rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=263c/1/0x4000000000000000 softirq=126063/126068 fqs=4
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13027/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=118797, q=1893 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 20540 Comm: syz.4.2600 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3801 [inline]
RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3821 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3876 [inline]
RIP: 0010:__lock_acquire+0xb17/0x2cf0 kernel/locking/lockdep.c:5237
Code: 4e 92 0e 48 c7 c6 54 28 0c 8e 67 48 0f b9 3a 90 48 bb eb 83 b5 80 46 86 c8 61 48 0f af dd 48 c1 eb 2d 48 8b 04 dd a0 03 fd 93 <48> 85 c0 0f 94 c1 48 83 c0 f8 0f 94 c2 08 ca 0f 84 1c 01 00 00 e8
RSP: 0018:ffffc90000a08b40 EFLAGS: 00000012
RAX: ffffffff9441b3f8 RBX: 0000000000022c26 RCX: 0000000000040000
RDX: 00000000d890a6cc RSI: 00000000e3c36222 RDI: ffff88802a66dc40
RBP: cc889bfc2cd708a8 R08: ffffffff84bc9063 R09: ffffffff9a726c40
R10: dffffc0000000000 R11: fffff520001411ac R12: ffff88802a66e820
R13: ffff88802a66e820 R14: ffff88802a66dc40 R15: 0000000000000002
FS: 00007f1d071f66c0(0000) GS:ffff88812538d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff85855c000 CR3: 00000000207a5000 CR4: 0000000000350ef0
Call Trace:
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
_raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166
debug_object_activate+0x83/0x580 lib/debugobjects.c:835
debug_hrtimer_activate kernel/time/hrtimer.c:485 [inline]
debug_activate kernel/time/hrtimer.c:528 [inline]
enqueue_hrtimer+0xa9/0x2c0 kernel/time/hrtimer.c:1109
__run_hrtimer kernel/time/hrtimer.c:1946 [inline]
__hrtimer_run_queues+0x4d2/0xa20 kernel/time/hrtimer.c:1994
hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:is_kfence_address include/linux/kfence.h:58 [inline]
RIP: 0010:obj_to_index mm/slab.h:303 [inline]
RIP: 0010:__memcg_slab_post_alloc_hook+0x9fd/0xe80 mm/memcontrol.c:3507
Code: e8 c8 b9 f7 ff 4c 8b 2b 48 8b 84 24 98 00 00 00 42 80 3c 20 00 74 0c 48 c7 c7 d8 b7 30 90 e8 aa b9 f7 ff 48 8b 05 9b 76 f7 0d <48> 85 c0 74 15 4c 89 e9 48 29 c1 31 db 48 81 f9 00 00 20 00 0f 82
RSP: 0018:ffffc90004276998 EFLAGS: 00000246
RAX: ffff88823be00000 RBX: ffffc90004276ab0 RCX: 0000000083a34001
RDX: 0000000000000001 RSI: ffffffff8e219861 RDI: 00000000ffffffff
RBP: ffffea0000d00b80 R08: 0000000000000005 R09: ffff8880b873c480
R10: 0000000000000012 R11: ffffffff81b0e910 R12: dffffc0000000000
R13: ffff88803402e3a0 R14: ffffea0000d00bb8 R15: ffff888083a34000
memcg_slab_post_alloc_hook mm/slub.c:2461 [inline]
slab_post_alloc_hook mm/slub.c:4580 [inline]
slab_alloc_node mm/slub.c:4898 [inline]
kmem_cache_alloc_noprof+0x347/0x650 mm/slub.c:4905
alloc_buffer_head+0x2a/0x270 fs/buffer.c:2941
folio_alloc_buffers+0x19b/0x640 fs/buffer.c:838
grow_dev_folio fs/buffer.c:979 [inline]
grow_buffers fs/buffer.c:1020 [inline]
__getblk_slow fs/buffer.c:1038 [inline]
bdev_getblk+0x2cb/0x6e0 fs/buffer.c:1358
__getblk include/linux/buffer_head.h:380 [inline]
do_readahead fs/jbd2/recovery.c:95 [inline]
jread+0x476/0xae0 fs/jbd2/recovery.c:160
do_one_pass+0x3e0/0x2ef0 fs/jbd2/recovery.c:673
jbd2_journal_skip_recovery+0xb3/0x220 fs/jbd2/recovery.c:368
jbd2_journal_wipe+0xc6/0x110 fs/jbd2/journal.c:2514
ocfs2_journal_wipe+0xa3/0x280 fs/ocfs2/journal.c:1209
ocfs2_check_volume fs/ocfs2/super.c:2361 [inline]
ocfs2_mount_volume fs/ocfs2/super.c:1762 [inline]
ocfs2_fill_super+0x49a1/0x6970 fs/ocfs2/super.c:1083
get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
vfs_get_tree+0x92/0x2a0 fs/super.c:1754
fc_mount fs/namespace.c:1193 [inline]
do_new_mount_fc fs/namespace.c:3758 [inline]
do_new_mount+0x341/0xd30 fs/namespace.c:3834
do_mount fs/namespace.c:4167 [inline]
__do_sys_mount fs/namespace.c:4383 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4360
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1d08f9e04a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1d071f5e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f1d071f5ee0 RCX: 00007f1d08f9e04a
RDX: 0000200000004440 RSI: 0000200000000040 RDI: 00007f1d071f5ea0
RBP: 0000200000004440 R08: 00007f1d071f5ee0 R09: 0000000001000cc0
R10: 0000000001000cc0 R11: 0000000000000246 R12: 0000200000000040
R13: 00007f1d071f5ea0 R14: 0000000000004428 R15: 0000200000000080
task:udevd state:R running task stack:23288 pid:13027 tgid:13027 ppid:4988 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x17b4/0x5680 kernel/sched/core.c:7189
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x14f/0x730 kernel/entry/common.c:164
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 51 f4 06 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 3b 7f 97 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 0b 90 6e ff cc 48 8d 3d c8 5a 92
RSP: 0018:ffffc900034176c8 EFLAGS: 00000282
RAX: 5d1dee9336837c00 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 000000002ad94000 RSI: ffffffff8e219861 RDI: ffffffff8c28ade0
RBP: ffffffff821d0f19 R08: ffffffff821d0f19 R09: ffffffff8e95cd60
R10: dffffc0000000000 R11: fffff52000682f49 R12: 0000000000000002
R13: ffffffff8e95cd60 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:838 [inline]
__pte_offset_map+0x45/0x240 mm/pgtable-generic.c:290
pte_offset_map_lock+0x46/0x210 mm/pgtable-generic.c:400
change_pte_range mm/mprotect.c:332 [inline]
change_pmd_range mm/mprotect.c:537 [inline]
change_pud_range mm/mprotect.c:600 [inline]
change_p4d_range mm/mprotect.c:626 [inline]
change_protection_range mm/mprotect.c:654 [inline]
change_protection+0x1354/0x4c70 mm/mprotect.c:688
mprotect_fixup+0x83e/0xb60 mm/mprotect.c:807
do_mprotect_pkey+0x8d5/0xd20 mm/mprotect.c:967
__do_sys_mprotect mm/mprotect.c:988 [inline]
__se_sys_mprotect mm/mprotect.c:985 [inline]
__x64_sys_mprotect+0x80/0x90 mm/mprotect.c:985
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff857f1dfe7
RSP: 002b:00007ffdea6c2b58 EFLAGS: 00000246 ORIG_RAX: 000000000000000a
RAX: ffffffffffffffda RBX: 0000000000000200 RCX: 00007ff857f1dfe7
RDX: 0000000000000001 RSI: 0000000000000200 RDI: 00007ff85855e000
RBP: 000055e9e30933b0 R08: 0000000000000000 R09: 0000000000000200
R10: 000055e9e3093410 R11: 0000000000000246 R12: 00000000000001f6
R13: 0000000000001e00 R14: 000055e9e308b1a8 R15: 00007ff85868e39c
rcu: rcu_preempt kthread starved for 10494 jiffies! g118797 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:27536 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x17b4/0x5680 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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: 20531 Comm: syz.1.2597 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:native_pause arch/x86/include/asm/vdso/processor.h:13 [inline]
RIP: 0010:cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline]
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xfcd/0x13d0 kernel/smp.c:892
Code: c0 75 79 45 8b 2e 44 89 ee 83 e6 01 31 ff e8 da 07 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 85 03 0c 00 eb 37 90 43 0f b6 04 2c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 6a
RSP: 0018:ffffc90004347580 EFLAGS: 00000293
RAX: ffffffff81b9bc06 RBX: ffff8880b863c148 RCX: ffff88802deb1ec0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900043476c0 R08: ffffffff9030adf7 R09: 1ffffffff20615be
R10: dffffc0000000000 R11: fffffbfff20615bf R12: 1ffff110170e8169
R13: dffffc0000000000 R14: ffff8880b8740b48 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88812528d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30322ff8 CR3: 000000002cfa5000 CR4: 0000000000350ef0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057
__flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
flush_tlb_mm_range+0x5c3/0x10b0 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:509 [inline]
tlb_flush_mmu+0x1af/0xa30 mm/mmu_gather.c:423
tlb_finish_mmu+0xf9/0x230 mm/mmu_gather.c:549
exit_mmap+0x498/0x9e0 mm/mmap.c:1313
__mmput+0x118/0x430 kernel/fork.c:1178
exit_mm+0x18e/0x250 kernel/exit.c:581
do_exit+0x6a2/0x22c0 kernel/exit.c:963
do_group_exit+0x21b/0x2d0 kernel/exit.c:1117
get_signal+0x1284/0x1330 kernel/signal.c:3037
arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x86/0x480 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:318 [inline]
do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f168815d60e
Code: Unable to access opcode bytes at 0x7f168815d5e4.
RSP: 002b:00007f16863f5f68 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: fffffffffffffe00 RBX: 00007f16863f66c0 RCX: 00007f168815d60e
RDX: 0000000000002000 RSI: 000020000000bb40 RDI: 000000000000000b
RBP: 00007f1688232d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000b
R13: 0000200000000840 R14: 00007f1688415fa0 R15: 00007ffef517c548