rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6798/1:b..l P5886/1:b..l P5190/1:b..l P6812/2:b..l
rcu: (detected by 1, t=10503 jiffies, g=17781, q=2362 ncpus=2)
task:syz.0.164 state:R running task stack:25944 pid:6812 tgid:6806 ppid:5829 task_flags:0x400040 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7113
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__local_bh_enable_ip+0x107/0x120 kernel/softirq.c:457
local_bh_enable include/linux/bottom_half.h:33 [inline]
ip6t_do_table+0xc02/0x1c30 net/ipv6/netfilter/ip6_tables.c:375
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623
nf_hook include/linux/netfilter.h:273 [inline]
__ip6_local_out+0x428/0xa80 net/ipv6/output_core.c:145
ip6_local_out+0x2e/0x4d0 net/ipv6/output_core.c:155
ip6_send_skb+0x112/0x460 net/ipv6/ip6_output.c:1994
udp_v6_send_skb+0x96f/0x1910 net/ipv6/udp.c:1440
udpv6_sendmsg+0x23b1/0x2d30 net/ipv6/udp.c:1731
inet6_sendmsg+0x105/0x140 net/ipv6/af_inet6.c:659
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0x705/0xc70 net/socket.c:2630
___sys_sendmsg+0x134/0x1d0 net/socket.c:2684
__sys_sendmmsg+0x200/0x420 net/socket.c:2773
__do_sys_sendmmsg net/socket.c:2800 [inline]
__se_sys_sendmmsg net/socket.c:2797 [inline]
__x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2797
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe49218f6c9
RSP: 002b:00007fe492fde038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fe4923e6180 RCX: 00007fe49218f6c9
RDX: 00000000000009a6 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007fe492211f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe4923e6218 R14: 00007fe4923e6180 R15: 00007fff7ef48318
task:klogd state:R running task stack:24936 pid:5190 tgid:5190 ppid:1 task_flags:0x400100 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
irqentry_exit+0x36/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x183/0x2f0 kernel/locking/lockdep.c:5893
Code: 0f c1 05 38 24 09 12 83 f8 01 0f 85 1d 01 00 00 9c 58 f6 c4 02 0f 85 08 01 00 00 41 f7 c5 00 02 00 00 74 01 fb 48 8b 44 24 10 <65> 48 2b 05 4d e2 08 12 0f 85 58 01 00 00 48 83 c4 18 5b 41 5c 41
RSP: 0018:ffffc90003117468 EFLAGS: 00000206
RAX: 29a9ab50e382cf00 RBX: ffffffff8e3c45a0 RCX: ffffc90003117474
RDX: 0000000000000001 RSI: ffffffff8da02bce RDI: ffffffff8bf075c0
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000008287e R12: ffffffff816bb704
R13: 0000000000000206 R14: ffff88807de75ac0 R15: 0000000000000002
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:897 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0x3f9/0x20a0 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x160/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x84/0x1a0 mm/page_owner.c:311
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1394 [inline]
__free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:352
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4978 [inline]
slab_alloc_node mm/slub.c:5288 [inline]
__do_kmalloc_node mm/slub.c:5649 [inline]
__kmalloc_node_track_caller_noprof+0x2fd/0x8a0 mm/slub.c:5759
kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:601
__alloc_skb+0x166/0x380 net/core/skbuff.c:670
alloc_skb include/linux/skbuff.h:1383 [inline]
alloc_skb_with_frags+0xe0/0x860 net/core/skbuff.c:6671
sock_alloc_send_pskb+0x7f9/0x980 net/core/sock.c:2965
unix_dgram_sendmsg+0x3e9/0x17f0 net/unix/af_unix.c:2153
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
__sys_sendto+0x4a3/0x520 net/socket.c:2244
__do_sys_sendto net/socket.c:2251 [inline]
__se_sys_sendto net/socket.c:2247 [inline]
__x64_sys_sendto+0xe0/0x1c0 net/socket.c:2247
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f653b785407
RSP: 002b:00007ffcf03da950 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f653b635c80 RCX: 00007f653b785407
RDX: 000000000000005b RSI: 00007ffcf03daa90 RDI: 0000000000000003
RBP: 00007ffcf03daec0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffcf03daed8
R13: 00007ffcf03daa90 R14: 0000000000000040 R15: 00007ffcf03daa90
task:kworker/0:5 state:R running task stack:26232 pid:5886 tgid:5886 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: events_power_efficient gc_worker
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
irqentry_exit+0x36/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:227 [inline]
RIP: 0010:nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:342 [inline]
RIP: 0010:gc_worker+0x2d5/0x16e0 net/netfilter/nf_conntrack_core.c:1548
Code: 00 00 48 c7 c7 48 f1 82 90 e8 97 f2 1b f8 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 45 fa 3f f8 58 48 85 db 0f 85 d4 0f 00 00 c6 fe 3f f8 8b 1d 80 97 06 07 41 89 dc 31 ff 41 83 e4 01 44 89
RSP: 0018:ffffc900044cfb48 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff897c64f9
RDX: ffff88805b6f1e40 RSI: ffffffff897c6508 RDI: 0000000000000007
RBP: ffffffff9af7a9ec R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff88814cc00000
R13: 0000000000040000 R14: dffffc0000000000 R15: 0000000000001770
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
process_scheduled_works kernel/workqueue.c:3346 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
task:syz.2.163 state:R running task stack:25784 pid:6798 tgid:6798 ppid:5837 task_flags:0x20400040 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
irqentry_exit+0x36/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:396 [inline]
RIP: 0010:__rcu_read_unlock+0x30/0x550 kernel/rcu/tree_plugin.h:435
Code: 41 55 41 54 55 65 48 8b 2d a5 b9 fe 11 53 48 8d bd 84 04 00 00 48 b8 00 00 00 00 00 fc ff df 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 4a 02 00 00 65
RSP: 0018:ffffc9000ea0f1d8 EFLAGS: 00000a07
RAX: dffffc0000000000 RBX: ffffc9000ea0f838 RCX: ffffc9000ea0f1cc
RDX: 0000000000000000 RSI: ffffffff8da02bce RDI: ffff88802547df44
RBP: ffff88802547dac0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000037c98 R12: ffffc9000ea0f2c8
R13: ffffc9000ea0f278 R14: ffffc9000ea0f838 R15: ffffc9000ea0f2ac
rcu_read_unlock include/linux/rcupdate.h:899 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0x3fe/0x20a0 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
unpoison_slab_object mm/kasan/common.c:342 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:368
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4978 [inline]
slab_alloc_node mm/slub.c:5288 [inline]
kmem_cache_alloc_noprof+0x250/0x6e0 mm/slub.c:5295
mempool_alloc_noprof+0x179/0x390 mm/mempool.c:406
bio_alloc_bioset+0x47e/0x8d0 block/bio.c:558
bio_alloc include/linux/bio.h:372 [inline]
submit_bh_wbc+0x280/0x740 fs/buffer.c:2804
__block_write_full_folio+0x735/0xe00 fs/buffer.c:1933
block_write_full_folio+0x341/0x400 fs/buffer.c:2753
blkdev_writepages+0xb8/0x140 block/fops.c:491
do_writepages+0x27a/0x600 mm/page-writeback.c:2604
filemap_fdatawrite_wbc mm/filemap.c:389 [inline]
filemap_fdatawrite_wbc+0x104/0x160 mm/filemap.c:379
__filemap_fdatawrite_range+0xb9/0x100 mm/filemap.c:422
filemap_write_and_wait_range mm/filemap.c:694 [inline]
filemap_write_and_wait_range+0xa3/0x130 mm/filemap.c:685
filemap_write_and_wait include/linux/pagemap.h:68 [inline]
sync_blockdev block/bdev.c:260 [inline]
sync_blockdev block/bdev.c:256 [inline]
bdev_release+0x4d3/0x6d0 block/bdev.c:1126
blkdev_release+0x15/0x20 block/fops.c:709
__fput+0x402/0xb70 fs/file_table.c:468
task_work_run+0x150/0x240 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x130 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x426/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2abfb8f6c9
RSP: 002b:00007ffcccca4578 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f2abfde7da0 RCX: 00007f2abfb8f6c9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f2abfde7da0 R08: 000000000002be94 R09: 0000001dccca486f
R10: 00000000003d3f44 R11: 0000000000000246 R12: 0000000000023e75
R13: 00007f2abfde6180 R14: ffffffffffffffff R15: 00007ffcccca4690
rcu: rcu_preempt kthread starved for 10583 jiffies! g17781 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:28024 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 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:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x12/0xc0 kernel/rcu/tree.c:751
Code: 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 53 65 ff 05 43 ee ff 11 e8 2e 39 bc 09 <48> c7 c3 a8 62 a2 93 89 c5 83 f8 07 0f 87 82 00 00 00 48 8d 3c ed
RSP: 0018:ffffc90000a07e68 EFLAGS: 00000286
RAX: 0000000000000001 RBX: ffffffff8e3c45a0 RCX: ffffffff91142786
RDX: 0000000000000000 RSI: ffffffff8bf07540 RDI: ffffffff8bf07580
RBP: 0000000000000000 R08: ffffffff911427aa R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000005d6a R12: ffffffff816bb704
R13: ffffc90000a07f38 R14: ffffc90000a07f6d R15: ffffffff9114278b
FS: 0000000000000000(0000) GS:ffff888124b0d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000560e2d101a38 CR3: 000000006803a000 CR4: 00000000003526f0
Call Trace:
trace_lock_release include/trace/events/lock.h:69 [inline]
lock_release+0x201/0x2f0 kernel/locking/lockdep.c:5879
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:897 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0x3f9/0x20a0 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
unpoison_slab_object mm/kasan/common.c:342 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:368
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4978 [inline]
slab_alloc_node mm/slub.c:5288 [inline]
kmem_cache_alloc_noprof+0x250/0x6e0 mm/slub.c:5295
skb_clone+0x190/0x3f0 net/core/skbuff.c:2050
deliver_clone net/bridge/br_forward.c:125 [inline]
maybe_deliver+0xd4/0x180 net/bridge/br_forward.c:191
br_flood+0x17c/0x650 net/bridge/br_forward.c:238
br_handle_frame_finish+0x1117/0x1f00 net/bridge/br_input.c:229
br_nf_hook_thresh+0x307/0x410 net/bridge/br_netfilter_hooks.c:1167
br_nf_pre_routing_finish_ipv6+0x76a/0xfc0 net/bridge/br_netfilter_ipv6.c:154
NF_HOOK include/linux/netfilter.h:318 [inline]
br_nf_pre_routing_ipv6+0x3cd/0x8c0 net/bridge/br_netfilter_ipv6.c:184
br_nf_pre_routing+0x860/0x15b0 net/bridge/br_netfilter_hooks.c:508
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
br_handle_frame+0xb28/0x14e0 net/bridge/br_input.c:442
__netif_receive_skb_core.constprop.0+0xa25/0x4bd0 net/core/dev.c:5966
__netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6077
__netif_receive_skb+0x1d/0x160 net/core/dev.c:6192
process_backlog+0x439/0x15e0 net/core/dev.c:6544
__napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7594
napi_poll net/core/dev.c:7657 [inline]
net_rx_action+0x97f/0xef0 net/core/dev.c:7784
handle_softirqs+0x219/0x8e0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x109/0x170 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+0xa4/0xc0 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+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 97 6f 02 c3 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 83 b3 2c 00 fb f4 3c 0a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197de8 EFLAGS: 000002c6
RAX: 0000000000e10287 RBX: 0000000000000001 RCX: ffffffff8b5d72a9
RDX: 0000000000000000 RSI: ffffffff8da28539 RDI: ffffffff8bf075c0
RBP: ffffed1003a5bb58 R08: 0000000000000001 R09: ffffed10170a6655
R10: ffff8880b85332ab R11: 0000000000000001 R12: 0000000000000001
R13: ffff88801d2ddac0 R14: ffffffff908244d0 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x38d/0x500 kernel/sched/idle.c:330
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x148