rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P1419/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=259341, q=776 ncpus=1)
task:syz.3.13365 state:R running task stack:27144 pid:1419 tgid:1419 ppid:5728 task_flags:0x40004c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556
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+0x205/0xa00 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__orc_find+0x60/0xf0 arch/x86/kernel/unwind_orc.c:101
Code: 89 ff 48 89 fd eb 0c 48 8d 6b 04 49 89 df 49 39 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
RSP: 0018:ffffc9000650f370 EFLAGS: 00000203
RAX: ffffffff91c52eb2 RBX: ffffffff913c2470 RCX: dffffc0000000000
RDX: 0000000000000002 RSI: 0000000000000005 RDI: ffffffff913c2458
RBP: ffffffff913c2474 R08: ffffffff91c52f00 R09: 0000000000000007
R10: 0000000000000200 R11: 000000000000c5cf R12: ffffffff913c2488
R13: ffffffff81c5cfc6 R14: ffffffff913c2458 R15: ffffffff913c2470
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:165
__reset_page_owner+0x84/0x190 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1406 [inline]
free_unref_folios+0xa44/0x1710 mm/page_alloc.c:3011
folios_put_refs+0x585/0xaa0 mm/swap.c:1057
free_pages_and_swap_cache+0x30b/0x3b0 mm/swap_state.c:589
__tlb_batch_free_encoded_pages+0xe9/0x280 mm/mmu_gather.c:138
tlb_batch_pages_flush mm/mmu_gather.c:151 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:417 [inline]
tlb_flush_mmu mm/mmu_gather.c:424 [inline]
tlb_finish_mmu+0x1b0/0x810 mm/mmu_gather.c:549
exit_mmap+0x454/0xa00 mm/mmap.c:1313
__mmput+0x12a/0x410 kernel/fork.c:1187
mmput+0x67/0x80 kernel/fork.c:1210
exit_mm kernel/exit.c:615 [inline]
do_exit+0x8b1/0x2ae0 kernel/exit.c:997
do_group_exit+0xd5/0x2a0 kernel/exit.c:1152
__do_sys_exit_group kernel/exit.c:1163 [inline]
__se_sys_exit_group kernel/exit.c:1161 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1161
x64_sys_call+0x102c/0x1530 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f489bf9e019
RSP: 002b:00007ffe7b25cb98 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f489bf9e019
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffe7b25cbfc R08: 0000000000000000 R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000d32
R13: 00000000000927c0 R14: 00000000000ba3e3 R15: 00007ffe7b25cc50
rcu: rcu_preempt kthread starved for 8257 jiffies! g259341 f0x0 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:27592 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7326
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 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: 3232 Comm: kworker/R-bat_e Tainted: G U L syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: bat_events batadv_dat_purge
RIP: 0010:rol32 include/linux/bitops.h:126 [inline]
RIP: 0010:jhash2 include/linux/jhash.h:129 [inline]
RIP: 0010:hash_stack lib/stackdepot.c:571 [inline]
RIP: 0010:stack_depot_save_flags+0xcb/0x9d0 lib/stackdepot.c:672
Code: 01 44 89 c1 44 29 c0 45 01 c8 c1 c1 08 31 c8 44 89 c9 41 89 c1 29 c1 44 01 c0 41 c1 c1 10 41 31 c9 44 89 c9 45 29 c8 41 01 c1 c9 0d 41 31 c8 44 29 c0 89 c1 44 89 c0 45 01 c8 c1 c0 04 31 c8
RSP: 0018:ffffc90000007340 EFLAGS: 00000a13
RAX: 00000000c9dcaa9e RBX: 0000000000000001 RCX: 0000000083209f6f
RDX: 0000000000000018 RSI: ffffc9000000744c RDI: 0000000000000003
RBP: 0000000000000820 R08: 000000008640f057 R09: 000000004cfd4a0d
R10: 0000000000000200 R11: 000000000000756b R12: ffffc90000007398
R13: 0000000000000018 R14: ffff88816ed70140 R15: ffff8880b8443cf0
FS: 0000000000000000(0000) GS:ffff888123de1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f291bd56a80 CR3: 0000000076954000 CR4: 00000000003526f0
Call Trace:
kasan_save_stack+0x3f/0x50 mm/kasan/common.c:58
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4584 [inline]
slab_alloc_node mm/slub.c:4917 [inline]
kmem_cache_alloc_noprof+0x26b/0x6a0 mm/slub.c:4931
skb_clone+0x190/0x400 net/core/skbuff.c:2116
deliver_clone net/bridge/br_forward.c:125 [inline]
br_flood+0x34f/0x7b0 net/bridge/br_forward.c:257
br_handle_frame_finish+0x1014/0x1fa0 net/bridge/br_input.c:229
nf_hook_bridge_pre net/bridge/br_input.c:313 [inline]
br_handle_frame+0x97f/0x1540 net/bridge/br_input.c:442
__netif_receive_skb_core.constprop.0+0x6c5/0x3530 net/core/dev.c:6099
__netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6210
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6325
process_backlog+0x37a/0x1580 net/core/dev.c:6676
__napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7735
napi_poll net/core/dev.c:7798 [inline]
net_rx_action+0xa40/0xf20 net/core/dev.c:7955
handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622
do_softirq kernel/softirq.c:523 [inline]
do_softirq+0xac/0xe0 kernel/softirq.c:510
__local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450
spin_unlock_bh include/linux/spinlock.h:396 [inline]
__batadv_dat_purge.part.0+0x294/0x3c0 net/batman-adv/distributed-arp-table.c:186
__batadv_dat_purge net/batman-adv/distributed-arp-table.c:167 [inline]
batadv_dat_purge+0x4b/0xa0 net/batman-adv/distributed-arp-table.c:205
process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
process_scheduled_works kernel/workqueue.c:3405 [inline]
rescuer_thread+0x905/0x14a0 kernel/workqueue.c:3629
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245