rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6064/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=13141, q=1772 ncpus=2)
task:syz.2.32 state:R running task stack:26728 pid:6064 tgid:6049 ppid:5838 task_flags:0x400140 flags:0x00080003
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:unwind_next_frame+0x1617/0x20a0 arch/x86/kernel/unwind_orc.c:665
Code: 80 3c 02 00 0f 84 cb f9 ff ff e8 14 0f b9 00 e9 c1 f9 ff ff 48 b8 00 00 00 00 00 fc ff df 48 8b 14 24 48 c1 ea 03 80 3c 02 00 <0f> 85 56 05 00 00 49 8d 7d 08 49 8b 5d 38 48 b8 00 00 00 00 00 fc
RSP: 0018:ffffc9000af86ef0 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffc9000af88000
RDX: 1ffff920015f0df3 RSI: ffffc9000af87ee8 RDI: ffffc9000af86fa0
RBP: ffffc9000af87f38 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000005fa7 R12: ffffc9000af86fb0
R13: ffffc9000af86f60 R14: ffffc9000af87f18 R15: ffffc9000af86f94
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_unref_folios+0xa31/0x1610 mm/page_alloc.c:2958
folios_put_refs+0x4be/0x750 mm/swap.c:1002
free_pages_and_swap_cache+0x245/0x4a0 mm/swap_state.c:355
__tlb_batch_free_encoded_pages+0xf9/0x290 mm/mmu_gather.c:136
tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
tlb_flush_mmu mm/mmu_gather.c:404 [inline]
tlb_finish_mmu+0x168/0x7c0 mm/mmu_gather.c:497
vms_clear_ptes+0x55e/0x770 mm/vma.c:1235
vms_clean_up_area mm/vma.c:1247 [inline]
__mmap_prepare mm/vma.c:2396 [inline]
__mmap_region+0x5df/0x27a0 mm/vma.c:2652
mmap_region+0x1ab/0x3f0 mm/vma.c:2740
do_mmap+0xa3e/0x1210 mm/mmap.c:558
vm_mmap_pgoff+0x29e/0x470 mm/util.c:581
ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:604
__do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
__se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
__x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
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: 0033:0x7fb3c958f7c9
RSP: 002b:00007fb3ca37c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fb3c97e6180 RCX: 00007fb3c958f7c9
RDX: 00000000000000df RSI: 0000000000400008 RDI: 0000000000000000
RBP: 00007fb3c9613f91 R08: 0000000000000002 R09: 0000000000008000
R10: 0000000000009b72 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb3c97e6218 R14: 00007fb3c97e6180 R15: 00007fff08725908
rcu: rcu_preempt kthread starved for 6534 jiffies! g13141 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:28552 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 10/25/2025
RIP: 0010:lock_release+0x6/0x2f0 kernel/locking/lockdep.c:5876
Code: 44 24 1c 44 8b 4c 24 18 4c 8b 54 24 10 44 8b 5c 24 0c eb 8c 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 41 55 41 54 49 89 f4 53 48 89 fb 48 83 ec 18 65 48 8b 05 69
RSP: 0018:ffffc90000a07da8 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffc90000a08f28 RCX: ffffc90000a09001
RDX: 0000000000000000 RSI: ffffffff816bb704 RDI: ffffffff8e3c3ea0
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000083484 R12: ffffc90000a07e78
R13: ffffc90000a07e28 R14: ffffc90000a08f28 R15: ffffc90000a07e5c
FS: 0000000000000000(0000) GS:ffff888124afe000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558cd07d0088 CR3: 0000000029702000 CR4: 00000000003526f0
Call Trace:
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_node_noprof+0x28a/0x770 mm/slub.c:5340
kmalloc_reserve+0x18b/0x2c0 net/core/skbuff.c:579
__alloc_skb+0x166/0x380 net/core/skbuff.c:670
alloc_skb include/linux/skbuff.h:1383 [inline]
nlmsg_new include/net/netlink.h:1055 [inline]
fdb_notify+0xa4/0x1a0 net/bridge/br_fdb.c:188
br_fdb_update+0x323/0x7c0 net/bridge/br_fdb.c:1036
br_handle_frame_finish+0xdf1/0x1f00 net/bridge/br_input.c:144
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: 07 6d 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 23 f4 29 00 fb f4 7c 09 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: 00000000007c0649 RBX: 0000000000000001 RCX: ffffffff8b6032a9
RDX: 0000000000000000 RSI: ffffffff8da2bee9 RDI: ffffffff8bf08840
RBP: ffffed1003a5bb58 R08: 0000000000000001 R09: ffffed10170a6655
R10: ffff8880b85332ab R11: 0000000000000001 R12: 0000000000000001
R13: ffff88801d2ddac0 R14: ffffffff90826cd0 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