rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8246/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=33369, q=274 ncpus=2)
task:syz.3.670 state:R running task stack:24264 pid:8246 tgid:8244 ppid:5849 task_flags:0x2040044c flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5392 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6781
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7104
irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:87 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x9f/0x2c0 mm/kasan/generic.c:189
Code: 00 fc ff df 4d 8d 34 19 4d 89 f4 4d 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 41 01 00 00 4c 89 cb 48 f7 d3 4c 01 fb 41 80 3b 00 <0f> 85 de 01 00 00 49 ff c3 48 ff c3 75 ee e9 21 01 00 00 44 89 dd
RSP: 0018:ffffc90003b0ecc0 EFLAGS: 00000246
RAX: 1ffff92000761d01 RBX: fffffffffffffffe RCX: ffffffff81728458
RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc90003b0ee38
RBP: 0000000000000000 R08: ffffc90003b0ee47 R09: 1ffff92000761dc8
R10: dffffc0000000000 R11: fffff52000761dc7 R12: 0000000000000002
R13: ffffc90003b0ee38 R14: fffff52000761dc9 R15: 1ffff92000761dc7
__asan_memset+0x22/0x50 mm/kasan/shadow.c:84
unwind_next_frame+0xc98/0x2390 arch/x86/kernel/unwind_orc.c:592
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1254 [inline]
__free_frozen_pages+0xc6e/0xe50 mm/page_alloc.c:2717
discard_slab mm/slub.c:2716 [inline]
__put_partials+0x161/0x1c0 mm/slub.c:3185
put_cpu_partial+0x17c/0x250 mm/slub.c:3260
__slab_free+0x2f7/0x400 mm/slub.c:4512
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4147 [inline]
slab_alloc_node mm/slub.c:4196 [inline]
kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4203
alloc_buffer_head+0x2a/0x270 fs/buffer.c:3032
folio_alloc_buffers+0x32d/0x640 fs/buffer.c:935
create_empty_buffers+0x3a/0x530 fs/buffer.c:1697
__block_write_full_folio+0xc5/0xe10 fs/buffer.c:1853
blkdev_writepages+0xd1/0x170 block/fops.c:483
do_writepages+0x32e/0x550 mm/page-writeback.c:2635
filemap_fdatawrite_wbc mm/filemap.c:386 [inline]
__filemap_fdatawrite_range mm/filemap.c:419 [inline]
filemap_write_and_wait_range+0x217/0x310 mm/filemap.c:691
filemap_write_and_wait include/linux/pagemap.h:68 [inline]
sync_blockdev block/bdev.c:260 [inline]
bdev_release+0x192/0x650 block/bdev.c:1126
blkdev_release+0x15/0x20 block/fops.c:684
__fput+0x449/0xa70 fs/file_table.c:465
task_work_run+0x1d1/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x8d1/0x2550 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 kernel/exit.c:1108
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f633c98e969
RSP: 002b:00007f633d869038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007f633cbb6080 RCX: 00007f633c98e969
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f633ca10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f633cbb6080 R15: 00007f633ccdfa28
rcu: rcu_preempt kthread starved for 9235 jiffies! g33369 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:27320 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5392 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6781
__schedule_loop kernel/sched/core.c:6859 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6874
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
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 6.15.0-syzkaller-08486-gf66bc387efbe #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:unwind_next_frame+0x131/0x2390 arch/x86/kernel/unwind_orc.c:482
Code: 2b 00 4c 89 6c 24 70 48 89 5c 24 68 4d 8d 6e 50 4c 89 e8 48 c1 e8 03 48 89 44 24 38 80 3c 28 00 74 08 4c 89 ef e8 0f f0 b0 00 <49> 8b 5d 00 48 85 db 74 23 48 81 c3 88 00 00 00 48 89 d8 48 c1 e8
RSP: 0018:ffffc90000a073b8 EFLAGS: 00000246
RAX: 1ffff92000140e9b RBX: ffffffff8218b34f RCX: a823f50d0127d500
RDX: 0000000000000000 RSI: ffffffff8be264a0 RDI: ffffffff8be26460
RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffffff81727865
R10: ffffc90000a074d8 R11: ffffffff81acdbe0 R12: 1ffff92000140e91
R13: ffffc90000a074d8 R14: ffffc90000a07488 R15: ffffffff81727865
FS: 0000000000000000(0000) GS:ffff888125d63000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000404030 CR3: 000000005fe50000 CR4: 00000000003526f0
DR0: 0000000000000680 DR1: 0000000000000003 DR2: 0000000000000007
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
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:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2380 [inline]
slab_free mm/slub.c:4642 [inline]
kmem_cache_free+0x18f/0x400 mm/slub.c:4744
skb_ext_del include/linux/skbuff.h:4892 [inline]
nf_bridge_info_free net/bridge/br_netfilter_hooks.c:156 [inline]
br_nf_dev_queue_xmit+0x4fe/0x2680 net/bridge/br_netfilter_hooks.c:854
NF_HOOK+0x618/0x6b0 include/linux/netfilter.h:317
br_nf_post_routing+0xb66/0xfe0 net/bridge/br_netfilter_hooks.c:969
nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline]
nf_hook_slow+0xc2/0x220 net/netfilter/core.c:623
nf_hook include/linux/netfilter.h:272 [inline]
NF_HOOK+0x215/0x3c0 include/linux/netfilter.h:315
br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66
br_nf_hook_thresh net/bridge/br_netfilter_hooks.c:-1 [inline]
br_nf_forward_finish+0xa40/0xe60 net/bridge/br_netfilter_hooks.c:665
NF_HOOK+0x618/0x6b0 include/linux/netfilter.h:317
br_nf_forward_ip+0x647/0x7e0 net/bridge/br_netfilter_hooks.c:719
nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline]
nf_hook_slow+0xc2/0x220 net/netfilter/core.c:623
nf_hook include/linux/netfilter.h:272 [inline]
NF_HOOK+0x215/0x3c0 include/linux/netfilter.h:315
__br_forward+0x41e/0x600 net/bridge/br_forward.c:115
br_handle_frame_finish+0x14b4/0x19b0 net/bridge/br_input.c:221
br_nf_hook_thresh+0x3c3/0x4a0 net/bridge/br_netfilter_hooks.c:-1
br_nf_pre_routing_finish_ipv6+0x948/0xd00 net/bridge/br_netfilter_ipv6.c:-1
NF_HOOK include/linux/netfilter.h:317 [inline]
br_nf_pre_routing_ipv6+0x37e/0x6b0 net/bridge/br_netfilter_ipv6.c:184
nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:283 [inline]
br_handle_frame+0x982/0x14c0 net/bridge/br_input.c:434
__netif_receive_skb_core+0x10de/0x4180 net/core/dev.c:5863
__netif_receive_skb_one_core net/core/dev.c:5975 [inline]
__netif_receive_skb+0x72/0x380 net/core/dev.c:6090
process_backlog+0x60e/0x14f0 net/core/dev.c:6442
__napi_poll+0xc7/0x480 net/core/dev.c:7414
napi_poll net/core/dev.c:7478 [inline]
net_rx_action+0x707/0xe30 net/core/dev.c:7605
handle_softirqs+0x286/0x870 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
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:82
Code: 43 d5 02 00 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 c3 32 24 00 f3 0f 1e fa fb f4 18 d5 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: a823f50d0127d500 RBX: ffffffff81975388 RCX: a823f50d0127d500
RDX: 0000000000000001 RSI: ffffffff8d96e954 RDI: ffffffff8be264c0
RBP: ffffc90000197f20 R08: ffff8880b8732f5b R09: 1ffff110170e65eb
R10: dffffc0000000000 R11: ffffed10170e65ec R12: ffffffff8fa0a2f0
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003a58b40
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:743
default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
cpuidle_idle_call kernel/sched/idle.c:185 [inline]
do_idle+0x1e8/0x510 kernel/sched/idle.c:325
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x147