Hello. This is a sudden splash I've got while just using my workstation: ================================================================== BUG: KFENCE: use-after-free read in bfq_exit_icq_bfqq+0x132/0x270 Use-after-free read at 0x00000000e57c579c (in kfence-#173): bfq_exit_icq_bfqq+0x132/0x270 bfq_exit_icq+0x5e/0x80 exit_io_context+0x88/0xb0 do_exit+0x66c/0xb80 kthread_exit+0x29/0x30 kthread+0xbd/0x110 ret_from_fork+0x22/0x30 kfence-#173: 0x000000005d7be631-0x000000006ad0b684, size=568, cache=bfq_queue allocated by task 40147 on cpu 16 at 13975.114285s: bfq_get_queue+0xdf/0x4e0 bfq_get_bfqq_handle_split+0x75/0x170 bfq_insert_requests+0x832/0x2580 blk_mq_sched_insert_requests+0x63/0x150 blk_mq_flush_plug_list+0x122/0x360 __blk_flush_plug+0x106/0x160 blk_finish_plug+0x29/0x40 dm_bufio_prefetch+0x108/0x4d0 [dm_bufio] dm_tm_issue_prefetches+0x44/0x70 [dm_persistent_data] dm_pool_issue_prefetches+0x39/0x43 [dm_thin_pool] do_worker+0x4c/0xd60 [dm_thin_pool] process_one_work+0x258/0x410 worker_thread+0x55/0x4c0 kthread+0xde/0x110 ret_from_fork+0x22/0x30 freed by task 40147 on cpu 20 at 14500.096700s: bfq_put_queue+0x185/0x2d0 bfq_exit_icq_bfqq+0x129/0x270 bfq_exit_icq+0x5e/0x80 exit_io_context+0x88/0xb0 do_exit+0x66c/0xb80 kthread_exit+0x29/0x30 kthread+0xbd/0x110 ret_from_fork+0x22/0x30 CPU: 20 PID: 40147 Comm: kworker/dying Tainted: G W 6.1.0-pf2 #1 ff5dbde5ea280110a73397797e059b8558cda111 Hardware name: ASUS System Product Name/Pro WS X570-ACE, BIOS 4304 12/12/2022 ================================================================== I'm using v6.1.2, never experienced this before and cannot reproduce it at will. This kernel does not have any extra patches for the block layer on top of v6.1.2. In case you know what's going on, please let me know. Thanks! -- Oleksandr Natalenko (post-factum)