====================================================== WARNING: possible circular locking dependency detected 6.13.0-rc4-syzkaller-00078-g059dd502b263 #0 Not tainted ------------------------------------------------------ syz.4.3470/20824 is trying to acquire lock: ffff888143b536c0 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_mq_elv_switch_none block/blk-mq.c:4932 [inline] ffff888143b536c0 (&q->sysfs_lock){+.+.}-{4:4}, at: __blk_mq_update_nr_hw_queues block/blk-mq.c:5010 [inline] ffff888143b536c0 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_mq_update_nr_hw_queues+0x3fa/0x1ae0 block/blk-mq.c:5070 but task is already holding lock: ffff888143b53190 (&q->q_usage_counter(io)#53){++++}-{0:0}, at: nbd_start_device+0x16c/0xaa0 drivers/block/nbd.c:1413 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #7 (&q->q_usage_counter(io)#53){++++}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 bio_queue_enter block/blk.h:75 [inline] blk_mq_submit_bio+0x1536/0x2390 block/blk-mq.c:3090 __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 submit_bh fs/buffer.c:2819 [inline] block_read_full_folio+0x9b3/0xae0 fs/buffer.c:2446 filemap_read_folio+0x14a/0x3b0 mm/filemap.c:2366 filemap_update_page mm/filemap.c:2450 [inline] filemap_get_pages+0x18ca/0x2080 mm/filemap.c:2571 filemap_read+0x452/0xf50 mm/filemap.c:2646 blkdev_read_iter+0x2d8/0x430 block/fops.c:770 new_sync_read fs/read_write.c:484 [inline] vfs_read+0x993/0xb70 fs/read_write.c:565 ksys_read+0x18f/0x2b0 fs/read_write.c:708 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #6 (mapping.invalidate_lock#2){++++}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1524 filemap_invalidate_lock_shared include/linux/fs.h:873 [inline] filemap_fault+0xb3e/0x1490 mm/filemap.c:3351 __do_fault+0x137/0x390 mm/memory.c:4907 do_shared_fault mm/memory.c:5386 [inline] do_fault mm/memory.c:5460 [inline] do_pte_missing mm/memory.c:3979 [inline] handle_pte_fault+0xfcf/0x5ed0 mm/memory.c:5801 __handle_mm_fault mm/memory.c:5944 [inline] handle_mm_fault+0x1106/0x1bb0 mm/memory.c:6112 do_user_addr_fault arch/x86/mm/fault.c:1389 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x2b9/0x8b0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline] _inline_copy_to_user include/linux/uaccess.h:197 [inline] _copy_to_user+0x86/0xb0 lib/usercopy.c:26 copy_to_user include/linux/uaccess.h:225 [inline] cec_dqevent drivers/media/cec/core/cec-api.c:346 [inline] cec_ioctl+0x17d4/0x3380 drivers/media/cec/core/cec-api.c:540 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf7/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #5 (&mm->mmap_lock){++++}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __might_fault+0xc6/0x120 mm/memory.c:6751 _copy_from_iter+0x100/0x1c20 lib/iov_iter.c:259 copy_from_iter include/linux/uio.h:219 [inline] copy_from_iter_full include/linux/uio.h:236 [inline] skb_do_copy_data_nocache include/net/sock.h:2193 [inline] skb_copy_to_page_nocache include/net/sock.h:2219 [inline] tcp_sendmsg_locked+0x18a5/0x4f30 net/ipv4/tcp.c:1222 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1358 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:726 sock_write_iter+0x2d7/0x3f0 net/socket.c:1147 new_sync_write fs/read_write.c:586 [inline] vfs_write+0xaed/0xd30 fs/read_write.c:679 ksys_write+0x18f/0x2b0 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #4 (sk_lock-AF_INET){+.+.}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 lock_sock_nested+0x48/0x100 net/core/sock.c:3622 lock_sock include/net/sock.h:1623 [inline] inet_shutdown+0x6d/0x390 net/ipv4/af_inet.c:905 nbd_mark_nsock_dead+0x2e3/0x560 drivers/block/nbd.c:314 sock_shutdown+0x165/0x280 drivers/block/nbd.c:420 nbd_start_device_ioctl drivers/block/nbd.c:1474 [inline] __nbd_ioctl drivers/block/nbd.c:1539 [inline] nbd_ioctl+0xac7/0xf40 drivers/block/nbd.c:1579 blkdev_ioctl+0x57f/0x6a0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf7/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (&nsock->tx_lock){+.+.}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735 nbd_handle_cmd drivers/block/nbd.c:1079 [inline] nbd_queue_rq+0x29c/0x2ef0 drivers/block/nbd.c:1143 blk_mq_dispatch_rq_list+0xad5/0x19d0 block/blk-mq.c:2118 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:170 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:184 [inline] __blk_mq_sched_dispatch_requests+0xb8a/0x1840 block/blk-mq-sched.c:309 blk_mq_sched_dispatch_requests+0xd6/0x190 block/blk-mq-sched.c:331 blk_mq_run_hw_queue+0x354/0x500 block/blk-mq.c:2352 blk_mq_flush_plug_list+0x118e/0x1870 block/blk-mq.c:2913 __blk_flush_plug+0x420/0x500 block/blk-core.c:1213 blk_finish_plug block/blk-core.c:1240 [inline] __submit_bio+0x46a/0x560 block/blk-core.c:637 __submit_bio_noacct_mq block/blk-core.c:710 [inline] submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:739 submit_bh fs/buffer.c:2819 [inline] block_read_full_folio+0x9b3/0xae0 fs/buffer.c:2446 filemap_read_folio+0x14a/0x3b0 mm/filemap.c:2366 do_read_cache_folio+0x373/0x5b0 mm/filemap.c:3826 read_mapping_folio include/linux/pagemap.h:1011 [inline] read_part_sector+0xb3/0x260 block/partitions/core.c:722 adfspart_check_ICS+0xd9/0x9a0 block/partitions/acorn.c:360 check_partition block/partitions/core.c:141 [inline] blk_add_partitions block/partitions/core.c:589 [inline] bdev_disk_changed+0x72e/0x13f0 block/partitions/core.c:693 blkdev_get_whole+0x2d2/0x450 block/bdev.c:706 bdev_open+0x2d4/0xc50 block/bdev.c:915 blkdev_open+0x389/0x4f0 block/fops.c:627 do_dentry_open+0xbe3/0x1b70 fs/open.c:945 vfs_open+0x3e/0x330 fs/open.c:1075 do_open fs/namei.c:3828 [inline] path_openat+0x2c84/0x3590 fs/namei.c:3987 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_openat fs/open.c:1433 [inline] __se_sys_openat fs/open.c:1428 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1428 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&cmd->lock){+.+.}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735 nbd_queue_rq+0xfe/0x2ef0 drivers/block/nbd.c:1135 blk_mq_dispatch_rq_list+0xad5/0x19d0 block/blk-mq.c:2118 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:170 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:184 [inline] __blk_mq_sched_dispatch_requests+0xb8a/0x1840 block/blk-mq-sched.c:309 blk_mq_sched_dispatch_requests+0xd6/0x190 block/blk-mq-sched.c:331 blk_mq_run_hw_queue+0x354/0x500 block/blk-mq.c:2352 blk_mq_flush_plug_list+0x118e/0x1870 block/blk-mq.c:2913 __blk_flush_plug+0x420/0x500 block/blk-core.c:1213 blk_finish_plug block/blk-core.c:1240 [inline] __submit_bio+0x46a/0x560 block/blk-core.c:637 __submit_bio_noacct_mq block/blk-core.c:710 [inline] submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:739 submit_bh fs/buffer.c:2819 [inline] block_read_full_folio+0x9b3/0xae0 fs/buffer.c:2446 filemap_read_folio+0x14a/0x3b0 mm/filemap.c:2366 do_read_cache_folio+0x373/0x5b0 mm/filemap.c:3826 read_mapping_folio include/linux/pagemap.h:1011 [inline] read_part_sector+0xb3/0x260 block/partitions/core.c:722 adfspart_check_ICS+0xd9/0x9a0 block/partitions/acorn.c:360 check_partition block/partitions/core.c:141 [inline] blk_add_partitions block/partitions/core.c:589 [inline] bdev_disk_changed+0x72e/0x13f0 block/partitions/core.c:693 blkdev_get_whole+0x2d2/0x450 block/bdev.c:706 bdev_open+0x2d4/0xc50 block/bdev.c:915 blkdev_open+0x389/0x4f0 block/fops.c:627 do_dentry_open+0xbe3/0x1b70 fs/open.c:945 vfs_open+0x3e/0x330 fs/open.c:1075 do_open fs/namei.c:3828 [inline] path_openat+0x2c84/0x3590 fs/namei.c:3987 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_openat fs/open.c:1433 [inline] __se_sys_openat fs/open.c:1428 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1428 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (set->srcu){.+.+}-{0:0}: lock_sync+0x18b/0x310 kernel/locking/lockdep.c:5897 srcu_lock_sync include/linux/srcu.h:170 [inline] __synchronize_srcu+0xb1/0x400 kernel/rcu/srcutree.c:1418 elevator_disable+0x8c/0x3f0 block/elevator.c:671 blk_mq_elv_switch_none block/blk-mq.c:4946 [inline] __blk_mq_update_nr_hw_queues block/blk-mq.c:5010 [inline] blk_mq_update_nr_hw_queues+0x646/0x1ae0 block/blk-mq.c:5070 nbd_start_device+0x16c/0xaa0 drivers/block/nbd.c:1413 nbd_start_device_ioctl drivers/block/nbd.c:1464 [inline] __nbd_ioctl drivers/block/nbd.c:1539 [inline] nbd_ioctl+0x5dc/0xf40 drivers/block/nbd.c:1579 blkdev_ioctl+0x57f/0x6a0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf7/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&q->sysfs_lock){+.+.}-{4:4}: 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 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735 blk_mq_elv_switch_none block/blk-mq.c:4932 [inline] __blk_mq_update_nr_hw_queues block/blk-mq.c:5010 [inline] blk_mq_update_nr_hw_queues+0x3fa/0x1ae0 block/blk-mq.c:5070 nbd_start_device+0x16c/0xaa0 drivers/block/nbd.c:1413 nbd_start_device_ioctl drivers/block/nbd.c:1464 [inline] __nbd_ioctl drivers/block/nbd.c:1539 [inline] nbd_ioctl+0x5dc/0xf40 drivers/block/nbd.c:1579 blkdev_ioctl+0x57f/0x6a0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf7/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &q->sysfs_lock --> mapping.invalidate_lock#2 --> &q->q_usage_counter(io)#53 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&q->q_usage_counter(io)#53); lock(mapping.invalidate_lock#2); lock(&q->q_usage_counter(io)#53); lock(&q->sysfs_lock); *** DEADLOCK *** 4 locks held by syz.4.3470/20824: #0: ffff88802568c198 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x13c/0xf40 drivers/block/nbd.c:1572 #1: ffff88802568c0d8 (&set->tag_list_lock){+.+.}-{4:4}, at: blk_mq_update_nr_hw_queues+0xc2/0x1ae0 block/blk-mq.c:5069 #2: ffff888143b53190 (&q->q_usage_counter(io)#53){++++}-{0:0}, at: nbd_start_device+0x16c/0xaa0 drivers/block/nbd.c:1413 #3: ffff888143b531c8 (&q->q_usage_counter(queue)#37){+.+.}-{0:0}, at: nbd_start_device+0x16c/0xaa0 drivers/block/nbd.c:1413 stack backtrace: CPU: 1 UID: 0 PID: 20824 Comm: syz.4.3470 Not tainted 6.13.0-rc4-syzkaller-00078-g059dd502b263 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 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 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735 blk_mq_elv_switch_none block/blk-mq.c:4932 [inline] __blk_mq_update_nr_hw_queues block/blk-mq.c:5010 [inline] blk_mq_update_nr_hw_queues+0x3fa/0x1ae0 block/blk-mq.c:5070 nbd_start_device+0x16c/0xaa0 drivers/block/nbd.c:1413 nbd_start_device_ioctl drivers/block/nbd.c:1464 [inline] __nbd_ioctl drivers/block/nbd.c:1539 [inline] nbd_ioctl+0x5dc/0xf40 drivers/block/nbd.c:1579 blkdev_ioctl+0x57f/0x6a0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf7/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7a16b85d29 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7a17a39038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f7a16d76080 RCX: 00007f7a16b85d29 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f7a16c01b08 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f7a16d76080 R15: 00007ffe37520838 block nbd4: shutting down sockets