rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4977/1:b..l P5623/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=23905, q=1107 ncpus=2)
task:syz-executor state:R running task stack:23032 pid:5623 tgid:5623 ppid:1 task_flags:0x40054c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7409
preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:190
spin_unlock include/linux/spinlock.h:390 [inline]
zap_pte_range mm/memory.c:1964 [inline]
zap_pmd_range mm/memory.c:2020 [inline]
zap_pud_range mm/memory.c:2048 [inline]
zap_p4d_range mm/memory.c:2069 [inline]
__zap_vma_range+0x3e40/0x4c70 mm/memory.c:2109
unmap_vmas+0x390/0x550 mm/memory.c:2178
exit_mmap+0x293/0x9f0 mm/mmap.c:1300
__mmput+0x118/0x420 kernel/fork.c:1181
exit_mm+0x221/0x2d0 kernel/exit.c:610
do_exit+0x6cd/0x2360 kernel/exit.c:992
do_group_exit+0x22d/0x2f0 kernel/exit.c:1147
get_signal+0x121b/0x12c0 kernel/signal.c:3038
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9217b5d68e
RSP: 002b:00007ffe6bcfa848 EFLAGS: 00000246 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 000055555e0ca500 RCX: 00007f9217b5d68e
RDX: 0000000040000000 RSI: 00007ffe6bcfa8ec RDI: ffffffffffffffff
RBP: 00007ffe6bcfa8ec R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000009b
R13: 000055555e0dda00 R14: 00000000000204a9 R15: 00007ffe6bcfa940
task:klogd state:R running task stack:24728 pid:4977 tgid:4977 ppid:1 task_flags:0x400100 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7552
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:deref_stack_reg+0x0/0x220 arch/x86/kernel/unwind_orc.c:418
Code: ff ff 48 89 4c 24 18 e8 2e 81 ba 00 48 8b 4c 24 18 e9 f2 fe ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 41 57 41 56 41 55 41 54 53 48 83 ec 10 48 89 d3 49 89 f0 49 89
RSP: 0018:ffffc90002e27338 EFLAGS: 00000283
RAX: fffffffffffffff0 RBX: ffffffff90d46cc2 RCX: 0000000000000000
RDX: ffffc90002e27428 RSI: ffffc90002e27698 RDI: ffffc90002e273e8
RBP: 1ffffffff21a8d98 R08: ffffc90002e27698 R09: 0000000000000000
R10: ffffc90002e27438 R11: fffff520005c4e89 R12: dffffc0000000000
R13: ffffffff90d46cc3 R14: ffffc90002e273e8 R15: ffffc90002e27430
unwind_next_frame+0x19bd/0x2550 arch/x86/kernel/unwind_orc.c:-1
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1397 [inline]
__free_frozen_pages+0xc0d/0xd20 mm/page_alloc.c:2938
__slab_free+0x274/0x2c0 mm/slub.c:5672
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4610 [inline]
slab_alloc_node mm/slub.c:4939 [inline]
__do_kmalloc_node mm/slub.c:5333 [inline]
__kmalloc_node_track_caller_noprof+0x48f/0x7b0 mm/slub.c:5438
kmalloc_reserve net/core/skbuff.c:637 [inline]
__alloc_skb+0x2bd/0x7a0 net/core/skbuff.c:715
alloc_skb include/linux/skbuff.h:1386 [inline]
alloc_skb_with_frags+0xc6/0x760 net/core/skbuff.c:6769
sock_alloc_send_pskb+0x878/0x990 net/core/sock.c:3010
unix_dgram_sendmsg+0x4da/0x17b0 net/unix/af_unix.c:2136
sock_sendmsg_nosec net/socket.c:775 [inline]
__sock_sendmsg net/socket.c:790 [inline]
__sys_sendto+0x626/0x6c0 net/socket.c:2252
__do_sys_sendto net/socket.c:2259 [inline]
__se_sys_sendto net/socket.c:2255 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2255
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9566e2b407
RSP: 002b:00007ffc18081cc0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f9566cdbc80 RCX: 00007f9566e2b407
RDX: 00000000000000a0 RSI: 00007ffc18081e00 RDI: 0000000000000003
RBP: 00007ffc18082230 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffc18082248
R13: 00007ffc18081e00 R14: 0000000000000085 R15: 00007ffc18081e00
rcu: rcu_preempt kthread starved for 9230 jiffies! g23905 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:28152 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7322
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 3229 Comm: kworker/R-bat_e Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: bat_events batadv_dat_purge
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:56 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:409 [inline]
RIP: 0010:deref_stack_reg+0x5a/0x220 arch/x86/kernel/unwind_orc.c:419
Code: 00 4c 89 04 24 74 13 e8 04 81 ba 00 4c 8b 04 24 48 be 00 00 00 00 00 fc ff df 48 89 5c 24 08 49 8b 6f 08 49 8d 7f 10 49 89 fd <49> c1 ed 03 41 80 7c 35 00 00 74 13 e8 d5 80 ba 00 4c 8b 04 24 48
RSP: 0018:ffffc90000006dd8 EFLAGS: 00000246
RAX: fffffffffffffff0 RBX: ffffc90000006f08 RCX: 0000000000000000
RDX: ffffc90000006f08 RSI: dffffc0000000000 RDI: ffffc90000006ed8
RBP: ffffc90000000000 R08: ffffc90000007740 R09: 0000000000000000
R10: ffffc90000006f18 R11: fffff52000000de5 R12: 1ffff92000000dda
R13: ffffc90000006ed8 R14: ffffc90000006ec8 R15: ffffc90000006ec8
FS: 0000000000000000(0000) GS:ffff88812527b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fda49200218 CR3: 000000003404a000 CR4: 00000000003526f0
Call Trace:
unwind_next_frame+0x19bd/0x2550 arch/x86/kernel/unwind_orc.c:-1
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4610 [inline]
slab_alloc_node mm/slub.c:4939 [inline]
kmem_cache_alloc_node_noprof+0x380/0x680 mm/slub.c:4991
__alloc_skb+0x1d7/0x7a0 net/core/skbuff.c:704
alloc_skb include/linux/skbuff.h:1386 [inline]
nlmsg_new include/net/netlink.h:1055 [inline]
fdb_notify+0xa6/0x160 net/bridge/br_fdb.c:188
br_fdb_update+0x4e6/0x6c0 net/bridge/br_fdb.c:1024
br_handle_frame_finish+0x618/0x1990 net/bridge/br_input.c:144
br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1
br_nf_pre_routing_finish_ipv6+0x90c/0xc40 net/bridge/br_netfilter_ipv6.c:-1
NF_HOOK include/linux/netfilter.h:318 [inline]
br_nf_pre_routing_ipv6+0x382/0x6f0 net/bridge/br_netfilter_ipv6.c:183
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
br_handle_frame+0x127f/0x1510 net/bridge/br_input.c:442
__netif_receive_skb_core+0x989/0x30b0 net/core/dev.c:6093
__netif_receive_skb_one_core net/core/dev.c:6204 [inline]
__netif_receive_skb net/core/dev.c:6319 [inline]
process_backlog+0x706/0x1860 net/core/dev.c:6670
__napi_poll+0xaa/0x330 net/core/dev.c:7729
napi_poll net/core/dev.c:7792 [inline]
net_rx_action+0x61d/0xf50 net/core/dev.c:7949
handle_softirqs+0x225/0x840 kernel/softirq.c:622
do_softirq+0x76/0xd0 kernel/softirq.c:523
__local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
spin_unlock_bh include/linux/spinlock.h:396 [inline]
__batadv_dat_purge net/batman-adv/distributed-arp-table.c:186 [inline]
batadv_dat_purge+0x2d7/0x3c0 net/batman-adv/distributed-arp-table.c:205
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3397
rescuer_thread+0x7b6/0x10b0 kernel/workqueue.c:3621
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
net_ratelimit: 3886 callbacks suppressed
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
net_ratelimit: 3720 callbacks suppressed
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)