====================================================== WARNING: possible circular locking dependency detected 6.12.0-syzkaller-08446-g228a1157fb9f #0 Not tainted ------------------------------------------------------ kswapd0/74 is trying to acquire lock: ffff888034bf1438 (&q->q_usage_counter(io)#37){++++}-{0:0}, at: __submit_bio+0x2c6/0x560 block/blk-core.c:629 but task is already holding lock: ffffffff8ea3eb40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6850 [inline] ffffffff8ea3eb40 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbf1/0x3700 mm/vmscan.c:7232 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (fs_reclaim){+.+.}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __fs_reclaim_acquire mm/page_alloc.c:3851 [inline] fs_reclaim_acquire+0x88/0x130 mm/page_alloc.c:3865 might_alloc include/linux/sched/mm.h:318 [inline] slab_pre_alloc_hook mm/slub.c:4036 [inline] slab_alloc_node mm/slub.c:4114 [inline] __do_kmalloc_node mm/slub.c:4263 [inline] __kmalloc_node_noprof+0xb0/0x440 mm/slub.c:4270 __kvmalloc_node_noprof+0x72/0x190 mm/util.c:658 sbitmap_init_node+0x2d4/0x670 lib/sbitmap.c:132 scsi_realloc_sdev_budget_map+0x2a7/0x460 drivers/scsi/scsi_scan.c:246 scsi_add_lun drivers/scsi/scsi_scan.c:1106 [inline] scsi_probe_and_add_lun+0x3173/0x4bd0 drivers/scsi/scsi_scan.c:1287 __scsi_add_device+0x228/0x2f0 drivers/scsi/scsi_scan.c:1622 ata_scsi_scan_host+0x236/0x740 drivers/ata/libata-scsi.c:4575 async_run_entry_fn+0xa8/0x420 kernel/async.c:129 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 (&q->q_usage_counter(io)#37){++++}-{0:0}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 bio_queue_enter block/blk.h:75 [inline] blk_mq_submit_bio+0x1536/0x23a0 block/blk-mq.c:3092 __submit_bio+0x2c6/0x560 block/blk-core.c:629 __submit_bio_noacct_mq block/blk-core.c:710 [inline] submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:739 swap_writepage_bdev_async mm/page_io.c:449 [inline] __swap_writepage+0x5fc/0x1400 mm/page_io.c:472 swap_writepage+0x85d/0xfa0 mm/page_io.c:288 pageout mm/vmscan.c:689 [inline] shrink_folio_list+0x3c0e/0x8cc0 mm/vmscan.c:1367 evict_folios+0x549b/0x7b50 mm/vmscan.c:4589 try_to_shrink_lruvec+0x9ab/0xbb0 mm/vmscan.c:4784 shrink_one+0x3b9/0x850 mm/vmscan.c:4822 shrink_many mm/vmscan.c:4885 [inline] lru_gen_shrink_node mm/vmscan.c:4963 [inline] shrink_node+0x3789/0x3e10 mm/vmscan.c:5943 kswapd_shrink_node mm/vmscan.c:6771 [inline] balance_pgdat mm/vmscan.c:6963 [inline] kswapd+0x1ca9/0x3700 mm/vmscan.c:7232 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&q->q_usage_counter(io)#37); lock(fs_reclaim); rlock(&q->q_usage_counter(io)#37); *** DEADLOCK *** 1 lock held by kswapd0/74: #0: ffffffff8ea3eb40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6850 [inline] #0: ffffffff8ea3eb40 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbf1/0x3700 mm/vmscan.c:7232 stack backtrace: CPU: 0 UID: 0 PID: 74 Comm: kswapd0 Not tainted 6.12.0-syzkaller-08446-g228a1157fb9f #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 bio_queue_enter block/blk.h:75 [inline] blk_mq_submit_bio+0x1536/0x23a0 block/blk-mq.c:3092 __submit_bio+0x2c6/0x560 block/blk-core.c:629 __submit_bio_noacct_mq block/blk-core.c:710 [inline] submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:739 swap_writepage_bdev_async mm/page_io.c:449 [inline] __swap_writepage+0x5fc/0x1400 mm/page_io.c:472 swap_writepage+0x85d/0xfa0 mm/page_io.c:288 pageout mm/vmscan.c:689 [inline] shrink_folio_list+0x3c0e/0x8cc0 mm/vmscan.c:1367 evict_folios+0x549b/0x7b50 mm/vmscan.c:4589 try_to_shrink_lruvec+0x9ab/0xbb0 mm/vmscan.c:4784 shrink_one+0x3b9/0x850 mm/vmscan.c:4822 shrink_many mm/vmscan.c:4885 [inline] lru_gen_shrink_node mm/vmscan.c:4963 [inline] shrink_node+0x3789/0x3e10 mm/vmscan.c:5943 kswapd_shrink_node mm/vmscan.c:6771 [inline] balance_pgdat mm/vmscan.c:6963 [inline] kswapd+0x1ca9/0x3700 mm/vmscan.c:7232 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244