rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11872/4:b..l
rcu: (detected by 1, t=10503 jiffies, g=59573, q=2826 ncpus=2)
task:syz.5.1485 state:R running task stack:24280 pid:11872 tgid:11866 ppid:10646 task_flags:0x400140 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__local_bh_enable_ip+0x13e/0x1c0 kernel/softirq.c:457
spin_unlock_bh include/linux/spinlock.h:396 [inline]
sctp_to_nlattr+0x1fb/0x3f0 net/netfilter/nf_conntrack_proto_sctp.c:574
ctnetlink_dump_protoinfo+0x154/0x230 net/netfilter/nf_conntrack_netlink.c:213
ctnetlink_conntrack_event+0xcdb/0x1490 net/netfilter/nf_conntrack_netlink.c:828
__nf_conntrack_eventmask_report+0x1fa/0x480 net/netfilter/nf_conntrack_ecache.c:148
nf_ct_deliver_cached_events+0x1fc/0x2d0 net/netfilter/nf_conntrack_ecache.c:237
nf_conntrack_confirm include/net/netfilter/nf_conntrack_core.h:69 [inline]
nf_confirm+0x9f2/0xd90 net/netfilter/nf_conntrack_proto.c:-1
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
nf_hook+0x217/0x380 include/linux/netfilter.h:273
NF_HOOK_COND include/linux/netfilter.h:306 [inline]
ip_output+0x269/0x450 net/ipv4/ip_output.c:438
ip_local_out net/ipv4/ip_output.c:131 [inline]
__ip_queue_xmit+0x118d/0x1c30 net/ipv4/ip_output.c:534
sctp_packet_transmit+0x2581/0x2bb0 net/sctp/output.c:653
sctp_outq_flush_transports net/sctp/outqueue.c:1173 [inline]
sctp_outq_flush+0xecb/0x3140 net/sctp/outqueue.c:1221
sctp_cmd_interpreter net/sctp/sm_sideeffect.c:-1 [inline]
sctp_side_effects net/sctp/sm_sideeffect.c:1204 [inline]
sctp_do_sm+0x5332/0x5a20 net/sctp/sm_sideeffect.c:1175
sctp_primitive_REQUESTHEARTBEAT+0x98/0xc0 net/sctp/primitive.c:185
sctp_apply_peer_addr_params+0xdf/0x1880 net/sctp/socket.c:2437
sctp_setsockopt_peer_addr_params+0x678/0x940 net/sctp/socket.c:2687
sctp_setsockopt+0x709/0x1200 net/sctp/socket.c:4638
do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2360
__sys_setsockopt net/socket.c:2385 [inline]
__do_sys_setsockopt net/socket.c:2391 [inline]
__se_sys_setsockopt net/socket.c:2388 [inline]
__x64_sys_setsockopt+0x13f/0x1b0 net/socket.c:2388
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f30f538efc9
RSP: 002b:00007f30f35d5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f30f55e6090 RCX: 00007f30f538efc9
RDX: 0000000000000009 RSI: 0000000000000084 RDI: 0000000000000006
RBP: 00007f30f5411f91 R08: 000000000000009c R09: 0000000000000000
R10: 0000200000000300 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f30f55e6128 R14: 00007f30f55e6090 R15: 00007f30f570fa28
rcu: rcu_preempt kthread starved for 1171 jiffies! g59573 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:27224 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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 10/02/2025
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 bb cc d0 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90000a07ad8 EFLAGS: 00000206
RAX: d1b1b3a879bdb200 RBX: 0000000000000000 RCX: d1b1b3a879bdb200
RDX: 0000000000000000 RSI: ffffffff8d8f29f0 RDI: ffffffff8bbf05e0
RBP: ffffffff81738d25 R08: 0000000000000000 R09: ffffffff81738d25
R10: ffffc90000a07c98 R11: ffffffff81ac2d30 R12: 0000000000000002
R13: ffffffff8df3d2e0 R14: 0000000000000000 R15: 0000000000000246
FS: 0000000000000000(0000) GS:ffff88812623e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e6a3f4f9a0 CR3: 00000000262d8000 CR4: 00000000003526f0
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
unpoison_slab_object mm/kasan/common.c:342 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4970 [inline]
slab_alloc_node mm/slub.c:5280 [inline]
kmem_cache_alloc_node_noprof+0x433/0x710 mm/slub.c:5332
__alloc_skb+0x112/0x2d0 net/core/skbuff.c:660
alloc_skb include/linux/skbuff.h:1383 [inline]
nlmsg_new include/net/netlink.h:1055 [inline]
fdb_notify+0xa6/0x160 net/bridge/br_fdb.c:188
br_fdb_update+0x4c8/0x690 net/bridge/br_fdb.c:1036
br_handle_frame_finish+0x587/0x1c50 net/bridge/br_input.c:144
br_nf_hook_thresh+0x3c6/0x4a0 net/bridge/br_netfilter_hooks.c:-1
br_nf_pre_routing_finish_ipv6+0x999/0xd60 net/bridge/br_netfilter_ipv6.c:-1
NF_HOOK include/linux/netfilter.h:318 [inline]
br_nf_pre_routing_ipv6+0x37e/0x6b0 net/bridge/br_netfilter_ipv6.c:184
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
br_handle_frame+0x982/0x14c0 net/bridge/br_input.c:442
__netif_receive_skb_core+0x10b9/0x4380 net/core/dev.c:5966
__netif_receive_skb_one_core net/core/dev.c:6077 [inline]
__netif_receive_skb+0x72/0x380 net/core/dev.c:6192
process_backlog+0x60e/0x14f0 net/core/dev.c:6544
__napi_poll+0xc7/0x360 net/core/dev.c:7594
napi_poll net/core/dev.c:7657 [inline]
net_rx_action+0x5f7/0xdf0 net/core/dev.c:7784
handle_softirqs+0x286/0x870 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc cc cc cc 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 33 21 22 00 f3 0f 1e fa fb f4 c8 e6 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: d1b1b3a879bdb200 RBX: ffffffff81967be7 RCX: d1b1b3a879bdb200
RDX: 0000000000000001 RSI: ffffffff8d70bf53 RDI: ffffffff8bbf05e0
RBP: ffffc90000197f10 R08: ffff8880b8932fdb R09: 1ffff110171265fb
R10: dffffc0000000000 R11: ffffed10171265fc R12: ffffffff8f7cd470
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110039d3b58
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x1e7/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x147