rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10237/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=42745, q=339 ncpus=2)
task:syz.0.1609 state:R running task stack:23736 pid:10237 tgid:10237 ppid:5613 task_flags:0x40064c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7228
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7552
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_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:679
RIP: 0010:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:396 [inline]
RIP: 0010:__rcu_read_unlock+0x3f/0x5e0 kernel/rcu/tree_plugin.h:435
Code: 12 48 8d bb c4 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 <84> d2 0f 85 0a 02 00 00 83 ab c4 04 00 00 01 75 3b 48 8d bb c8 04
RSP: 0018:ffffc90003586ef8 EFLAGS: 00000202
RAX: 0000000000000007 RBX: ffff88801efba540 RCX: ffffffff918b2101
RDX: 0000000000000000 RSI: ffffffff8c1e6100 RDI: ffff88801efbaa04
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90003586fa0 R11: 0000000000019541 R12: ffffc90003586ff0
R13: ffffc90003586fa0 R14: ffffc90003587a78 R15: ffffc90003586fd4
rcu_read_unlock include/linux/rcupdate.h:873 [inline]
class_rcu_destructor include/linux/rcupdate.h:1183 [inline]
unwind_next_frame+0x3c8/0x2090 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:1406 [inline]
free_unref_folios+0xa44/0x1710 mm/page_alloc.c:3011
folios_put_refs+0x585/0xaa0 mm/swap.c:1057
folio_batch_release include/linux/folio_batch.h:101 [inline]
shmem_undo_range+0x5e5/0x1570 mm/shmem.c:1149
shmem_truncate_range mm/shmem.c:1277 [inline]
shmem_evict_inode+0x3a5/0xbe0 mm/shmem.c:1407
evict+0x3c2/0xad0 fs/inode.c:828
iput_final fs/inode.c:2022 [inline]
iput.part.0+0x989/0x1050 fs/inode.c:2071
iput+0x35/0x40 fs/inode.c:2037
dentry_unlink_inode+0x284/0x470 fs/dcache.c:479
dentry_kill+0x25d/0xc20 fs/dcache.c:826
finish_dput fs/dcache.c:1001 [inline]
dput.part.0+0xd7/0x240 fs/dcache.c:1042
dput+0x1f/0x30 fs/dcache.c:1037
__fput+0x519/0xb50 fs/file_table.c:520
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x951/0x2ae0 kernel/exit.c:1004
do_group_exit+0xd5/0x2a0 kernel/exit.c:1147
get_signal+0x1ec7/0x21e0 kernel/signal.c:3038
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop kernel/entry/common.c:101 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline]
irqentry_exit+0x402/0xa00 kernel/entry/common.c:165
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7f5d50b9ce61
RSP: 002b:00000000fffffeb0 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f5d50e15fa0 RCX: 00007f5d50b9ce59
RDX: 0000000000000000 RSI: 00000000fffffeb0 RDI: 0000000000400000
RBP: 00007f5d50c32e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f5d50e16038 R14: 00007f5d50e15fa0 R15: 00007ffc2f047a98
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g42745 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=14217
rcu: rcu_preempt kthread starved for 10502 jiffies! g42745 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7322
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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5270 Comm: dhcpcd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:107 [inline]
RIP: 0010:raw_atomic_try_cmpxchg_acquire include/linux/atomic/atomic-arch-fallback.h:2170 [inline]
RIP: 0010:atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1302 [inline]
RIP: 0010:queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
RIP: 0010:do_raw_spin_lock+0x139/0x260 kernel/locking/spinlock_debug.c:116
Code: 28 00 00 00 00 e8 27 96 94 00 be 04 00 00 00 48 8d 7c 24 28 e8 18 96 94 00 8b 44 24 28 ba 01 00 00 00 89 44 24 04 f0 0f b1 13 <0f> 85 93 00 00 00 48 89 ea 65 44 8b 35 aa 5e 2b 12 48 b8 00 00 00
RSP: 0018:ffffc90000a08d50 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff88807dc082a8 RCX: ffffffff81e54168
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000a08d78
RBP: ffff88807dc082b0 R08: 0000000000000001 R09: fffff520001411af
R10: 0000000000000003 R11: ffffc90000a08ff8 R12: 1ffff920001411ab
R13: ffff88807dc082b8 R14: ffff8880b8528640 R15: ffff8880b8528690
FS: 00007fcd7b6c8780(0000) GS:ffff888124416000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc4069ea2f8 CR3: 000000007591b000 CR4: 00000000003526f0
Call Trace:
spin_lock include/linux/spinlock.h:342 [inline]
advance_sched+0xe5/0xd20 net/sched/sch_taprio.c:930
__run_hrtimer kernel/time/hrtimer.c:2032 [inline]
__hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096
hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:kasan_save_stack+0x28/0x50 mm/kasan/common.c:57
Code: 90 90 0f 1f 40 d6 41 54 31 c0 b9 40 00 00 00 41 89 f4 55 89 fd 31 d2 be 40 00 00 00 53 48 81 ec 00 02 00 00 48 89 e7 f3 48 ab <48> 89 e7 e8 30 cb 79 ff 44 89 e1 89 ea 89 c6 48 89 e7 e8 31 93 bb
RSP: 0018:ffffc9000377f6b0 EFLAGS: 00000282
RAX: 0000000000000000 RBX: ffff8880450010f0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffffc9000377f8b0
RBP: 0000000000400cc0 R08: 0000000000000000 R09: 0000000000000000
R10: ffff8880450010f0 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000400cc0 R14: ffff888045001000 R15: ffff8880b8543cf0
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:4610 [inline]
slab_alloc_node mm/slub.c:4939 [inline]
kmem_cache_alloc_node_noprof+0x25a/0x6f0 mm/slub.c:4991
__alloc_skb+0x140/0x710 net/core/skbuff.c:704
alloc_skb include/linux/skbuff.h:1384 [inline]
alloc_skb_with_frags+0xdd/0x760 net/core/skbuff.c:6769
sock_alloc_send_pskb+0x801/0x980 net/core/sock.c:3010
unix_dgram_sendmsg+0x3c7/0x1810 net/unix/af_unix.c:2136
sock_sendmsg_nosec net/socket.c:775 [inline]
__sock_sendmsg net/socket.c:790 [inline]
__sys_sendto+0x48b/0x4e0 net/socket.c:2252
__do_sys_sendto net/socket.c:2259 [inline]
__se_sys_sendto net/socket.c:2255 [inline]
__x64_sys_sendto+0xe0/0x1c0 net/socket.c:2255
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcd7b752407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007fff44054960 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fcd7b6c8780 RCX: 00007fcd7b752407
RDX: 000000000000003f RSI: 00007fff44054aa0 RDI: 0000000000000003
RBP: 00007fff44054ed0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007fff44055320
R13: 00007fff44054aa0 R14: 000000000000001d R15: 00007fff44054aa0