rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8001/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=23069, q=781 ncpus=2)
task:syz.7.429 state:R running task stack:24280 pid:8001 tgid:8001 ppid:6829 task_flags:0x40044c flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090
irqentry_exit+0x6f/0x90 kernel/entry/common.c:354
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5870
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 6b 60 d4 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90003aeed18 EFLAGS: 00000206
RAX: 271698b120e8a300 RBX: 0000000000000000 RCX: 271698b120e8a300
RDX: 0000000000000001 RSI: ffffffff8d9245d7 RDI: ffffffff8bc11fc0
RBP: ffffffff8171ca05 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8171ca05 R12: 0000000000000002
R13: ffffffff8df3dee0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf7/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1258 [inline]
free_unref_folios+0xb70/0x1490 mm/page_alloc.c:2778
folios_put_refs+0x559/0x640 mm/swap.c:992
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1125
shmem_truncate_range mm/shmem.c:1237 [inline]
shmem_evict_inode+0x272/0xa70 mm/shmem.c:1365
evict+0x501/0x9c0 fs/inode.c:810
__dentry_kill+0x209/0x660 fs/dcache.c:660
dput+0x19f/0x2b0 fs/dcache.c:902
__fput+0x68e/0xa70 fs/file_table.c:473
task_work_run+0x1d4/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x8d6/0x2550 kernel/exit.c:953
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
get_signal+0x125e/0x1310 kernel/signal.c:3034
arch_do_signal_or_restart+0x95/0x780 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x8b/0x120 kernel/entry/common.c:218
do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f00a678e969
RSP: 002b:00007ffd1e095fc8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f00a69b7ba0 RCX: 00007f00a678e969
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f00a69b7ba0 R08: 000000000000300c R09: 0000001b1e0962bf
R10: 00007f00a69b7ac0 R11: 0000000000000246 R12: 000000000004c3aa
R13: 00007f00a69b6160 R14: ffffffffffffffff R15: 00007ffd1e0960e0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10557 jiffies! g23069 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=18170
rcu: rcu_preempt kthread starved for 10558 jiffies! g23069 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27304 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2046
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2248
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 1301 Comm: aoe_tx0 Not tainted 6.15.0-rc7-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_preemption_disabled+0x1e/0x120 lib/smp_processor_id.c:16
Code: 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 48 83 ec 10 65 48 8b 05 4e 0e 23 07 48 89 44 24 08 65 8b 05 56 0e 23 07 <65> 8b 0d 4b 0e 23 07 f7 c1 ff ff ff 7f 74 23 65 48 8b 0d 2b 0e 23
RSP: 0018:ffffc9000418f6f0 EFLAGS: 00000086
RAX: 0000000000000001 RBX: ffffffff8b51f772 RCX: 0000000000000000
RDX: ffff888027265a00 RSI: ffffffff8d78ae75 RDI: ffffffff8bc11fc0
RBP: ffffc9000418f7e0 R08: ffff888023fc0f87 R09: 1ffff110047f81f0
R10: dffffc0000000000 R11: ffffed10047f81f1 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000a02 R15: 1ffff92000831eec
FS: 0000000000000000(0000) GS:ffff8881261f6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1e0898e368 CR3: 000000007b606000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lockdep_hardirqs_off+0xab/0x110 kernel/locking/lockdep.c:4496
trace_hardirqs_off+0x12/0x40 kernel/trace/trace_preemptirq.c:104
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline]
_raw_spin_lock_irqsave+0x82/0xf0 kernel/locking/spinlock.c:162
uart_port_lock_irqsave include/linux/serial_core.h:715 [inline]
uart_write_room+0xf0/0x840 drivers/tty/serial/serial_core.c:647
handle_tx+0x163/0x610 drivers/net/caif/caif_serial.c:212
__netdev_start_xmit include/linux/netdevice.h:5204 [inline]
netdev_start_xmit include/linux/netdevice.h:5213 [inline]
xmit_one net/core/dev.c:3776 [inline]
dev_hard_start_xmit+0x302/0x880 net/core/dev.c:3792
__dev_queue_xmit+0x1adf/0x3a70 net/core/dev.c:4629
dev_queue_xmit include/linux/netdevice.h:3350 [inline]
tx+0x6b/0x190 drivers/block/aoe/aoenet.c:62
kthread+0x1cd/0x3e0 drivers/block/aoe/aoecmd.c:1237
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245