rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P22639/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=151293, q=233 ncpus=2)
task:syz-executor state:R running task stack:24056 pid:22639 tgid:22639 ppid:22636 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0xbce/0x20b0 arch/x86/kernel/unwind_orc.c:605
Code: 03 4c 8b 44 24 28 80 3c 16 00 0f 85 e4 10 00 00 48 8b 14 24 49 89 45 48 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 <0f> 85 a2 10 00 00 4c 89 e2 4d 89 75 38 48 b8 00 00 00 00 00 fc ff
RSP: 0018:ffffc900038bf990 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffffff912fc6d0
RDX: 1ffff92000717f47 RSI: 1ffff92000717f49 RDI: ffffc900038bfd78
RBP: ffffc900038bfa48 R08: ffffffff912fc6d4 R09: 000000003a20f2d2
R10: 0000000000000002 R11: 000000000001288e R12: ffffc900038bfa50
R13: ffffc900038bfa00 R14: ffffc900038bfd80 R15: ffffc900038bfa34
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x160/0x1f0 mm/page_owner.c:165
__reset_page_owner+0x84/0x1a0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1406 [inline]
__free_frozen_pages+0x7df/0x1170 mm/page_alloc.c:2943
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4c/0xf0 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_noprof+0x25e/0x770 mm/slub.c:5270
getname_flags.part.0+0x4c/0x550 fs/namei.c:146
getname_flags+0x93/0xf0 include/linux/audit.h:345
user_path_at+0x24/0x60 fs/namei.c:3575
ksys_umount fs/namespace.c:2058 [inline]
__do_sys_umount fs/namespace.c:2066 [inline]
__se_sys_umount fs/namespace.c:2064 [inline]
__x64_sys_umount+0x10a/0x1a0 fs/namespace.c:2064
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4970990a77
RSP: 002b:00007ffd7cec2ee8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4970990a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd7cec2fa0
RBP: 00007ffd7cec2fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd7cec4030
R13: 00007f4970a13d7d R14: 00000000001bab5c R15: 00007ffd7cec4070
rcu: rcu_preempt kthread starved for 10537 jiffies! g151293 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:28360 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 27064 Comm: iou-sqp-27063 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:io_sq_thread+0x804/0x1e30 io_uring/sqpoll.c:344
Code: 00 00 c6 44 24 08 01 bb 01 00 00 00 e8 45 1f 1a fd 49 8d be d8 04 00 00 48 89 f8 48 c1 e8 03 42 80 3c 38 00 0f 85 f3 11 00 00 <49> 8b 86 d8 04 00 00 4c 8d b0 28 fb ff ff 48 39 44 24 10 0f 84 a4
RSP: 0018:ffffc9000431fca0 EFLAGS: 00000246
RAX: 1ffff1100a39f89b RBX: 0000000000000000 RCX: ffffffff84a4caf4
RDX: ffff88807e270000 RSI: ffffffff84a4c9ab RDI: ffff888051cfc4d8
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: ffff88807e270b30 R12: 0000000000000000
R13: ffff88807db16000 R14: ffff888051cfc000 R15: dffffc0000000000
FS: 00007fdca56586c0(0000) GS:ffff8881248f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffe70 CR3: 0000000036b40000 CR4: 00000000003526f0
Call Trace:
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246