rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...0: (2 ticks this GP) idle=e374/0/0x1 softirq=54939/54939 fqs=1294
rcu: hardirqs softirqs csw/system
rcu: number: 0 0 0
rcu: cputime: 0 0 0 ==> 52500(ms)
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12294/1:b..l P5477/1:b..l P12290/1:b..l
rcu: (detected by 1, t=10505 jiffies, g=61153, q=422 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:mark_lock+0x17/0xa20 kernel/locking/lockdep.c:4714
Code: 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 41 57 41 56 41 55 49 89 fd 41 54 49 89 f4 53 48 83 e4 f0 <48> 83 ec 70 65 48 8b 1d d5 f4 2d 12 48 89 5c 24 68 89 d3 83 fa 08
RSP: 0018:ffffc90000007c00 EFLAGS: 00000086
RAX: 000000000000000c RBX: ffffffff8e496178 RCX: 0000000000000001
RDX: 0000000000000008 RSI: ffffffff8e496178 RDI: ffffffff8e4955c0
RBP: ffffc90000007c30 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff8e496178
R13: ffffffff8e4955c0 R14: 0000000000000001 R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffff8881242ef000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000001a9030 CR3: 000000002623f000 CR4: 00000000003526f0
Call Trace:
mark_usage kernel/locking/lockdep.c:4674 [inline]
__lock_acquire+0x4a5/0x2630 kernel/locking/lockdep.c:5191
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b1/0x370 kernel/locking/lockdep.c:5825
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
_raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:166
debug_object_deactivate+0x135/0x3b0 lib/debugobjects.c:890
debug_hrtimer_deactivate kernel/time/hrtimer.c:490 [inline]
__run_hrtimer kernel/time/hrtimer.c:1898 [inline]
__hrtimer_run_queues+0x2f0/0xa00 kernel/time/hrtimer.c:1994
hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061
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:63
Code: d6 88 02 e9 83 42 03 00 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 b0 13 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e407e00 EFLAGS: 00000246
RAX: 0000000002d05a33 RBX: ffffffff8e4955c0 RCX: ffffffff8b97e045
RDX: 0000000000000000 RSI: ffffffff8df53c55 RDI: ffffffff8c1c0e00
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10170867ad
R10: ffff8880b8433d6b R11: 0000000000000000 R12: 0000000000000000
R13: fffffbfff1c92ab8 R14: 0000000000000000 R15: ffffffff90dbba50
arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x464/0x590 kernel/sched/idle.c:352
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451
rest_init+0x251/0x260 init/main.c:762
start_kernel+0x484/0x490 init/main.c:1220
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148
task:syz.5.1798 state:R running task stack:25896 pid:12290 tgid:12288 ppid:6807 task_flags:0x40044c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x10e9/0x6820 kernel/sched/core.c:7188
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7512
irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x1fe/0x790 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x19e/0x310 kernel/locking/lockdep.c:5893
Code: ff 65 0f c1 05 db 02 2e 12 83 f8 01 0f 85 28 01 00 00 9c 58 f6 c4 02 0f 85 13 01 00 00 41 f7 c6 00 02 00 00 0f 85 c0 00 00 00 <48> 8b 44 24 10 65 48 2b 05 2d bb 2d 12 0f 85 4e 01 00 00 48 83 c4
RSP: 0018:ffffc900091c6d78 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e7e5460 RCX: ffffc900091c6d84
RDX: 0000000000000001 RSI: ffffffff8df2e77a RDI: ffffffff8c1c0e00
RBP: ffffffff81b8a1ae R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 000000000000c65e R12: ffff888033242500
R13: ffffc900091c6e30 R14: 0000000000000202 R15: 0000000000000002
rcu_lock_release include/linux/rcupdate.h:310 [inline]
rcu_read_unlock include/linux/rcupdate.h:869 [inline]
class_rcu_destructor include/linux/rcupdate.h:1181 [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: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:1404 [inline]
free_unref_folios+0xa0d/0x16f0 mm/page_alloc.c:3006
folios_put_refs+0x53c/0x840 mm/swap.c:1002
free_pages_and_swap_cache+0x22d/0x3b0 mm/swap_state.c:401
__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+0xe9/0x590 mm/mmu_gather.c:424
zap_pte_range mm/memory.c:1957 [inline]
zap_pmd_range mm/memory.c:2004 [inline]
zap_pud_range mm/memory.c:2032 [inline]
zap_p4d_range mm/memory.c:2053 [inline]
__zap_vma_range+0x230e/0x4bf0 mm/memory.c:2093
unmap_vmas+0x299/0x5f0 mm/memory.c:2162
exit_mmap+0x1ef/0xa10 mm/mmap.c:1300
__mmput+0x12a/0x410 kernel/fork.c:1178
mmput+0x67/0x80 kernel/fork.c:1201
exit_mm kernel/exit.c:581 [inline]
do_exit+0x833/0x2a60 kernel/exit.c:963
do_group_exit+0xd5/0x2a0 kernel/exit.c:1117
get_signal+0x1ec7/0x21e0 kernel/signal.c:3037
arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x86/0x4a0 kernel/entry/common.c:98
__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:238 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline]
do_syscall_64+0x706/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f989b99c819
RSP: 002b:00007f989c7b8028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007f989bc16090 RCX: 00007f989b99c819
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f989ba32c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f989bc16128 R14: 00007f989bc16090 R15: 00007ffcd7d13378
task:dhcpcd state:R running task stack:22536 pid:5477 tgid:5477 ppid:5476 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x10e9/0x6820 kernel/sched/core.c:7188
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7512
irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x1fe/0x790 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0x4d6/0x2090 arch/x86/kernel/unwind_orc.c:520
Code: e8 6f f3 ff ff 48 89 c1 48 85 c0 0f 84 dc 06 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8d 79 05 4c 89 fa 48 c1 ea 03 0f b6 04 02 <4c> 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 51 15 00 00 0f b6 41 05
RSP: 0018:ffffc9000346f4f0 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff91894de4
RDX: 1ffffffff23129bd RSI: 0000000000000000 RDI: ffffffff90fd436c
RBP: ffffc9000346f5a8 R08: ffffffff91894e14 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000016ad7 R12: ffffc9000346f5b0
R13: ffffc9000346f560 R14: ffffc9000346f595 R15: ffffffff91894de9
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: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:4569 [inline]
slab_alloc_node mm/slub.c:4898 [inline]
kmem_cache_alloc_node_noprof+0x25a/0x6f0 mm/slub.c:4950
__alloc_skb+0x140/0x710 net/core/skbuff.c:702
alloc_skb include/linux/skbuff.h:1383 [inline]
alloc_skb_with_frags+0xdd/0x760 net/core/skbuff.c:6734
sock_alloc_send_pskb+0x801/0x980 net/core/sock.c:2998
unix_dgram_sendmsg+0x3c7/0x1810 net/unix/af_unix.c:2131
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
__sys_sendto+0x468/0x4b0 net/socket.c:2265
__do_sys_sendto net/socket.c:2272 [inline]
__se_sys_sendto net/socket.c:2268 [inline]
__x64_sys_sendto+0xe0/0x1c0 net/socket.c:2268
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe2d4e3d407
RSP: 002b:00007ffed6964dd0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fe2d4db3780 RCX: 00007fe2d4e3d407
RDX: 000000000000003f RSI: 00007ffed6964f10 RDI: 0000000000000003
RBP: 00007ffed6965340 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffed6965790
R13: 00007ffed6964f10 R14: 000000000000001d R15: 00007ffed6964f10
task:syz.0.1799 state:R running task stack:26104 pid:12294 tgid:12293 ppid:5808 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x10e9/0x6820 kernel/sched/core.c:7188
preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7369
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline]
_raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:190
spin_unlock include/linux/spinlock.h:390 [inline]
wp_page_copy mm/memory.c:3960 [inline]
do_wp_page+0x13d2/0x4380 mm/memory.c:4320
handle_pte_fault mm/memory.c:6427 [inline]
__handle_mm_fault+0x1ab6/0x2a00 mm/memory.c:6549
handle_mm_fault+0x36d/0xa20 mm/memory.c:6718
do_user_addr_fault+0x74c/0x12f0 arch/x86/mm/fault.c:1385
handle_page_fault arch/x86/mm/fault.c:1474 [inline]
exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0010:__put_user_nocheck_4+0x3/0x10 arch/x86/lib/putuser.S:104
Code: d9 0f 01 cb 89 01 31 c9 0f 01 ca e9 97 d7 03 00 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 01 cb <89> 01 31 c9 0f 01 ca c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90007f679d8 EFLAGS: 00050287
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000020000002c030
RDX: 0000000000080000 RSI: ffffffff895a4f71 RDI: ffff88802b034a00
RBP: ffffc90007f67d78 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
R13: 000020000002c000 R14: ffffc90007f67dbc R15: 0000000000000002
____sys_recvmsg+0x2ec/0x640 net/socket.c:2931
___sys_recvmsg+0x16a/0x1a0 net/socket.c:2960
do_recvmmsg+0x301/0x760 net/socket.c:3055
__sys_recvmmsg net/socket.c:3129 [inline]
__do_sys_recvmmsg net/socket.c:3152 [inline]
__se_sys_recvmmsg net/socket.c:3145 [inline]
__x64_sys_recvmmsg+0x22a/0x280 net/socket.c:3145
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fba36b9c819
RSP: 002b:00007fba34df6028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fba36e15fa0 RCX: 00007fba36b9c819
RDX: 00000000080002c1 RSI: 0000200000000040 RDI: 0000000000000004
RBP: 00007fba36c32c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fba36e16038 R14: 00007fba36e15fa0 R15: 00007ffde9d1b3e8
rcu: rcu_preempt kthread starved for 4035 jiffies! g61153 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:27848 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x10e9/0x6820 kernel/sched/core.c:7188
__schedule_loop kernel/sched/core.c:7267 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7282
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
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: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: d6 88 02 e9 83 42 03 00 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 b0 13 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df0 EFLAGS: 00000246
RAX: 00000000023faee7 RBX: ffff88801e6f2500 RCX: ffffffff8b97e045
RDX: 0000000000000000 RSI: ffffffff8df53c55 RDI: ffffffff8c1c0e00
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10170a67ad
R10: ffff8880b8533d6b R11: 0000000000000000 R12: 0000000000000001
R13: ffffed1003cde4a0 R14: 0000000000000001 R15: ffffffff90dbba50
FS: 0000000000000000(0000) GS:ffff8881243ef000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe498ad7654 CR3: 000000002d7fc000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x464/0x590 kernel/sched/idle.c:352
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x148
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)