GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9410/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=27809, q=707 ncpus=2)
task:syz.2.923 state:R running task stack:26040 pid:9410 tgid:9404 ppid:5818 task_flags:0x40044c flags:0x00004002
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 cb d3 d3 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:ffffc900001e6d18 EFLAGS: 00000206
RAX: fd4bac4d84019d00 RBX: 0000000000000000 RCX: fd4bac4d84019d00
RDX: 0000000000000001 RSI: ffffffff8d91f7da RDI: ffffffff8bc0fa20
RBP: ffffffff817199f5 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff817199f5 R12: 0000000000000002
R13: ffffffff8df3b860 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:1262 [inline]
free_unref_folios+0xb70/0x1490 mm/page_alloc.c:2782
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+0x1d1/0x260 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: 0033:0x7f05dcb8e969
RSP: 002b:00007f05dd9f8038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007f05dcdb6080 RCX: 00007f05dcb8e969
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000005
RBP: 00007f05dcc10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f05dcdb6080 R15: 00007ffdca9b4478
rcu: rcu_preempt kthread timer wakeup didn't happen for 10547 jiffies! g27809 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=31006
rcu: rcu_preempt kthread starved for 10548 jiffies! g27809 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+0x70e/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:
CPU: 1 UID: 0 PID: 1299 Comm: aoe_tx0 Not tainted 6.15.0-rc4-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 fb 20 76 f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 f3 a2 3f f6 65 8b 05 bc c5 20 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc90004977740 EFLAGS: 00000206
RAX: 7d9f0b68df1e0c00 RBX: 0000000000000a06 RCX: 7d9f0b68df1e0c00
RDX: 0000000000000002 RSI: ffffffff8d735765 RDI: 0000000000000001
RBP: ffffc900049777d0 R08: ffffffff8f7d9f77 R09: 1ffffffff1efb3ee
R10: dffffc0000000000 R11: fffffbfff1efb3ef R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff99b16480 R15: 1ffff9200092eee8
FS: 0000000000000000(0000) GS:ffff888126202000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7df4727d58 CR3: 0000000060896000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000001d9e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
uart_port_unlock_irqrestore include/linux/serial_core.h:786 [inline]
uart_write+0x4cd/0xa40 drivers/tty/serial/serial_core.c:628
handle_tx+0x23c/0x610 drivers/net/caif/caif_serial.c:222
__netdev_start_xmit include/linux/netdevice.h:5203 [inline]
netdev_start_xmit include/linux/netdevice.h:5212 [inline]
xmit_one net/core/dev.c:3776 [inline]
dev_hard_start_xmit+0x2ff/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+0x70e/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