rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5852/1:b..l P13266/2:b..l
rcu: (detected by 0, t=10502 jiffies, g=48109, q=265 ncpus=2)
task:syz.1.1395 state:R running task stack:25864 pid:13266 tgid:13263 ppid:5861 task_flags:0x2040044c flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
irqentry_exit+0x36/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:121 [inline]
RIP: 0010:lock_acquire kernel/locking/lockdep.c:5844 [inline]
RIP: 0010:lock_acquire+0x111/0x350 kernel/locking/lockdep.c:5825
Code: ab 94 ff e9 45 ff ff ff 48 8b 74 24 68 48 89 df e8 c4 fa 89 00 8b 0d 32 d3 13 0f 85 c9 0f 84 b1 00 00 00 65 8b 05 97 27 3f 12 <85> c0 0f 85 a2 00 00 00 65 48 8b 05 d7 e5 3e 12 8b 90 ec 0a 00 00
RSP: 0018:ffffc90005a36c78 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffffffff8e5c1260 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff81cca306 RDI: fffffbfff1cb824c
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
is_bpf_text_address+0x36/0x1a0 kernel/bpf/core.c:776
kernel_text_address kernel/extable.c:125 [inline]
kernel_text_address+0x8d/0x100 kernel/extable.c:94
__kernel_text_address+0xd/0x40 kernel/extable.c:79
unwind_get_return_address+0x59/0xa0 arch/x86/kernel/unwind_orc.c:369
arch_stack_walk+0xa6/0x100 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:548
__call_rcu_common.constprop.0+0xa5/0xa10 kernel/rcu/tree.c:3123
slab_free_hook mm/slub.c:2386 [inline]
slab_free mm/slub.c:4695 [inline]
kmem_cache_free+0x16d/0x4d0 mm/slub.c:4797
mempool_free+0x102/0x750 mm/mempool.c:576
bio_put_percpu_cache block/bio.c:801 [inline]
bio_put+0x355/0x5b0 block/bio.c:820
bio_endio+0x710/0x860 block/bio.c:1651
blk_update_request+0x93e/0x15f0 block/blk-mq.c:989
blk_mq_end_request+0x4f/0x90 block/blk-mq.c:1151
blk_mq_complete_request block/blk-mq.c:1329 [inline]
blk_mq_complete_request+0x8b/0xb0 block/blk-mq.c:1326
nullb_complete_cmd drivers/block/null_blk/main.c:1402 [inline]
null_handle_cmd drivers/block/null_blk/main.c:1454 [inline]
null_queue_rq+0xb69/0xfd0 drivers/block/null_blk/main.c:1693
null_queue_rqs+0xe9/0x2f0 drivers/block/null_blk/main.c:1707
__blk_mq_flush_list block/blk-mq.c:2828 [inline]
__blk_mq_flush_list+0x97/0xc0 block/blk-mq.c:2824
blk_mq_dispatch_queue_requests+0x184/0x7b0 block/blk-mq.c:2873
blk_mq_flush_plug_list+0x1f2/0x600 block/blk-mq.c:2961
__blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1220
blk_finish_plug block/blk-core.c:1247 [inline]
blk_finish_plug+0x53/0xa0 block/blk-core.c:1244
blkdev_writepages+0xe9/0x140 block/fops.c:485
do_writepages+0x27a/0x600 mm/page-writeback.c:2634
filemap_fdatawrite_wbc mm/filemap.c:386 [inline]
filemap_fdatawrite_wbc+0x104/0x160 mm/filemap.c:376
__filemap_fdatawrite_range+0xb9/0x100 mm/filemap.c:419
filemap_write_and_wait_range mm/filemap.c:691 [inline]
filemap_write_and_wait_range+0xa3/0x130 mm/filemap.c:682
filemap_write_and_wait include/linux/pagemap.h:68 [inline]
sync_blockdev block/bdev.c:260 [inline]
sync_blockdev block/bdev.c:256 [inline]
bdev_release+0x4d3/0x6d0 block/bdev.c:1126
blkdev_release+0x15/0x20 block/fops.c:702
__fput+0x3ff/0xb70 fs/file_table.c:468
task_work_run+0x150/0x240 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x86f/0x2bf0 kernel/exit.c:961
do_group_exit+0xd3/0x2a0 kernel/exit.c:1102
get_signal+0x2673/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:40
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+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f82d878ebe9
RSP: 002b:00007f82d9656038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007f82d89c6090 RCX: 00007f82d878ebe9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f82d8811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f82d89c6128 R14: 00007f82d89c6090 R15: 00007ffe65a62258
task:syz-executor state:R running task stack:22552 pid:5852 tgid:5852 ppid:5850 task_flags:0x400140 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7145
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
copy_pte_range mm/memory.c:1201 [inline]
copy_pmd_range mm/memory.c:1261 [inline]
copy_pud_range mm/memory.c:1298 [inline]
copy_p4d_range mm/memory.c:1322 [inline]
copy_page_range+0x1f7d/0x5c80 mm/memory.c:1410
dup_mmap+0xe88/0x21d0 mm/mmap.c:1834
dup_mm kernel/fork.c:1485 [inline]
copy_mm kernel/fork.c:1537 [inline]
copy_process+0x4081/0x7690 kernel/fork.c:2175
kernel_clone+0xfc/0x930 kernel/fork.c:2605
__do_sys_clone+0xce/0x120 kernel/fork.c:2748
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f74dab85453
RSP: 002b:00007ffe4cb93bd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f74dab85453
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 000055557d3b77d0 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000035 R14: 00000000000c4de7 R15: 00007ffe4cb93d70
rcu: rcu_preempt kthread timer wakeup didn't happen for 10599 jiffies! g48109 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=72798
rcu: rcu_preempt kthread starved for 10605 jiffies! g48109 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28760 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 1299 Comm: aoe_tx0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 26 be 00 f6 48 89 df e8 0e 12 01 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 e5 0e f1 f5 65 8b 05 be ab 3f 08 85 c0 74 16 5b
RSP: 0018:ffffc900047af978 EFLAGS: 00000246
RAX: 0000000000000006 RBX: ffffffff9b115ba0 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8de522e8 RDI: ffffffff8c162d80
RBP: 0000000000000293 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff90ab6b97 R11: 0000000000000000 R12: ffffffff9b115ca8
R13: 0000000000000003 R14: 0000000000000001 R15: 0000000000000003
FS: 0000000000000000(0000) GS:ffff8881246b5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000404030 CR3: 000000005ccf4000 CR4: 00000000003526f0
Call Trace:
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
uart_port_unlock_irqrestore include/linux/serial_core.h:788 [inline]
uart_port_unlock_deref drivers/tty/serial/serial_core.c:91 [inline]
uart_port_unlock_deref drivers/tty/serial/serial_core.c:88 [inline]
uart_write+0x4c1/0xb30 drivers/tty/serial/serial_core.c:629
handle_tx+0x204/0x630 drivers/net/caif/caif_serial.c:222
__netdev_start_xmit include/linux/netdevice.h:5222 [inline]
netdev_start_xmit include/linux/netdevice.h:5231 [inline]
xmit_one net/core/dev.c:3839 [inline]
dev_hard_start_xmit+0x94/0x740 net/core/dev.c:3855
__dev_queue_xmit+0xa46/0x4490 net/core/dev.c:4725
dev_queue_xmit include/linux/netdevice.h:3361 [inline]
tx+0xcc/0x190 drivers/block/aoe/aoenet.c:62
kthread+0x1e4/0x3e0 drivers/block/aoe/aoecmd.c:1241
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
vkms_vblank_simulate: vblank timer overrun