rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=a4a4/0/0x1 softirq=112196/112197 fqs=420
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P16835/1:b..l P25141/1:b..l P25158/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=159669, q=84 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x41/0xc0 kernel/rcu/tree.c:752
Code: 0a 94 89 c5 83 f8 07 0f 87 82 00 00 00 48 8d 3c ed 20 19 1c 8e 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 <75> 5c 48 03 1c ed 20 19 1c 8e 48 b8 00 00 00 00 00 fc ff df 48 89
RSP: 0018:ffffc90000007d28 EFLAGS: 00000046
RAX: dffffc0000000000 RBX: ffffffff940acda8 RCX: 0000000000000002
RDX: 1ffffffff1c38324 RSI: ffffffff8c1c4700 RDI: ffffffff8e1c1920
RBP: 0000000000000000 R08: 0000000000000001 R09: fffff52000000fa2
R10: 0000000000000003 R11: 0000000000000001 R12: 0000000000000001
R13: dffffc0000000000 R14: ffff888037a91300 R15: 1ffff92000000fb6
FS: 0000000000000000(0000) GS:ffff888124387000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000013000 CR3: 000000008ae70000 CR4: 00000000003526f0
Call Trace:
trace_lock_release include/trace/events/lock.h:69 [inline]
lock_release+0x245/0x310 kernel/locking/lockdep.c:5879
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:176 [inline]
_raw_spin_unlock_irqrestore+0x1a/0x80 kernel/locking/spinlock.c:198
debug_object_deactivate+0x2e4/0x3b0 lib/debugobjects.c:915
debug_hrtimer_deactivate kernel/time/hrtimer.c:490 [inline]
__run_hrtimer kernel/time/hrtimer.c:1898 [inline]
__hrtimer_run_queues+0x2f0/0xa00 kernel/time/hrtimer.c:1994
hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: a6 92 02 e9 43 44 03 00 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 23 02 22 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e407e00 EFLAGS: 00000246
RAX: 0000000005dce203 RBX: ffffffff8e4955c0 RCX: ffffffff8b899225
RDX: 0000000000000000 RSI: ffffffff8df0fbf5 RDI: ffffffff8c1c4780
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10170867b5
R10: ffff8880b8433dab R11: 0000000000000000 R12: 0000000000000000
R13: fffffbfff1c92ab8 R14: 0000000000000000 R15: ffffffff90d71a50
arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x464/0x590 kernel/sched/idle.c:352
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451
rest_init+0x251/0x260 init/main.c:762
start_kernel+0x484/0x490 init/main.c:1220
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148
task:syz.2.5102 state:R running task stack:26808 pid:25158 tgid:25156 ppid:5621 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7370
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:190
spin_unlock include/linux/spinlock.h:390 [inline]
insert_pages+0x390/0x5e0 mm/memory.c:2473
vm_insert_pages mm/memory.c:2514 [inline]
vm_insert_pages+0x138/0x440 mm/memory.c:2500
io_region_mmap io_uring/memmap.c:292 [inline]
io_uring_mmap+0x4c7/0x523 io_uring/memmap.c:318
vfs_mmap include/linux/fs.h:2071 [inline]
mmap_file mm/internal.h:168 [inline]
__mmap_new_file_vma mm/vma.c:2496 [inline]
__mmap_new_vma mm/vma.c:2562 [inline]
__mmap_region+0x13e1/0x2dd0 mm/vma.c:2771
mmap_region+0x527/0x620 mm/vma.c:2857
do_mmap+0xc63/0x12f0 mm/mmap.c:560
vm_mmap_pgoff+0x29e/0x470 mm/util.c:581
ksys_mmap_pgoff+0x3cb/0x610 mm/mmap.c:606
__do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
__se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
__x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff6fbb9cbc2
RSP: 002b:00007ff6fcab2fa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff6fbb9cbc2
RDX: 0000000000000003 RSI: 0000000000100000 RDI: 0000000000000000
RBP: 0000000000008001 R08: 0000000000000006 R09: 0000000010000000
R10: 0000000000008001 R11: 0000000000000246 R12: 00002000000003c0
R13: 0000200000000000 R14: 00002000000001c0 R15: 00007fff319827d8
task:syz.3.5097 state:R running task stack:26552 pid:25141 tgid:25139 ppid:5617 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x205/0x970 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872
Code: 05 fb 03 25 12 83 f8 07 0f 87 d9 02 00 00 48 0f a3 05 06 8e f2 0e 0f 82 a4 02 00 00 8b 35 8e c1 f2 0e 85 f6 0f 85 bf 00 00 00 <48> 8b 44 24 30 65 48 2b 05 9d 03 25 12 0f 85 ed 02 00 00 48 83 c4
RSP: 0018:ffffc9000db37050 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8deea69a RDI: ffffffff8c1c4780
RBP: ffffffff8e7e5560 R08: 00000000b1ffeb51 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:838 [inline]
class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4570 [inline]
slab_alloc_node mm/slub.c:4899 [inline]
kmem_cache_alloc_noprof+0x241/0x6e0 mm/slub.c:4906
__kernfs_new_node+0xd2/0x9f0 fs/kernfs/dir.c:664
kernfs_new_node+0x11b/0x1a0 fs/kernfs/dir.c:748
__kernfs_create_file+0x53/0x350 fs/kernfs/file.c:1057
sysfs_add_file_mode_ns+0x207/0x3c0 fs/sysfs/file.c:313
create_files fs/sysfs/group.c:82 [inline]
internal_create_group+0x593/0xfb0 fs/sysfs/group.c:189
internal_create_groups+0x9d/0x150 fs/sysfs/group.c:229
device_add_groups drivers/base/core.c:2837 [inline]
device_add_attrs drivers/base/core.c:2901 [inline]
device_add+0x71a/0x1950 drivers/base/core.c:3645
netdev_register_kobject+0x1a9/0x3d0 net/core/net-sysfs.c:2343
register_netdevice+0x151c/0x24b0 net/core/dev.c:11423
__ip_tunnel_create+0x52b/0x670 net/ipv4/ip_tunnel.c:268
ip_tunnel_init_net+0x230/0x780 net/ipv4/ip_tunnel.c:1147
ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137
setup_net+0x118/0x3a0 net/core/net_namespace.c:446
copy_net_ns+0x46f/0x7c0 net/core/net_namespace.c:579
create_new_namespaces+0x3ea/0xac0 kernel/nsproxy.c:132
unshare_nsproxy_namespaces+0xf2/0x220 kernel/nsproxy.c:234
ksys_unshare+0x438/0xab0 kernel/fork.c:3242
__do_sys_unshare kernel/fork.c:3316 [inline]
__se_sys_unshare kernel/fork.c:3314 [inline]
__x64_sys_unshare+0x31/0x40 kernel/fork.c:3314
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd2eeb9ce59
RSP: 002b:00007fd2efb16028 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fd2eee15fa0 RCX: 00007fd2eeb9ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000068040200
RBP: 00007fd2eec32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd2eee16038 R14: 00007fd2eee15fa0 R15: 00007fff19e7c168
task:kworker/u8:15 state:R running task stack:24056 pid:16835 tgid:16835 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: krds_cp_wq#6/3 rds_connect_worker
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x205/0x970 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:rol32 include/linux/bitops.h:126 [inline]
RIP: 0010:jhash2 include/linux/jhash.h:129 [inline]
RIP: 0010:__ipv6_addr_jhash include/net/ipv6.h:677 [inline]
RIP: 0010:inet6_addr_hash.isra.0+0xb7/0x1c0 net/ipv6/addrconf.c:1025
Code: f3 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 e2 00 00 00 8b 45 08 48 8d 7d 0c 01 c6 41 29 c4 89 f2 01 de c2 04 44 31 e2 89 d0 29 d3 8d 0c 32 c1 c0 06 31 d8 89 c2 29 c6
RSP: 0018:ffffc900052a7818 EFLAGS: 00000a92
RAX: 0000000000000000 RBX: 0000000073e060bd RCX: 0000000000000000
RDX: 0000000073e060bd RSI: 00000000e7c0c17a RDI: ffffc900052a79d4
RBP: ffffc900052a79c8 R08: 0000000000000000 R09: 0000000000000040
R10: 0000000000000000 R11: 0000000000000000 R12: 00000000000080fe
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000009389
__ipv6_chk_addr_and_flags+0x6f/0x750 net/ipv6/addrconf.c:1982
ipv6_chk_addr_and_flags net/ipv6/addrconf.c:2022 [inline]
ipv6_chk_addr+0x3a/0x50 net/ipv6/addrconf.c:1963
__inet6_bind+0x1236/0x1b40 net/ipv6/af_inet6.c:367
inet6_bind_sk net/ipv6/af_inet6.c:449 [inline]
inet6_bind_sk net/ipv6/af_inet6.c:426 [inline]
inet6_bind+0xdb/0x120 net/ipv6/af_inet6.c:455
kernel_bind+0xff/0x160 net/socket.c:3660
rds_tcp_conn_path_connect+0x554/0xaa0 net/rds/tcp_connect.c:175
rds_connect_worker+0x1b4/0x2d0 net/rds/threads.c:176
process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314
process_scheduled_works kernel/workqueue.c:3397 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478
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: rcu_preempt kthread starved for 9662 jiffies! g159669 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:27848 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
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+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: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: a6 92 02 e9 43 44 03 00 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 23 02 22 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df0 EFLAGS: 00000242
RAX: 0000000008589257 RBX: ffff88801e2b2540 RCX: ffffffff8b899225
RDX: 0000000000000000 RSI: ffffffff8df0fbf5 RDI: ffffffff8c1c4780
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10170a67b5
R10: ffff8880b8533dab R11: 0000000000000000 R12: 0000000000000001
R13: ffffed1003c564a8 R14: 0000000000000001 R15: ffffffff90d71a50
FS: 0000000000000000(0000) GS:ffff888124487000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002000 CR3: 00000000788ea000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x464/0x590 kernel/sched/idle.c:352
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x148