rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=83b4/1/0x4000000000000000 softirq=17603/17604 fqs=1
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5217/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=11537, q=1151 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6228 Comm: modprobe Not tainted 6.16.0-rc4-syzkaller-00109-gb9fd9888a565 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__lock_acquire+0x6c9/0xd20 kernel/locking/lockdep.c:5210
Code: 08 00 00 00 e8 88 25 00 00 45 31 ff 85 c0 0f 84 f5 05 00 00 83 3d c6 36 0d 18 00 75 13 48 63 44 24 20 48 0f a3 05 57 a7 09 12 <0f> 83 15 05 00 00 31 ed 48 8b 3c 24 4c 8b bf e0 0a 00 00 48 83 7c
RSP: 0018:ffffc90000007b40 EFLAGS: 00000047
RAX: 0000000000000007 RBX: 0000000000000002 RCX: ffffffff9348e8a8
RDX: 0000000000000008 RSI: ffff888025f7a968 RDI: ffff888025f79e00
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff898ec538
R10: dffffc0000000000 R11: ffffed100f0a8a5e R12: 0000000000000003
R13: 0000000000000001 R14: ffff888025f7a968 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125c1d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f46043ea6b0 CR3: 000000000df38000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
advance_sched+0xa14/0xc90 net/sched/sch_taprio.c:985
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:102 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
RIP: 0010:unwind_next_frame+0x1318/0x2390 arch/x86/kernel/unwind_orc.c:494
Code: 4c 8d 3c 45 00 00 00 00 49 01 ef 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 27 49 63 07 4c 01 f8 <49> 8d 4f 04 4c 39 e0 48 0f 46 e9 49 8d 47 fc 48 0f 47 d8 4d 0f 46
RSP: 0018:ffffc9000c0af3b8 EFLAGS: 00000293
RAX: ffffffff8133714a RBX: ffffffff8fb24440 RCX: dffffc0000000000
RDX: ffffffff8fb24438 RSI: ffffffff902c665c RDI: ffffffff8be28f20
RBP: ffffffff8fb24438 R08: 000000000000000f R09: ffffffff81729af5
R10: ffffc9000c0af4d8 R11: ffffffff81acf6d0 R12: ffffffff81337149
R13: ffffffff8fb24438 R14: ffffc9000c0af488 R15: ffffffff8fb2443c
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:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2381 [inline]
slab_free mm/slub.c:4643 [inline]
kmem_cache_free+0x18f/0x400 mm/slub.c:4745
anon_vma_chain_free mm/rmap.c:147 [inline]
unlink_anon_vmas+0x2cc/0x670 mm/rmap.c:421
free_pgtables+0x7bf/0xaf0 mm/memory.c:402
exit_mmap+0x444/0xb50 mm/mmap.c:1295
__mmput+0x118/0x420 kernel/fork.c:1121
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x648/0x22e0 kernel/exit.c:952
do_group_exit+0x21c/0x2d0 kernel/exit.c:1105
__do_sys_exit_group kernel/exit.c:1116 [inline]
__se_sys_exit_group kernel/exit.c:1114 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1114
x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f46043ea6c5
Code: Unable to access opcode bytes at 0x7f46043ea69b.
RSP: 002b:00007ffc67f5a9e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f46044ebfe8 RCX: 00007f46043ea6c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000001
RBP: 0000000000000001 R08: 00007ffc67f5a978 R09: 0000000000000000
R10: 00007ffc67f5a810 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f46044ea680 R15: 00007f46044ec000
task:udevd state:R running task stack:25352 pid:5217 tgid:5217 ppid:1 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108
irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:lock_release+0x2b5/0x3e0 kernel/locking/lockdep.c:5896
Code: 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 9b ea 01 11 <48> 3b 44 24 28 0f 85 8b 00 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90003abf740 EFLAGS: 00000206
RAX: c6328647afd05700 RBX: 0000000000000202 RCX: c6328647afd05700
RDX: 0000000000000001 RSI: ffffffff8db84710 RDI: ffffffff8be28f80
RBP: ffff88807c244718 R08: 0000000000000000 R09: ffffffff825d8c5c
R10: dffffc0000000000 R11: ffffed1003bd1e01 R12: 0000000000000001
R13: 0000000000000001 R14: ffffffff8e13ee20 R15: ffff88807c243c00
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
kernfs_root+0x1e5/0x230 fs/kernfs/kernfs-internal.h:80
kernfs_root_is_locked fs/kernfs/kernfs-internal.h:109 [inline]
kernfs_parent+0x51/0x190 fs/kernfs/kernfs-internal.h:133
kernfs_dop_revalidate+0x265/0x5d0 fs/kernfs/dir.c:1186
d_revalidate fs/namei.c:929 [inline]
lookup_fast+0x253/0x5b0 fs/namei.c:-1
walk_component fs/namei.c:2134 [inline]
link_path_walk+0x642/0xea0 fs/namei.c:2506
path_openat+0x28c/0x3830 fs/namei.c:4051
do_filp_open+0x1fa/0x410 fs/namei.c:4082
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f80e9515c3a
RSP: 002b:00007ffd8e0ff908 EFLAGS: 00000206 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000555acfe95d50 RCX: 00007f80e9515c3a
RDX: 0000000000090800 RSI: 0000555acfdf6360 RDI: 00000000ffffff9c
RBP: 0000555acfdf6360 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000206 R12: 0000555acfe067d0
R13: 00000000000000ff R14: 0000555aa20bbbe0 R15: 00007ffd8e0ffb90
rcu: rcu_preempt kthread starved for 10498 jiffies! g11537 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:26632 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
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: 5852 Comm: syz-executor Not tainted 6.16.0-rc4-syzkaller-00109-gb9fd9888a565 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0xf69/0x12d0 kernel/smp.c:885
Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 c0 79 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 6b 75 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 50 75 0b
RSP: 0018:ffffc900040df560 EFLAGS: 00000293
RAX: ffffffff81b4e950 RBX: ffff8880b873b1c0 RCX: ffff888026983c00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900040df6c0 R08: ffffffff8fa1dcf7 R09: 1ffffffff1f43b9e
R10: dffffc0000000000 R11: fffffbfff1f43b9f R12: 1ffff110170c8385
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8641c28
FS: 0000555569980500(0000) GS:ffff888125d1d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f26e6ae56c0 CR3: 000000007427c000 CR4: 00000000003526f0
Call Trace:
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:1361 [inline]
flush_tlb_mm_range+0x6b1/0x12c0 arch/x86/mm/tlb.c:1451
dup_mmap+0x15a0/0x1ac0 mm/mmap.c:1877
dup_mm kernel/fork.c:1477 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1529
copy_process+0x1706/0x3c00 kernel/fork.c:2169
kernel_clone+0x21e/0x870 kernel/fork.c:2599
__do_sys_clone kernel/fork.c:2742 [inline]
__se_sys_clone kernel/fork.c:2726 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2726
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f26e5d85193
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:00007ffcb3d1f368 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f26e5d85193
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 00005555699807d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000001877a R15: 00007ffcb3d1f500