rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=391c/1/0x4000000000000000 softirq=46755/46759 fqs=2
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8076/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=32477, q=633 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5209 Comm: udevd Not tainted 6.15.0-rc2-syzkaller-00493-gac71fabf1567 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:151 [inline]
RIP: 0010:lock_release+0x224/0x3e0 kernel/locking/lockdep.c:5890
Code: c7 c4 b4 4d 8e e8 cc 45 91 0a b8 ff ff ff ff 65 0f c1 05 ff 21 ca 11 83 f8 01 0f 85 bf 00 00 00 48 c7 44 24 20 00 00 00 00 9c <8f> 44 24 20 f7 44 24 20 00 02 00 00 0f 85 c3 00 00 00 41 f7 c6 00
RSP: 0018:ffffc90000a08bf0 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffffffff93686020 RCX: 0000000000000002
RDX: 0000000000010000 RSI: ffffffff8e4db4c4 RDI: ffffffff8ca1b680
RBP: ffff88807d9ec740 R08: ffff88803203a087 R09: 1ffff11006407410
R10: dffffc0000000000 R11: ffffed1006407411 R12: 0000000000000002
R13: ffff88807d9ebc00 R14: 0000000000000002 R15: ffff888011ce0300
FS: 00007f6d14127c80(0000) GS:ffff88812509a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000240 CR3: 0000000031a9c000 CR4: 0000000000350ef0
Call Trace:
__raw_spin_unlock include/linux/spinlock_api_smp.h:141 [inline]
_raw_spin_unlock+0x16/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
advance_sched+0x9b4/0xca0 net/sched/sch_taprio.c:981
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x5a8/0xd40 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
__sysvec_apic_timer_interrupt+0x112/0x420 arch/x86/kernel/apic/apic.c:1055
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_is_held_type+0x148/0x1a0 arch/x86/include/asm/irqflags.h:-1
Code: 07 83 f8 01 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 48 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 45 00 <48> 3b 44 24 08 75 42 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc900042af718 EFLAGS: 00000206
RAX: bae2e85f347d6e00 RBX: 0000000000000001 RCX: 0000000080000000
RDX: ffff88807d9ebc00 RSI: ffffffff8e4db4c4 RDI: ffffffff8ca1b680
RBP: ffffffff93686020 R08: ffffffff826b6f2e R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88807d9ebc00
R13: 0000000000000246 R14: 00000000ffffffff R15: ffffffff8ed3df20
kernfs_root+0xf7/0x230 fs/kernfs/kernfs-internal.h:74
kernfs_active fs/kernfs/dir.c:41 [inline]
kernfs_dop_revalidate+0xd8/0x5d0 fs/kernfs/dir.c:1181
lookup_fast+0x255/0x5a0 fs/namei.c:-1
walk_component fs/namei.c:2134 [inline]
link_path_walk+0x662/0xeb0 fs/namei.c:2503
path_openat+0x26d/0x35d0 fs/namei.c:4035
do_filp_open+0x284/0x4e0 fs/namei.c:4066
do_sys_openat2+0x12b/0x1d0 fs/open.c:1429
do_sys_open fs/open.c:1444 [inline]
__do_sys_openat fs/open.c:1460 [inline]
__se_sys_openat fs/open.c:1455 [inline]
__x64_sys_openat+0x249/0x2a0 fs/open.c:1455
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6d13d1a477
Code: 10 00 00 00 44 8b 54 24 e0 48 89 44 24 c0 48 8d 44 24 d0 48 89 44 24 c8 44 89 c2 4c 89 ce bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 10 48 8b 15 82 69 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007fff833e40d8 EFLAGS: 00000287 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 000055622f4ed750 RCX: 00007f6d13d1a477
RDX: 0000000000090800 RSI: 000055622f4f89d0 RDI: 00000000ffffff9c
RBP: 000055622f5a2ca0 R08: 0000000000090800 R09: 000055622f4f89d0
R10: 0000000000000000 R11: 0000000000000287 R12: 000055622f4f89d0
R13: 00000000000000fe R14: 000055621bcb21c4 R15: 0000000000000000
task:syz-executor state:R running task stack:21256 pid:8076 tgid:8076 ppid:8059 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x1b88/0x5240 kernel/sched/core.c:6767
preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6947
preempt_schedule+0xe4/0xf0 kernel/sched/core.c:6971
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
copy_pte_range+0x5e5f/0x6680 mm/memory.c:1194
copy_pmd_range mm/memory.c:1255 [inline]
copy_pud_range mm/memory.c:1292 [inline]
copy_p4d_range mm/memory.c:1316 [inline]
copy_page_range+0xe57/0x13a0 mm/memory.c:1410
dup_mmap kernel/fork.c:726 [inline]
dup_mm kernel/fork.c:1734 [inline]
copy_mm+0x130d/0x22c0 kernel/fork.c:1786
copy_process+0x17de/0x3d10 kernel/fork.c:2429
kernel_clone+0x242/0x930 kernel/fork.c:2844
__do_sys_clone kernel/fork.c:2987 [inline]
__se_sys_clone kernel/fork.c:2971 [inline]
__x64_sys_clone+0x268/0x2e0 kernel/fork.c:2971
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7d6eb849d3
RSP: 002b:00007ffef006c0e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7d6eb849d3
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 000055558b9a87d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 00000000000ab901 R15: 00007ffef006c280
rcu: rcu_preempt kthread starved for 10498 jiffies! g32477 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:26216 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x1b88/0x5240 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x163/0x360 kernel/sched/core.c:6860
schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046
rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248
kthread+0x7b9/0x940 kernel/kthread.c:464
ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153
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: 9600 Comm: syz-executor Not tainted 6.15.0-rc2-syzkaller-00493-gac71fabf1567 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216
Code: 8b 3d 34 07 b7 0c 48 89 de 5b e9 03 c7 5e 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 60 68 93 65 8b 15 f8 a2 a5 11 81 e2 00 01 ff 00
RSP: 0018:ffffc9000ebaf4b8 EFLAGS: 00000202
RAX: ffffffff81b6e40d RBX: 1ffff110170e7e91 RCX: ffff888036153c00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000ebaf6c0 R08: ffffffff81b6e3d8 R09: 1ffffffff20bfcae
R10: dffffc0000000000 R11: fffffbfff20bfcaf R12: ffff8880b863ad08
R13: ffff8880b873f488 R14: ffff8880b863ad00 R15: 0000000000000001
FS: 000055556bf67500(0000) GS:ffff888124f9a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555574b92808 CR3: 0000000064b30000 CR4: 0000000000350ef0
Call Trace:
csd_lock_wait kernel/smp.c:340 [inline]
smp_call_function_many_cond+0x1bcd/0x2d40 kernel/smp.c:885
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1275 [inline]
flush_tlb_mm_range+0xb8d/0x13f0 arch/x86/mm/tlb.c:1365
dup_mmap kernel/fork.c:765 [inline]
dup_mm kernel/fork.c:1734 [inline]
copy_mm+0x19de/0x22c0 kernel/fork.c:1786
copy_process+0x17de/0x3d10 kernel/fork.c:2429
kernel_clone+0x242/0x930 kernel/fork.c:2844
__do_sys_clone kernel/fork.c:2987 [inline]
__se_sys_clone kernel/fork.c:2971 [inline]
__x64_sys_clone+0x268/0x2e0 kernel/fork.c:2971
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f68d8d849d3
Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00
RSP: 002b:00007fff8a700678 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f68d8d849d3
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 000055556bf677d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 00000000000abc9b R15: 00007fff8a700810