rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5866/1:b..l P5875/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=29713, q=425 ncpus=2)
task:syz-executor state:R running task stack:21736 pid:5875 tgid:5875 ppid:5858 task_flags:0x400140 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_notrace+0xd1/0x110 kernel/sched/core.c:7206
preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:752
rcu_read_unlock include/linux/rcupdate.h:895 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0x1965/0x2390 arch/x86/kernel/unwind_orc.c:680
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
__kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587
kasan_save_free_info mm/kasan/kasan.h:406 [inline]
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
kasan_slab_free include/linux/kasan.h:234 [inline]
slab_free_hook mm/slub.c:2507 [inline]
slab_free mm/slub.c:6557 [inline]
kmem_cache_free+0x19b/0x690 mm/slub.c:6668
free_buffer_head+0x55/0x220 fs/buffer.c:3041
try_to_free_buffers+0x232/0x2d0 fs/buffer.c:2982
block_invalidate_folio+0x5f7/0x730 fs/buffer.c:1674
folio_invalidate mm/truncate.c:140 [inline]
truncate_cleanup_folio+0x2d8/0x430 mm/truncate.c:160
truncate_inode_pages_range+0x233/0xda0 mm/truncate.c:379
ocfs2_evict_inode+0x1af/0x4100 fs/ocfs2/inode.c:1297
evict+0x504/0x9c0 fs/inode.c:810
ocfs2_dentry_iput+0x247/0x370 fs/ocfs2/dcache.c:407
__dentry_kill+0x209/0x660 fs/dcache.c:669
shrink_kill+0xa9/0x2c0 fs/dcache.c:1114
shrink_dentry_list+0x2e0/0x5e0 fs/dcache.c:1141
shrink_dcache_parent+0xa1/0x2c0 fs/dcache.c:-1
do_one_tree+0x23/0xe0 fs/dcache.c:1604
shrink_dcache_for_umount+0xa0/0x170 fs/dcache.c:1621
generic_shutdown_super+0x67/0x2c0 fs/super.c:620
kill_block_super+0x44/0x90 fs/super.c:1722
deactivate_locked_super+0xbc/0x130 fs/super.c:473
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1327
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43
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: 0033:0x7fe5305901f7
RSP: 002b:00007fffe61e7e18 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fe530611d7d RCX: 00007fe5305901f7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffe61e7ed0
RBP: 00007fffe61e7ed0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffe61e8f60
R13: 00007fe530611d7d R14: 0000000000000005 R15: 00007fffe61e8fa0
task:syz-executor state:R running task stack:18856 pid:5866 tgid:5866 ppid:5860 task_flags:0x400140 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:dentry_string_cmp fs/dcache.c:281 [inline]
RIP: 0010:dentry_cmp fs/dcache.c:321 [inline]
RIP: 0010:__d_lookup_rcu+0x2ee/0x490 fs/dcache.c:2313
Code: 24 0c c0 44 89 fd eb ab e8 3f cf 82 ff e9 e4 fe ff ff e8 35 cf 82 ff e9 da fe ff ff 49 c7 c7 ff ff ff ff 8b 4c 24 0c 49 d3 e7 <49> f7 d7 4c 31 f3 48 89 de 4c 21 fe 31 ff e8 ef d3 82 ff 4c 21 fb
RSP: 0018:ffffc9000416f9e8 EFLAGS: 00000287
RAX: ffffffff823d8ba2 RBX: 6f7267632f303131 RCX: 0000000000000018
RDX: ffff888027890000 RSI: 0000000000000003 RDI: 0000000000000008
RBP: 0000000000000003 R08: ffff888078ce1500 R09: 1ffff1100f19c2a0
R10: dffffc0000000000 R11: ffffed100f19c2a1 R12: ffff88807db52222
R13: ffff888078ce1500 R14: 0000000000303131 R15: ffffffffff000000
lookup_fast+0xdb/0x5b0 fs/namei.c:1750
walk_component fs/namei.c:2147 [inline]
link_path_walk+0x642/0xea0 fs/namei.c:2519
path_parentat fs/namei.c:2723 [inline]
__filename_parentat+0x246/0x670 fs/namei.c:2747
filename_parentat fs/namei.c:2765 [inline]
do_unlinkat+0xed/0x560 fs/namei.c:4712
__do_sys_unlink fs/namei.c:4783 [inline]
__se_sys_unlink fs/namei.c:4781 [inline]
__x64_sys_unlink+0x47/0x50 fs/namei.c:4781
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: 0033:0x7f078978e477
RSP: 002b:00007ffc3ad0e9e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f078978e477
RDX: 00007ffc3ad0ea10 RSI: 00007ffc3ad0eaa0 RDI: 00007ffc3ad0eaa0
RBP: 00007ffc3ad0eaa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffc3ad0fb30
R13: 00007f0789811d7d R14: 00000000000482f6 R15: 00007ffc3ad0fb70
rcu: rcu_preempt kthread starved for 10385 jiffies! g29713 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:26856 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
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: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 91 28 00 f3 0f 1e fa fb f4 c8 e6 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: 79b84628cf3dae00 RBX: ffffffff81972677 RCX: 79b84628cf3dae00
RDX: 0000000000000001 RSI: ffffffff8db9fb03 RDI: ffffffff8c03da60
RBP: ffffc90000197f10 R08: ffff8880b8732fdb R09: 1ffff110170e65fb
R10: dffffc0000000000 R11: ffffed10170e65fc R12: ffffffff8fc35770
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003ad2b58
FS: 0000000000000000(0000) GS:ffff888125afc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd94dc99cc1 CR3: 0000000053186000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x1e7/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x147