rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=83ec/1/0x4000000000000000 softirq=139616/139620 fqs=0
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P26237/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=150373, q=149 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 26236 Comm: syz.0.5308 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:mark_lock+0x9b/0x190 kernel/locking/lockdep.c:4731
Code: 00 75 19 90 48 c7 c7 47 13 d9 8d 48 c7 c6 fc 61 c8 8d e8 98 a1 e5 ff 90 0f 0b 90 90 90 31 c9 4c 89 fe 4c 89 f7 b8 01 00 00 00 <85> 69 60 74 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 49
RSP: 0018:ffffc90000a08af8 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000008 RCX: ffffffff93778598
RDX: 0000000000000008 RSI: ffff888030210b30 RDI: ffff888030210000
RBP: 0000000000000100 R08: 0000000000000000 R09: ffffffff89a337c4
R10: dffffc0000000000 R11: ffffffff89a33700 R12: ffffffffffffff03
R13: 0000000000000003 R14: ffff888030210b30 R15: 0000000000000000
FS: 00007f9bb081e6c0(0000) GS:ffff888125ae7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f590a5568c0 CR3: 000000007a9b0000 CR4: 00000000003526f0
Call Trace:
mark_usage kernel/locking/lockdep.c:4674 [inline]
__lock_acquire+0x6a8/0xd20 kernel/locking/lockdep.c:5191
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
advance_sched+0xc4/0xc90 net/sched/sch_taprio.c:929
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__sanitizer_cov_trace_pc+0x46/0x70 kernel/kcov.c:222
Code: ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 7c 16 00 00 00 74 2c 8b 91 58 16 00 00 83 fa 02 75 21 48 8b 91 60 16 00 00 48 8b 32 <48> 8d 7e 01 8b 89 5c 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2
RSP: 0018:ffffc90003eff9f8 EFLAGS: 00000246
RAX: ffffffff84ca63f6 RBX: 0000000000000000 RCX: ffff888030210000
RDX: ffffc90020c93000 RSI: 000000000007ffff RDI: 0000000000000000
RBP: 0000000000000008 R08: ffffc90003effba0 R09: ffffc90003effcf0
R10: ffffc90003effd30 R11: fffff520007dffa8 R12: 0000000000000000
R13: 0000000000000000 R14: ffffc90003effba0 R15: 0000000000000000
import_iovec+0x26/0xa0 lib/iov_iter.c:1427
copy_msghdr_from_user net/socket.c:2554 [inline]
recvmsg_copy_msghdr net/socket.c:2803 [inline]
___sys_recvmsg+0x43a/0x510 net/socket.c:2875
do_recvmmsg+0x307/0x770 net/socket.c:2974
__sys_recvmmsg net/socket.c:3048 [inline]
__do_sys_recvmmsg net/socket.c:3071 [inline]
__se_sys_recvmmsg net/socket.c:3064 [inline]
__x64_sys_recvmmsg+0x190/0x240 net/socket.c:3064
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9baf98ec29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9bb081e038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f9bafbd6090 RCX: 00007f9baf98ec29
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000006
RBP: 00007f9bafa11e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9bafbd6128 R14: 00007f9bafbd6090 R15: 00007ffc50d40058
task:syz-executor state:R running task stack:27112 pid:26237 tgid:26237 ppid:22421 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7291
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 4b 16 26 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900045176b8 EFLAGS: 00000206
RAX: 0a6545f4b8e2fe00 RBX: 0000000000000000 RCX: 0a6545f4b8e2fe00
RDX: 0000000000000000 RSI: ffffffff8dd9240a RDI: ffffffff8c03aa60
RBP: ffffffff8173bd25 R08: 0000000000000000 R09: ffffffff8173bd25
R10: ffffc90004517878 R11: ffffffff81ac5170 R12: 0000000000000002
R13: ffffffff8e33d260 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1169 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
unpoison_slab_object mm/kasan/common.c:342 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4945 [inline]
slab_alloc_node mm/slub.c:5244 [inline]
kmem_cache_alloc_lru_noprof+0x35d/0x6d0 mm/slub.c:5263
__d_alloc+0x36/0x7a0 fs/dcache.c:1690
d_alloc+0x4b/0x190 fs/dcache.c:1769
lookup_one_qstr_excl+0xdc/0x360 fs/namei.c:1701
filename_create+0x224/0x3c0 fs/namei.c:4148
do_symlinkat+0xbc/0x3f0 fs/namei.c:4757
__do_sys_symlinkat fs/namei.c:4780 [inline]
__se_sys_symlinkat fs/namei.c:4777 [inline]
__x64_sys_symlinkat+0x95/0xb0 fs/namei.c:4777
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f590a58e1a7
RSP: 002b:00007ffee65a6b28 EFLAGS: 00000206 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f590a58e1a7
RDX: 00007f590a6136f5 RSI: 00000000ffffff9c RDI: 00007ffee65a6bc0
RBP: 00007ffee65a6b6c R08: 0000000000000013 R09: 00007ffee65a6877
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000115
R13: 00000000000927c0 R14: 00000000001dd49a R15: 00007ffee65a6bc0
rcu: rcu_preempt kthread starved for 10502 jiffies! g150373 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:26464 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7046 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7061
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 26215 Comm: syz.8.5303 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xd33/0x12d0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 36 79 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 e1 74 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 c5 74
RSP: 0018:ffffc900043d7340 EFLAGS: 00000293
RAX: ffffffff81b4645b RBX: 1ffff110170e7ffd RCX: ffff888022b25ac0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900043d74c0 R08: ffffffff8fc39677 R09: 1ffffffff1f872ce
R10: dffffc0000000000 R11: fffffbfff1f872cf R12: ffff8880b873ffe8
R13: dffffc0000000000 R14: ffff8880b863b200 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8881259e7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbecacf1b45 CR3: 000000000e138000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1451
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline]
tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403
tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497
free_ldt_pgtables+0x17b/0x320 arch/x86/kernel/ldt.c:411
arch_exit_mmap arch/x86/include/asm/mmu_context.h:234 [inline]
exit_mmap+0x174/0xb40 mm/mmap.c:1266
__mmput+0x118/0x430 kernel/fork.c:1148
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x2300 kernel/exit.c:954
do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f91b318ec29
Code: Unable to access opcode bytes at 0x7f91b318ebff.
RSP: 002b:00007f91b3f520e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f91b33d6188 RCX: 00007f91b318ec29
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f91b33d6188
RBP: 00007f91b33d6180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f91b33d6218 R14: 00007fff45cc4c80 R15: 00007fff45cc4d68