rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6789/2:b..l rcu: (detected by 0, t=10503 jiffies, g=14705, q=6102 ncpus=2) task:syz.5.142 state:R running task stack:24600 pid:6789 tgid:6788 ppid:6046 task_flags:0x20400040 flags:0x00004006 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:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872 Code: a9 3e 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 52 85 13 0f 0f 82 74 02 00 00 8b 35 0a b7 13 0f 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 a9 a8 3e 12 0f 85 c7 02 00 00 48 83 c4 RSP: 0018:ffffc90002e369f0 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e5c1220 RCX: 00000000c639c71c RDX: 0000000000000000 RSI: ffffffff8de2ae00 RDI: ffffffff8c162900 RBP: 0000000000000002 R08: f501fefe41178ce3 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] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 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:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405 kmalloc_noprof include/linux/slab.h:905 [inline] slab_free_hook mm/slub.c:2369 [inline] slab_free mm/slub.c:4680 [inline] kmem_cache_free+0x142/0x4d0 mm/slub.c:4782 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+0x6bc/0x800 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_add_rq_to_plug+0x1ca/0x540 block/blk-mq.c:1390 blk_mq_submit_bio+0x1a6b/0x2a10 block/blk-mq.c:3212 __submit_bio+0x3cf/0x690 block/blk-core.c:635 __submit_bio_noacct_mq block/blk-core.c:722 [inline] submit_bio_noacct_nocheck+0x660/0xd30 block/blk-core.c:751 submit_bio_noacct+0xc20/0x1ed0 block/blk-core.c:874 __block_write_full_folio+0x735/0xe00 fs/buffer.c:1933 block_write_full_folio+0x341/0x400 fs/buffer.c:2753 blkdev_writepages+0xb8/0x140 block/fops.c:483 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:699 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x14d/0x240 kernel/task_work.c:227 get_signal+0x1d1/0x26d0 kernel/signal.c:2807 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: 0033:0x7f3da518ebe9 RSP: 002b:00007f3da5f28038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: 00000000046f0000 RBX: 00007f3da53b5fa0 RCX: 00007f3da518ebe9 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000005 RBP: 00007f3da5211e19 R08: 0000000000000000 R09: 0000000000000000 R10: 000400000000003f R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3da53b6038 R14: 00007f3da53b5fa0 R15: 00007ffd045fb0e8