rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4966/1:b..l P13656/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=138697, q=1984 ncpus=1)
task:syz-executor state:R running task stack:23960 pid:13656 tgid:13656 ppid:13602 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7284
preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:7606
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+0x205/0xa10 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:81 [inline]
RIP: 0010:__orc_find+0x70/0xf0 arch/x86/kernel/unwind_orc.c:103
Code: ec 72 4e 4c 89 e2 48 29 ea 48 89 d6 48 c1 ea 3f 48 c1 fe 02 48 01 f2 48 d1 fa 48 8d 5c 95 00 48 89 da 48 c1 ea 03 0f b6 34 0a <48> 89 da 83 e2 07 83 c2 03 40 38 f2 7c 05 40 84 f6 75 4b 48 63 13
RSP: 0018:ffffc900038772c0 EFLAGS: 00000a03
RAX: ffffffff92ed5c48 RBX: ffffffff9261abfc RCX: dffffc0000000000
RDX: 1ffffffff24c357f RSI: 0000000000000000 RDI: ffffffff9261abdc
RBP: ffffffff9261abdc R08: ffffffff92ed5cb4 R09: 0000000000000007
R10: 0000000000000200 R11: 000000000000f623 R12: ffffffff9261ac20
R13: ffffffff81f6236d R14: ffffffff9261abdc R15: ffffffff9261abdc
orc_find arch/x86/kernel/unwind_orc.c:238 [inline]
unwind_next_frame+0x2ec/0x2090 arch/x86/kernel/unwind_orc.c:510
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x162/0x1e0 mm/page_owner.c:183
__reset_page_owner+0x84/0x190 mm/page_owner.c:338
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1418 [inline]
free_unref_folios+0xa4a/0x1790 mm/page_alloc.c:3022
folios_put_refs+0x585/0xaa0 mm/folio.c:1036
folio_batch_release include/linux/folio_batch.h:101 [inline]
shmem_undo_range+0x5e5/0x1570 mm/shmem.c:1161
shmem_truncate_range mm/shmem.c:1289 [inline]
shmem_evict_inode+0x3b1/0xca0 mm/shmem.c:1420
evict+0x3c2/0xad0 fs/inode.c:822
iput_final fs/inode.c:2014 [inline]
iput.part.0+0x989/0x1050 fs/inode.c:2063
iput+0x35/0x40 fs/inode.c:2029
filename_unlinkat+0x466/0x730 fs/namei.c:5752
__do_sys_unlink fs/namei.c:5783 [inline]
__se_sys_unlink fs/namei.c:5780 [inline]
__x64_sys_unlink+0x46/0x70 fs/namei.c:5780
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7b5f79d647
RSP: 002b:00007ffd3ba663b8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7b5f79d647
RDX: 00007ffd3ba663e0 RSI: 00007ffd3ba66470 RDI: 00007ffd3ba66470
RBP: 00007ffd3ba66470 R08: 00007ffd3ba67470 R09: 00000000ffffffff
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffd3ba67500
R13: 00007f7b5f834cf3 R14: 00000000000f3687 R15: 00007ffd3ba67540
task:udevd state:R running task stack:24776 pid:4966 tgid:4966 ppid:1 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7284
preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:7606
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+0x205/0xa10 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_release+0x19e/0x310 kernel/locking/lockdep.c:5968
Code: ff 65 0f c1 05 5b 5e a6 13 83 f8 01 0f 85 27 01 00 00 9c 58 f6 c4 02 0f 85 12 01 00 00 41 f7 c6 00 02 00 00 0f 85 c8 00 00 00 <48> 8b 44 24 10 65 48 2b 05 5d 17 a6 13 0f 85 4d 01 00 00 48 83 c4
RSP: 0018:ffffc90003697860 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8fdec5e0 RCX: ffffc9000369786c
RDX: 0000000000000000 RSI: ffffffff8e3bd2c3 RDI: ffffffff8c625580
RBP: ffffffff81b9c54e R08: ffffffff92de86fa R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000001 R12: ffff88807d252580
R13: ffffc90003697918 R14: 0000000000000202 R15: 0000000000000002
rcu_lock_release include/linux/rcupdate.h:319 [inline]
rcu_read_unlock include/linux/rcupdate.h:880 [inline]
class_rcu_destructor include/linux/rcupdate.h:1216 [inline]
unwind_next_frame+0x3c3/0x2090 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x162/0x1e0 mm/page_owner.c:183
__reset_page_owner+0x84/0x190 mm/page_owner.c:338
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1418 [inline]
__free_frozen_pages+0x79f/0x10f0 mm/page_alloc.c:2962
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:361
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4683 [inline]
slab_alloc_node mm/slub.c:4996 [inline]
kmem_cache_alloc_noprof+0x269/0x6a0 mm/slub.c:5010
alloc_filename fs/namei.c:147 [inline]
do_getname+0x35/0x390 fs/namei.c:187
getname include/linux/fs.h:2560 [inline]
getname_maybe_null include/linux/fs.h:2567 [inline]
class_filename_maybe_null_constructor include/linux/fs.h:2591 [inline]
vfs_fstatat+0xd0/0xe0 fs/stat.c:368
__do_sys_newfstatat+0x9d/0x120 fs/stat.c:538
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd5acf11b0a
RSP: 002b:00007fff3e90af88 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 000056032b55d428 RCX: 00007fd5acf11b0a
RDX: 00007fff3e90af90 RSI: 000056032b54bed3 RDI: 00000000ffffff9c
RBP: 00005603693cd668 R08: 00063478c1c69200 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff3e90af90 R14: 0000000000000000 R15: 00063478c1c69200
rcu: rcu_preempt kthread starved for 1030 jiffies! g138697 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27560 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7284
__schedule_loop kernel/sched/core.c:7361 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7376
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x8f0 kernel/rcu/tree.c:2122
rcu_gp_kthread+0x17a/0x220 kernel/rcu/tree.c:2330
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 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: 3219 Comm: kworker/R-bat_e Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Workqueue: bat_events batadv_dat_purge
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:422 [inline]
RIP: 0010:unwind_next_frame+0xd26/0x2090 arch/x86/kernel/unwind_orc.c:614
Code: ff 48 8b 7c 24 28 e8 f9 ea ff ff 48 89 ee 48 8b 4c 24 20 48 ba 00 00 00 00 00 fc ff df 48 c1 ee 03 4c 8b 44 24 18 80 3c 16 00 <0f> 85 b2 0f 00 00 48 8b 14 24 49 89 45 48 48 b8 00 00 00 00 00 fc
RSP: 0018:ffffc90000006ff8 EFLAGS: 00000246
RAX: ffffffff8a09397f RBX: 0000000000000002 RCX: ffffffff9383d3c4
RDX: dffffc0000000000 RSI: 1ffff92000000e16 RDI: ffffc90000007600
RBP: ffffc900000070b0 R08: ffffffff9383d3c8 R09: 0000000000000007
R10: 0000000000000200 R11: 000000000008f9a4 R12: ffffc900000070b8
R13: ffffc90000007068 R14: ffffc90000007608 R15: ffffc9000000709c
FS: 0000000000000000(0000) GS:ffff888122946000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6c5e75da08 CR3: 000000004deed000 CR4: 00000000003526f0
Call Trace:
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
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:351 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:377
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4683 [inline]
slab_alloc_node mm/slub.c:4996 [inline]
kmem_cache_alloc_node_noprof+0x282/0x6e0 mm/slub.c:5068
kmalloc_reserve+0x148/0x350 net/core/skbuff.c:615
__alloc_skb+0x185/0x710 net/core/skbuff.c:715
alloc_skb include/linux/skbuff.h:1384 [inline]
synproxy_send_client_synack_ipv6+0x19f/0x7a0 net/netfilter/nf_synproxy_core.c:883
nft_synproxy_eval_v6 net/netfilter/nft_synproxy.c:90 [inline]
nft_synproxy_do_eval+0x95f/0xd30 net/netfilter/nft_synproxy.c:146
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x2e5/0x19d0 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0xf3/0x400 net/netfilter/nft_chain_filter.c:162
nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline]
nf_hook_slow+0xbf/0x220 net/netfilter/core.c:619
nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:280
NF_HOOK include/linux/netfilter.h:323 [inline]
ip6_input+0xe0/0x2f0 net/ipv6/ip6_input.c:545
dst_input include/net/dst.h:481 [inline]
ip6_rcv_finish net/ipv6/ip6_input.c:119 [inline]
NF_HOOK include/linux/netfilter.h:325 [inline]
NF_HOOK include/linux/netfilter.h:319 [inline]
ipv6_rcv+0x263/0x3d0 net/ipv6/ip6_input.c:351
__netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:6297
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6410
process_backlog+0x487/0x1600 net/core/dev.c:6761
__napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0xa40/0xf20 net/core/dev.c:8050
handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645
do_softirq kernel/softirq.c:546 [inline]
do_softirq+0xaf/0xf0 kernel/softirq.c:533
__local_bh_enable_ip+0xff/0x120 kernel/softirq.c:473
spin_unlock_bh include/linux/spinlock.h:407 [inline]
__batadv_dat_purge.part.0+0x294/0x3c0 net/batman-adv/distributed-arp-table.c:252
__batadv_dat_purge net/batman-adv/distributed-arp-table.c:233 [inline]
batadv_dat_purge+0x4b/0xa0 net/batman-adv/distributed-arp-table.c:271
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
process_scheduled_works kernel/workqueue.c:3479 [inline]
rescuer_thread+0x918/0x14e0 kernel/workqueue.c:3703
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245