rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7799/1:b..l P7801/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=18573, q=477 ncpus=2)
task:syz.3.424 state:Z running task stack:28184 pid:7801 tgid:7801 ppid:5820 task_flags:0x40004c flags:0x00080001
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:lock_acquire+0x62/0x330 kernel/locking/lockdep.c:5872
Code: b4 18 12 83 f8 07 0f 87 a2 02 00 00 89 c0 48 0f a3 05 72 b9 ee 0e 0f 82 74 02 00 00 8b 35 0a ea ee 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 89 b4 18 12 0f 85 ad 02 00 00 48 83 c4
RSP: 0018:ffffc9000c3e7d50 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3c96a0 RCX: 0000000068c1bacb
RDX: 0000000000000000 RSI: ffffffff8daa7ea1 RDI: ffffffff8bf2b400
RBP: 0000000000000002 R08: 00000000ffffffff R09: 00000000ffffffff
R10: 0000000000000002 R11: ffff888057b7d4b0 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
percpu_ref_put_many include/linux/percpu-refcount.h:330 [inline]
percpu_ref_put include/linux/percpu-refcount.h:351 [inline]
obj_cgroup_put include/linux/memcontrol.h:793 [inline]
obj_cgroup_put include/linux/memcontrol.h:790 [inline]
__memcg_kmem_uncharge_page+0x8a/0x1c0 mm/memcontrol.c:2892
memcg_kmem_uncharge_page include/linux/memcontrol.h:1718 [inline]
exit_task_stack_account+0xb7/0x110 kernel/fork.c:508
do_exit+0x1586/0x2bd0 kernel/exit.c:1004
__do_sys_exit kernel/exit.c:1079 [inline]
__se_sys_exit kernel/exit.c:1077 [inline]
__x64_sys_exit+0x42/0x50 kernel/exit.c:1077
x64_sys_call+0x1517/0x1740 arch/x86/include/generated/asm/syscalls_64.h:61
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: 0033:0x7f94a298f749
RSP: 002b:00007f94a3899fe8 EFLAGS: 00000246 ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 00007f94a2be6090 RCX: 00007f94a298f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f94a2a13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f94a2be6128 R14: 00007f94a2be6090 R15: 00007ffe56aa2e58
task:iou-wrk-7790 state:R running task stack:27288 pid:7799 tgid:7788 ppid:5806 task_flags:0x404050 flags:0x00080002
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_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x62/0x330 kernel/locking/lockdep.c:5872
Code: b4 18 12 83 f8 07 0f 87 a2 02 00 00 89 c0 48 0f a3 05 72 b9 ee 0e 0f 82 74 02 00 00 8b 35 0a ea ee 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 89 b4 18 12 0f 85 ad 02 00 00 48 83 c4
RSP: 0018:ffffc9000c407658 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3c96a0 RCX: 00000000ea3013be
RDX: 0000000000000000 RSI: ffffffff8daa7ea1 RDI: ffffffff8bf2b400
RBP: 0000000000000002 R08: 00000000552a9780 R09: 000000000552a978
R10: 0000000000000002 R11: ffff88802c3254b0 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xd1/0x20b0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:414
kmalloc_noprof include/linux/slab.h:957 [inline]
io_add_buffers io_uring/kbuf.c:535 [inline]
__io_manage_buffers_legacy io_uring/kbuf.c:577 [inline]
io_manage_buffers_legacy+0x3ce/0xe70 io_uring/kbuf.c:590
__io_issue_sqe+0xe8/0x7c0 io_uring/io_uring.c:1792
io_issue_sqe+0x85/0x1410 io_uring/io_uring.c:1815
io_wq_submit_work+0x3b9/0xed0 io_uring/io_uring.c:1927
io_worker_handle_work+0x639/0x16f0 io_uring/io-wq.c:650
io_wq_worker+0x35f/0xdd0 io_uring/io-wq.c:704
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: rcu_preempt kthread starved for 10557 jiffies! g18573 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:28440 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: 1 UID: 0 PID: 7787 Comm: syz.1.422 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:write_comp_data+0x3/0x90 kernel/kcov.c:240
Code: eb d0 f3 11 48 8b 80 60 16 00 00 c3 cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 49 89 d2 <49> 89 f8 49 89 f1 65 48 8b 15 b7 d0 f3 11 65 8b 05 c8 d0 f3 11 a9
RSP: 0018:ffffc9000d3d7d58 EFLAGS: 00000246
RAX: 0000000000080000 RBX: ffffc9000d3d7f48 RCX: ffffffff81bf5916
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffc9000d3d7e08
R13: ffff888028544980 R14: 0000000000000000 R15: 1ffff92001a7afbd
FS: 00007fa70e6086c0(0000) GS:ffff8881249f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000100 CR3: 000000002ea29000 CR4: 00000000003526f0
Call Trace:
syscall_get_arguments arch/x86/include/asm/syscall.h:124 [inline]
populate_seccomp_data+0x126/0x540 kernel/seccomp.c:256
__seccomp_filter+0x8e/0x11f0 kernel/seccomp.c:1272
__secure_computing+0x287/0x3b0 kernel/seccomp.c:1404
syscall_trace_enter+0x89/0x220 kernel/entry/syscall-common.c:44
syscall_enter_from_user_mode_work include/linux/entry-common.h:78 [inline]
syscall_enter_from_user_mode include/linux/entry-common.h:109 [inline]
do_syscall_64+0x42b/0xf80 arch/x86/entry/syscall_64.c:90
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa70d78f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa70e6080e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fa70d9e5fa8 RCX: 00007fa70d78f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa70d9e5fa8
RBP: 00007fa70d9e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa70d9e6038 R14: 00007ffc87a3f6d0 R15: 00007ffc87a3f7b8