f8 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffc900032f75c0 RCX: ffff88807e2c3c00
RDX: dffffc0000000000 RSI: ffffffff817467ac RDI: ffffc900032f7508
RBP: ffffc900032f7590 R08: ffffc900032f75d0 R09: 0000000000000000
R10: 0000000000000004 R11: 0000000000000000 R12: ffffffff817467ac
R13: 1ffff9200065eecc R14: ffffffff817467f0 R15: ffffc900032f7508
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf7/0x1f0 mm/page_owner.c:128
__reset_page_owner+0x4e/0x190 mm/page_owner.c:149
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1154 [inline]
free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
__slab_free+0x35e/0x410 mm/slub.c:3736
qlink_free mm/kasan/quarantine.c:166 [inline]
qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
slab_alloc_node mm/slub.c:3495 [inline]
__kmem_cache_alloc_node+0x13e/0x260 mm/slub.c:3534
__do_kmalloc_node mm/slab_common.c:1006 [inline]
__kmalloc+0xa4/0x240 mm/slab_common.c:1020
kmalloc include/linux/slab.h:604 [inline]
tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_perm+0x20f/0x4b0 security/tomoyo/file.c:822
security_inode_getattr+0xd3/0x120 security/security.c:2153
vfs_getattr fs/stat.c:173 [inline]
vfs_fstat fs/stat.c:198 [inline]
__do_sys_newfstat fs/stat.c:473 [inline]
__se_sys_newfstat fs/stat.c:470 [inline]
__x64_sys_newfstat+0x101/0x1f0 fs/stat.c:470
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3ad3b11ad7
RSP: 002b:00007ffccf178f58 EFLAGS: 00000206 ORIG_RAX: 0000000000000005
RAX: ffffffffffffffda RBX: 000000000000000d RCX: 00007f3ad3b11ad7
RDX: 0000000000090800 RSI: 00007ffccf178f60 RDI: 000000000000000d
RBP: 00007ffccf178f60 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000206 R12: 000055a11875e7b0
R13: 00000000000000ff R14: 000055a0eb6afbe0 R15: 00007ffccf179280
task:syz-executor state:R running task stack:21288 pid:6316 ppid:6311 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866
preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890
preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
vprintk_emit+0x578/0x600 kernel/printk/printk.c:2342
dev_vprintk_emit+0x338/0x3e0 drivers/base/core.c:4953
dev_printk_emit+0xe1/0x130 drivers/base/core.c:4964
__netdev_printk+0x3bf/0x4a0 net/core/dev.c:11482
netdev_info+0x10b/0x160 net/core/dev.c:11537
nsim_udp_tunnel_set_port+0x297/0x440 drivers/net/netdevsim/udp_tunnels.c:34
udp_tunnel_nic_device_sync_one net/ipv4/udp_tunnel_nic.c:-1 [inline]
udp_tunnel_nic_device_sync_by_port net/ipv4/udp_tunnel_nic.c:246 [inline]
__udp_tunnel_nic_device_sync+0xa70/0x1370 net/ipv4/udp_tunnel_nic.c:289
udp_tunnel_nic_device_sync net/ipv4/udp_tunnel_nic.c:312 [inline]
__udp_tunnel_nic_add_port+0xaf8/0xdb0 net/ipv4/udp_tunnel_nic.c:531
udp_tunnel_nic_add_port include/net/udp_tunnel.h:333 [inline]
udp_tunnel_notify_add_rx_port+0x28e/0x3e0 net/ipv4/udp_tunnel_core.c:127
geneve_socket_create drivers/net/geneve.c:614 [inline]
geneve_sock_add+0x55e/0x910 drivers/net/geneve.c:689
geneve_open+0xd2/0x140 drivers/net/geneve.c:731
__dev_open+0x2bc/0x430 net/core/dev.c:1506
__dev_change_flags+0x20e/0x6a0 net/core/dev.c:8685
dev_change_flags+0x88/0x1a0 net/core/dev.c:8757
do_setlink+0xc74/0x3fb0 net/core/rtnetlink.c:2905
__rtnl_newlink net/core/rtnetlink.c:3703 [inline]
rtnl_newlink+0x175b/0x2020 net/core/rtnetlink.c:3750
rtnetlink_rcv_msg+0x7c7/0xf10 net/core/rtnetlink.c:6475
netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2545
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
__sys_sendto+0x46a/0x620 net/socket.c:2201
__do_sys_sendto net/socket.c:2213 [inline]
__se_sys_sendto net/socket.c:2209 [inline]
__x64_sys_sendto+0xde/0xf0 net/socket.c:2209
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f06c7390d5c
RSP: 002b:00007ffed85fb070 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f06c8114620 RCX: 00007f06c7390d5c
RDX: 000000000000002c RSI: 00007f06c8114670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffed85fb0c4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f06c8114670 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10601 jiffies! g15209 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:27752 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 6686 Comm: syz.3.92 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202
Code: 00 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 2a 73 ef f6 48 89 df e8 42 45 f0 f6 e8 8d eb 13 f7 fb bf 01 00 00 00 52 6a e3 f6 65 8b 05 33 b5 8b 75 85 c0 74 02 5b c3 e8 50 99 88
RSP: 0018:ffffc9000474fc98 EFLAGS: 00000282
RAX: bc1406a43c4efc00 RBX: ffff888027eadc80 RCX: bc1406a43c4efc00
RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: 0000000000000001
RBP: ffff888027eae118 R08: ffffffff8e4a836f R09: 1ffffffff1c9506d
R10: dffffc0000000000 R11: fffffbfff1c9506e R12: 1ffff11004fd5c23
R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000
FS: 00007fc0fd2a06c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000005d9e0000 CR4: 00000000003506e0
Call Trace:
spin_unlock_irq include/linux/spinlock.h:401 [inline]
get_signal+0x11f5/0x1400 kernel/signal.c:2905
arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc0fc38eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc0fd2a0038 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007fc0fc5e5fa0 RCX: 00007fc0fc38eec9
RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fc0fc411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc0fc5e6038 R14: 00007fc0fc5e5fa0 R15: 00007ffc5b21e748
sched: RT throttling activated