rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P20048/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=87993, q=2255 ncpus=2)
task:syz.3.3853 state:R running task stack:26872 pid:20048 tgid:20047 ppid:5608 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7228
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7552
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+0x205/0xa00 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872
Code: 05 7b 80 2e 12 83 f8 07 0f 87 da 00 00 00 48 0f a3 05 c6 74 f6 0e 0f 82 ac 02 00 00 8b 35 8e a8 f6 0e 85 f6 0f 85 c7 00 00 00 <48> 8b 44 24 30 65 48 2b 05 1d 80 2e 12 0f 85 ec 02 00 00 48 83 c4
RSP: 0018:ffffc900068af9a0 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8df33a44 RDI: ffffffff8c1e7180
RBP: ffffffff8e7e60c0 R08: 00000000da95f748 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:840 [inline]
__page_table_check_zero+0x8c/0x410 mm/page_table_check.c:138
page_table_check_free include/linux/page_table_check.h:46 [inline]
__free_pages_prepare mm/page_alloc.c:1407 [inline]
__free_frozen_pages+0x790/0x1090 mm/page_alloc.c:2950
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4612 [inline]
slab_alloc_node mm/slub.c:4945 [inline]
__kmalloc_cache_noprof+0x265/0x6c0 mm/slub.c:5511
_kmalloc_noprof include/linux/slab.h:969 [inline]
_kzalloc_noprof include/linux/slab.h:1290 [inline]
ref_tracker_alloc+0x190/0x590 lib/ref_tracker.c:270
__netns_tracker_alloc include/net/net_namespace.h:367 [inline]
netns_tracker_alloc include/net/net_namespace.h:376 [inline]
get_net_track include/net/net_namespace.h:393 [inline]
sk_alloc+0x2e9/0xe80 net/core/sock.c:2325
__netlink_create+0x5e/0x2c0 net/netlink/af_netlink.c:627
netlink_create+0x29b/0x610 net/netlink/af_netlink.c:685
__sock_create+0x339/0x860 net/socket.c:1651
sock_create net/socket.c:1709 [inline]
__sys_socket_create net/socket.c:1746 [inline]
__sys_socket+0x14d/0x260 net/socket.c:1793
__do_sys_socket net/socket.c:1807 [inline]
__se_sys_socket net/socket.c:1805 [inline]
__x64_sys_socket+0x72/0xb0 net/socket.c:1805
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: 0033:0x7f07d619ce59
RSP: 002b:00007f07d43f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 00007f07d6415fa0 RCX: 00007f07d619ce59
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000010
RBP: 00007f07d6232e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f07d6416038 R14: 00007f07d6415fa0 R15: 00007ffd0e22df98
rcu: rcu_preempt kthread starved for 1297 jiffies! g87993 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27432 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7322
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: 0 UID: 0 PID: 9468 Comm: kworker/u8:28 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: krds_cp_wq#12/2 rds_connect_worker
RIP: 0010:stack_trace_consume_entry+0x9a/0x170 kernel/stacktrace.c:93
Code: 8d 7b 0c 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 98 00 00 00 8b 43 0c 85 c0 75 57 <48> b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 80 3c 02 00 0f
RSP: 0018:ffffc90000007618 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc900000076f8 RCX: ffffc9000000758c
RDX: 0000000000000000 RSI: ffffffff896a558a RDI: ffffc90000007704
RBP: 0000000000000004 R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000016e4c R12: ffffffff81f38c60
R13: ffffc900000076f8 R14: 0000000000000000 R15: ffff888034b12540
FS: 0000000000000000(0000) GS:ffff8881242e7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f07d43b4d58 CR3: 000000002ab90000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
arch_stack_walk+0x88/0xf0 arch/x86/kernel/stacktrace.c:27
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:4612 [inline]
slab_alloc_node mm/slub.c:4945 [inline]
kmem_cache_alloc_noprof+0x26b/0x6a0 mm/slub.c:4959
skb_ext_maybe_cow net/core/skbuff.c:7112 [inline]
skb_ext_add+0xfa/0x810 net/core/skbuff.c:7187
can_can_gw_rcv net/can/gw.c:520 [inline]
can_can_gw_rcv+0x464/0xca0 net/can/gw.c:458
deliver net/can/af_can.c:575 [inline]
can_rcv_filter+0x153/0x890 net/can/af_can.c:602
can_receive+0x2cb/0x500 net/can/af_can.c:674
can_rcv+0x29e/0x300 net/can/af_can.c:699
__netif_receive_skb_one_core+0x1b2/0x1e0 net/core/dev.c:6206
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6319
process_backlog+0x37a/0x1580 net/core/dev.c:6670
__napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7729
napi_poll net/core/dev.c:7792 [inline]
net_rx_action+0xa40/0xf20 net/core/dev.c:7949
handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622
do_softirq kernel/softirq.c:523 [inline]
do_softirq+0xac/0xe0 kernel/softirq.c:510
__local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450
__inet6_bind+0x8b1/0x1b40 net/ipv6/af_inet6.c:419
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:3646
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+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