rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6877/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=19337, q=512565 ncpus=2)
task:syz.2.283 state:R running task stack:26336 pid:6877 tgid:6870 ppid:5855 task_flags:0x400040 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x1b88/0x5240 kernel/sched/core.c:6767
preempt_schedule_notrace+0x103/0x140 kernel/sched/core.c:7040
preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
rcu_is_watching+0x7e/0xb0 kernel/rcu/tree.c:737
rcu_read_unlock include/linux/rcupdate.h:869 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x1a5b/0x23b0 arch/x86/kernel/unwind_orc.c:680
arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2389 [inline]
slab_free mm/slub.c:4646 [inline]
kfree+0x198/0x430 mm/slub.c:4845
io_clean_op+0x389/0x400 io_uring/io_uring.c:423
io_free_batch_list io_uring/io_uring.c:1424 [inline]
__io_submit_flush_completions+0xbd7/0xce0 io_uring/io_uring.c:1465
io_submit_flush_completions io_uring/io_uring.h:165 [inline]
io_submit_state_end io_uring/io_uring.c:2239 [inline]
io_submit_sqes+0x185b/0x1ce0 io_uring/io_uring.c:2357
__do_sys_io_uring_enter io_uring/io_uring.c:3402 [inline]
__se_sys_io_uring_enter+0x2cd/0x3560 io_uring/io_uring.c:3336
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f40c8d8d169
RSP: 002b:00007f40c9c67038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007f40c8fa6160 RCX: 00007f40c8d8d169
RDX: 0000000000000000 RSI: 0000000000003516 RDI: 0000000000000008
RBP: 00007f40c8e0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f40c8fa6160 R15: 00007f40c90cfa28
rcu: rcu_preempt kthread starved for 8231 jiffies! g19337 f0x2 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:26952 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x1b88/0x5240 kernel/sched/core.c:6767
preempt_schedule_irq+0xfe/0x1c0 kernel/sched/core.c:7090
irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__debug_object_init+0x0/0x480 lib/debugobjects.c:732
Code: cd fa 53 0b 00 74 05 c3 cc cc cc cc 31 d2 eb 1a 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48
RSP: 0018:ffffc90000157ab8 EFLAGS: 00000246
RAX: ffffffff81afd22e RBX: ffffc90000157b20 RCX: ffff88801c68da00
RDX: 0000000000000001 RSI: ffffffff8c4cc760 RDI: ffffc90000157b20
RBP: ffffc90000157bf0 R08: ffffffff9a7806a0 R09: 0000000000000000
R10: ffffc90000157b20 R11: fffff5200002af6e R12: ffffffff81b0d5c0
R13: 0000000000000000 R14: dffffc0000000000 R15: ffffffff8c4cdde0
init_timer_on_stack_key+0x3d/0x110 kernel/time/timer.c:858
schedule_timeout+0x132/0x2b0 kernel/time/sleep_timeout.c:96
rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046
rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248
kthread+0x7b7/0x940 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
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: 0 Comm: swapper/0 Not tainted 6.15.0-rc1-syzkaller-00025-gbec7dcbc242c #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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:arch_irqs_disabled arch/x86/include/asm/irqflags.h:151 [inline]
RIP: 0010:lock_release+0x224/0x3e0 kernel/locking/lockdep.c:5890
Code: c7 3d d5 4f 8e e8 7c 9f 91 0a b8 ff ff ff ff 65 0f c1 05 ef da c9 11 83 f8 01 0f 85 bf 00 00 00 48 c7 44 24 20 00 00 00 00 9c <8f> 44 24 20 f7 44 24 20 00 02 00 00 0f 85 c3 00 00 00 41 f7 c6 00
RSP: 0018:ffffc90000006af8 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffffffff9368a020 RCX: 0000000000000003
RDX: dffffc0000000000 RSI: ffffffff8e4fd53d RDI: ffffffff8ca1b6a0
RBP: ffffffff8ea970e8 R08: ffffffff8ea07ca8 R09: 0000000000000000
R10: ffffc90000006c90 R11: fffff52000000d94 R12: 0000000000000003
R13: ffffffff8ea96580 R14: 0000000000000206 R15: ffffffff8ed3dfe0
FS: 0000000000000000(0000) GS:ffff888124f96000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5912d3c450 CR3: 000000007b456000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x1a9f/0x23b0 arch/x86/kernel/unwind_orc.c:680
arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2389 [inline]
slab_free mm/slub.c:4646 [inline]
kmem_cache_free+0x197/0x410 mm/slub.c:4748
skb_kfree_head net/core/skbuff.c:1056 [inline]
skb_free_head net/core/skbuff.c:1070 [inline]
skb_release_data+0x67a/0x8b0 net/core/skbuff.c:1097
skb_release_all net/core/skbuff.c:1162 [inline]
__kfree_skb net/core/skbuff.c:1176 [inline]
consume_skb+0x9f/0xf0 net/core/skbuff.c:1408
nft_synproxy_eval_v6 net/netfilter/nft_synproxy.c:-1 [inline]
nft_synproxy_do_eval+0x755/0xa90 net/netfilter/nft_synproxy.c:145
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x4b2/0x1db0 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x41f/0x6b0 net/netfilter/nft_chain_filter.c:161
nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
nf_hook_slow+0xc8/0x220 net/netfilter/core.c:626
nf_hook include/linux/netfilter.h:269 [inline]
NF_HOOK+0x29b/0x450 include/linux/netfilter.h:312
ip6_input+0x169/0x270 net/ipv6/ip6_input.c:491
NF_HOOK+0x3a0/0x450 include/linux/netfilter.h:314
__netif_receive_skb_one_core net/core/dev.c:5894 [inline]
__netif_receive_skb+0x1ef/0x670 net/core/dev.c:6007
process_backlog+0x664/0x15c0 net/core/dev.c:6359
__napi_poll+0xcb/0x480 net/core/dev.c:7331
napi_poll net/core/dev.c:7395 [inline]
net_rx_action+0x89d/0x1240 net/core/dev.c:7517
handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0xfb/0x220 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81
Code: cc cc cc cc 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 13 a1 17 00 f3 0f 1e fa fb f4 cc cc cc cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8ea07d60 EFLAGS: 000002c6
RAX: cfab7fbfecbe7900 RBX: ffffffff8197af7e RCX: ffffffff8c30995c
RDX: 0000000000000001 RSI: ffffffff8e69c6c2 RDI: ffffffff8ca1b6a0
RBP: ffffffff8ea07eb8 R08: ffff8880b8632b5b R09: 1ffff110170c656b
R10: dffffc0000000000 R11: ffffed10170c656c R12: 1ffffffff1d40fc6
R13: 1ffffffff1d52cb0 R14: 0000000000000000 R15: dffffc0000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:748
default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
cpuidle_idle_call kernel/sched/idle.c:185 [inline]
do_idle+0x22e/0x5d0 kernel/sched/idle.c:325
cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:423
rest_init+0x2dc/0x300 init/main.c:743
start_kernel+0x484/0x510 init/main.c:1099
x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:513
x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:494
common_startup_64+0x13e/0x147