====================================================== WARNING: possible circular locking dependency detected 6.14.0-rc7-syzkaller-00205-g586de92313fc #0 Not tainted ------------------------------------------------------ syz.0.27/6087 is trying to acquire lock: ffff8881070cb310 (set->srcu){.+.+}-{0:0}, at: srcu_lock_sync include/linux/srcu.h:176 [inline] ffff8881070cb310 (set->srcu){.+.+}-{0:0}, at: __synchronize_srcu+0x99/0x2a0 kernel/rcu/srcutree.c:1418 but task is already holding lock: ffff888025b533c8 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_mq_elv_switch_none block/blk-mq.c:4937 [inline] ffff888025b533c8 (&q->sysfs_lock){+.+.}-{4:4}, at: __blk_mq_update_nr_hw_queues block/blk-mq.c:5018 [inline] ffff888025b533c8 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_mq_update_nr_hw_queues+0x4a7/0x1360 block/blk-mq.c:5070 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #7 (&q->sysfs_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 blk_mq_elv_switch_none block/blk-mq.c:4937 [inline] __blk_mq_update_nr_hw_queues block/blk-mq.c:5018 [inline] blk_mq_update_nr_hw_queues+0x4a7/0x1360 block/blk-mq.c:5070 nbd_start_device+0x172/0xcd0 drivers/block/nbd.c:1476 nbd_start_device_ioctl drivers/block/nbd.c:1527 [inline] __nbd_ioctl drivers/block/nbd.c:1602 [inline] nbd_ioctl+0x21a/0xd60 drivers/block/nbd.c:1642 blkdev_ioctl+0x276/0x6d0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #6 (&q->q_usage_counter(io)#49){++++}-{0:0}: bio_queue_enter block/blk.h:78 [inline] blk_mq_submit_bio+0x20f5/0x2610 block/blk-mq.c:3091 __submit_bio+0x3d1/0x690 block/blk-core.c:628 __submit_bio_noacct_mq block/blk-core.c:715 [inline] submit_bio_noacct_nocheck+0x698/0xd70 block/blk-core.c:744 submit_bio_noacct+0x50d/0x1ec0 block/blk-core.c:867 submit_bh fs/buffer.c:2819 [inline] block_read_full_folio+0x812/0xa50 fs/buffer.c:2446 filemap_read_folio+0xc6/0x2a0 mm/filemap.c:2400 filemap_update_page mm/filemap.c:2484 [inline] filemap_get_pages+0x10ad/0x1c30 mm/filemap.c:2612 filemap_read+0x3c5/0xe70 mm/filemap.c:2701 blkdev_read_iter+0x187/0x4b0 block/fops.c:796 new_sync_read fs/read_write.c:484 [inline] vfs_read+0x886/0xbf0 fs/read_write.c:565 ksys_read+0x12b/0x250 fs/read_write.c:708 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #5 (mapping.invalidate_lock#2){++++}-{4:4}: down_read+0x9a/0x330 kernel/locking/rwsem.c:1524 filemap_invalidate_lock_shared include/linux/fs.h:932 [inline] filemap_fault+0x2e0/0x2820 mm/filemap.c:3390 __do_fault+0x10a/0x490 mm/memory.c:4989 do_shared_fault mm/memory.c:5473 [inline] do_fault mm/memory.c:5547 [inline] do_pte_missing+0x1a8/0x3e10 mm/memory.c:4059 handle_pte_fault mm/memory.c:5888 [inline] __handle_mm_fault+0x103c/0x2a40 mm/memory.c:6031 handle_mm_fault+0x3fa/0xaa0 mm/memory.c:6200 faultin_page mm/gup.c:1196 [inline] __get_user_pages+0x773/0x36f0 mm/gup.c:1491 __get_user_pages_locked mm/gup.c:1757 [inline] faultin_page_range+0x24a/0x980 mm/gup.c:1981 madvise_populate mm/madvise.c:965 [inline] do_madvise+0x553/0x7c0 mm/madvise.c:1695 __do_sys_madvise mm/madvise.c:1714 [inline] __se_sys_madvise mm/madvise.c:1712 [inline] __x64_sys_madvise+0xa9/0x110 mm/madvise.c:1712 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #4 (&mm->mmap_lock){++++}-{4:4}: __might_fault mm/memory.c:6839 [inline] __might_fault+0x11b/0x190 mm/memory.c:6832 _copy_from_iter+0x1c4/0x1560 lib/iov_iter.c:259 copy_from_iter include/linux/uio.h:228 [inline] copy_from_iter_full include/linux/uio.h:245 [inline] skb_do_copy_data_nocache include/net/sock.h:2197 [inline] skb_copy_to_page_nocache include/net/sock.h:2223 [inline] tcp_sendmsg_locked+0x1979/0x37c0 net/ipv4/tcp.c:1222 tcp_sendmsg+0x2e/0x50 net/ipv4/tcp.c:1358 inet_sendmsg+0xb9/0x140 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:733 [inline] sock_write_iter+0x4ac/0x5b0 net/socket.c:1137 new_sync_write fs/read_write.c:586 [inline] vfs_write+0x5ae/0x1150 fs/read_write.c:679 ksys_write+0x207/0x250 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (sk_lock-AF_INET){+.+.}-{0:0}: lock_sock_nested+0x3a/0xf0 net/core/sock.c:3662 lock_sock include/net/sock.h:1624 [inline] inet_autobind+0x1a/0x1a0 net/ipv4/af_inet.c:178 inet_send_prepare+0x317/0x530 net/ipv4/af_inet.c:837 inet_sendmsg+0x43/0x140 net/ipv4/af_inet.c:848 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:733 [inline] sock_sendmsg+0x389/0x490 net/socket.c:756 __sock_xmit+0x1e8/0x4f0 drivers/block/nbd.c:574 sock_xmit drivers/block/nbd.c:602 [inline] nbd_send_cmd+0x8ec/0x1c90 drivers/block/nbd.c:712 nbd_handle_cmd drivers/block/nbd.c:1174 [inline] nbd_queue_rq+0x941/0x1220 drivers/block/nbd.c:1204 blk_mq_dispatch_rq_list+0x443/0x1dc0 block/blk-mq.c:2120 __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+0xcdf/0x1620 block/blk-mq-sched.c:309 blk_mq_sched_dispatch_requests+0xd8/0x1b0 block/blk-mq-sched.c:331 blk_mq_run_hw_queue+0x239/0x670 block/blk-mq.c:2354 blk_mq_dispatch_plug_list block/blk-mq.c:2866 [inline] blk_mq_flush_plug_list+0x673/0x1c60 block/blk-mq.c:2917 __blk_flush_plug+0x2c5/0x4b0 block/blk-core.c:1213 blk_finish_plug block/blk-core.c:1240 [inline] blk_finish_plug block/blk-core.c:1237 [inline] __submit_bio+0x547/0x690 block/blk-core.c:642 __submit_bio_noacct_mq block/blk-core.c:715 [inline] submit_bio_noacct_nocheck+0x698/0xd70 block/blk-core.c:744 submit_bio_noacct+0x50d/0x1ec0 block/blk-core.c:867 submit_bh fs/buffer.c:2819 [inline] __bread_slow fs/buffer.c:1264 [inline] __bread_gfp+0x189/0x340 fs/buffer.c:1488 sb_bread include/linux/buffer_head.h:346 [inline] udf_read_tagged+0xae/0x740 fs/udf/misc.c:199 udf_check_anchor_block+0x8a/0x4b0 fs/udf/super.c:1903 udf_scan_anchors fs/udf/super.c:1964 [inline] udf_load_vrs+0x577/0x1050 fs/udf/super.c:2024 udf_fill_super+0x792/0x1df0 fs/udf/super.c:2192 get_tree_bdev_flags+0x38b/0x620 fs/super.c:1636 vfs_get_tree+0x8b/0x340 fs/super.c:1814 do_new_mount fs/namespace.c:3560 [inline] path_mount+0x14e6/0x1f10 fs/namespace.c:3887 do_mount fs/namespace.c:3900 [inline] __do_sys_mount fs/namespace.c:4111 [inline] __se_sys_mount fs/namespace.c:4088 [inline] __x64_sys_mount+0x28f/0x310 fs/namespace.c:4088 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&nsock->tx_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 nbd_handle_cmd drivers/block/nbd.c:1140 [inline] nbd_queue_rq+0x424/0x1220 drivers/block/nbd.c:1204 blk_mq_dispatch_rq_list+0x443/0x1dc0 block/blk-mq.c:2120 __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+0xcdf/0x1620 block/blk-mq-sched.c:309 blk_mq_sched_dispatch_requests+0xd8/0x1b0 block/blk-mq-sched.c:331 blk_mq_run_hw_queue+0x239/0x670 block/blk-mq.c:2354 blk_mq_dispatch_plug_list block/blk-mq.c:2866 [inline] blk_mq_flush_plug_list+0x673/0x1c60 block/blk-mq.c:2917 __blk_flush_plug+0x2c5/0x4b0 block/blk-core.c:1213 blk_finish_plug block/blk-core.c:1240 [inline] blk_finish_plug block/blk-core.c:1237 [inline] __submit_bio+0x547/0x690 block/blk-core.c:642 __submit_bio_noacct_mq block/blk-core.c:715 [inline] submit_bio_noacct_nocheck+0x698/0xd70 block/blk-core.c:744 submit_bio_noacct+0x50d/0x1ec0 block/blk-core.c:867 submit_bh fs/buffer.c:2819 [inline] __bread_slow fs/buffer.c:1264 [inline] __bread_gfp+0x189/0x340 fs/buffer.c:1488 sb_bread include/linux/buffer_head.h:346 [inline] udf_read_tagged+0xae/0x740 fs/udf/misc.c:199 udf_check_anchor_block+0x8a/0x4b0 fs/udf/super.c:1903 udf_scan_anchors fs/udf/super.c:1964 [inline] udf_load_vrs+0x577/0x1050 fs/udf/super.c:2024 udf_fill_super+0x792/0x1df0 fs/udf/super.c:2192 get_tree_bdev_flags+0x38b/0x620 fs/super.c:1636 vfs_get_tree+0x8b/0x340 fs/super.c:1814 do_new_mount fs/namespace.c:3560 [inline] path_mount+0x14e6/0x1f10 fs/namespace.c:3887 do_mount fs/namespace.c:3900 [inline] __do_sys_mount fs/namespace.c:4111 [inline] __se_sys_mount fs/namespace.c:4088 [inline] __x64_sys_mount+0x28f/0x310 fs/namespace.c:4088 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&cmd->lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 nbd_queue_rq+0xbe/0x1220 drivers/block/nbd.c:1196 blk_mq_dispatch_rq_list+0x443/0x1dc0 block/blk-mq.c:2120 __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+0xcdf/0x1620 block/blk-mq-sched.c:309 blk_mq_sched_dispatch_requests+0xd8/0x1b0 block/blk-mq-sched.c:331 blk_mq_run_hw_queue+0x239/0x670 block/blk-mq.c:2354 blk_mq_dispatch_plug_list block/blk-mq.c:2866 [inline] blk_mq_flush_plug_list+0x673/0x1c60 block/blk-mq.c:2917 __blk_flush_plug+0x2c5/0x4b0 block/blk-core.c:1213 blk_finish_plug block/blk-core.c:1240 [inline] blk_finish_plug block/blk-core.c:1237 [inline] __submit_bio+0x547/0x690 block/blk-core.c:642 __submit_bio_noacct_mq block/blk-core.c:715 [inline] submit_bio_noacct_nocheck+0x698/0xd70 block/blk-core.c:744 submit_bio_noacct+0x50d/0x1ec0 block/blk-core.c:867 submit_bh fs/buffer.c:2819 [inline] __bread_slow fs/buffer.c:1264 [inline] __bread_gfp+0x189/0x340 fs/buffer.c:1488 sb_bread include/linux/buffer_head.h:346 [inline] udf_read_tagged+0xae/0x740 fs/udf/misc.c:199 udf_check_anchor_block+0x8a/0x4b0 fs/udf/super.c:1903 udf_scan_anchors fs/udf/super.c:1964 [inline] udf_load_vrs+0x577/0x1050 fs/udf/super.c:2024 udf_fill_super+0x792/0x1df0 fs/udf/super.c:2192 get_tree_bdev_flags+0x38b/0x620 fs/super.c:1636 vfs_get_tree+0x8b/0x340 fs/super.c:1814 do_new_mount fs/namespace.c:3560 [inline] path_mount+0x14e6/0x1f10 fs/namespace.c:3887 do_mount fs/namespace.c:3900 [inline] __do_sys_mount fs/namespace.c:4111 [inline] __se_sys_mount fs/namespace.c:4088 [inline] __x64_sys_mount+0x28f/0x310 fs/namespace.c:4088 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (set->srcu){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain kernel/locking/lockdep.c:3906 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228 lock_sync+0xf5/0x190 kernel/locking/lockdep.c:5899 srcu_lock_sync include/linux/srcu.h:176 [inline] __synchronize_srcu+0xa9/0x2a0 kernel/rcu/srcutree.c:1418 blk_mq_wait_quiesce_done block/blk-mq.c:293 [inline] blk_mq_wait_quiesce_done block/blk-mq.c:290 [inline] blk_mq_quiesce_queue block/blk-mq.c:313 [inline] blk_mq_quiesce_queue+0x149/0x1b0 block/blk-mq.c:308 elevator_disable+0xe9/0x570 block/elevator.c:661 blk_mq_elv_switch_none block/blk-mq.c:4951 [inline] __blk_mq_update_nr_hw_queues block/blk-mq.c:5018 [inline] blk_mq_update_nr_hw_queues+0x41c/0x1360 block/blk-mq.c:5070 nbd_start_device+0x172/0xcd0 drivers/block/nbd.c:1476 nbd_start_device_ioctl drivers/block/nbd.c:1527 [inline] __nbd_ioctl drivers/block/nbd.c:1602 [inline] nbd_ioctl+0x21a/0xd60 drivers/block/nbd.c:1642 blkdev_ioctl+0x276/0x6d0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: set->srcu --> &q->q_usage_counter(io)#49 --> &q->sysfs_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&q->sysfs_lock); lock(&q->q_usage_counter(io)#49); lock(&q->sysfs_lock); sync(set->srcu); *** DEADLOCK *** 5 locks held by syz.0.27/6087: #0: ffff888025b7b198 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x151/0xd60 drivers/block/nbd.c:1635 #1: ffff888025b7b0d8 (&set->tag_list_lock){+.+.}-{4:4}, at: blk_mq_update_nr_hw_queues+0x8f/0x1360 block/blk-mq.c:5069 #2: ffff888025b52e98 (&q->q_usage_counter(io)#49){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave block/blk-mq.c:215 [inline] #2: ffff888025b52e98 (&q->q_usage_counter(io)#49){++++}-{0:0}, at: __blk_mq_update_nr_hw_queues block/blk-mq.c:5010 [inline] #2: ffff888025b52e98 (&q->q_usage_counter(io)#49){++++}-{0:0}, at: blk_mq_update_nr_hw_queues+0x264/0x1360 block/blk-mq.c:5070 #3: ffff888025b52ed0 (&q->q_usage_counter(queue)#33){+.+.}-{0:0}, at: blk_mq_freeze_queue_nomemsave block/blk-mq.c:215 [inline] #3: ffff888025b52ed0 (&q->q_usage_counter(queue)#33){+.+.}-{0:0}, at: __blk_mq_update_nr_hw_queues block/blk-mq.c:5010 [inline] #3: ffff888025b52ed0 (&q->q_usage_counter(queue)#33){+.+.}-{0:0}, at: blk_mq_update_nr_hw_queues+0x264/0x1360 block/blk-mq.c:5070 #4: ffff888025b533c8 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_mq_elv_switch_none block/blk-mq.c:4937 [inline] #4: ffff888025b533c8 (&q->sysfs_lock){+.+.}-{4:4}, at: __blk_mq_update_nr_hw_queues block/blk-mq.c:5018 [inline] #4: ffff888025b533c8 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_mq_update_nr_hw_queues+0x4a7/0x1360 block/blk-mq.c:5070 stack backtrace: CPU: 3 UID: 0 PID: 6087 Comm: syz.0.27 Not tainted 6.14.0-rc7-syzkaller-00205-g586de92313fc #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+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x490/0x760 kernel/locking/lockdep.c:2076 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2208 check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain kernel/locking/lockdep.c:3906 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228 lock_sync+0xf5/0x190 kernel/locking/lockdep.c:5899 srcu_lock_sync include/linux/srcu.h:176 [inline] __synchronize_srcu+0xa9/0x2a0 kernel/rcu/srcutree.c:1418 blk_mq_wait_quiesce_done block/blk-mq.c:293 [inline] blk_mq_wait_quiesce_done block/blk-mq.c:290 [inline] blk_mq_quiesce_queue block/blk-mq.c:313 [inline] blk_mq_quiesce_queue+0x149/0x1b0 block/blk-mq.c:308 elevator_disable+0xe9/0x570 block/elevator.c:661 blk_mq_elv_switch_none block/blk-mq.c:4951 [inline] __blk_mq_update_nr_hw_queues block/blk-mq.c:5018 [inline] blk_mq_update_nr_hw_queues+0x41c/0x1360 block/blk-mq.c:5070 nbd_start_device+0x172/0xcd0 drivers/block/nbd.c:1476 nbd_start_device_ioctl drivers/block/nbd.c:1527 [inline] __nbd_ioctl drivers/block/nbd.c:1602 [inline] nbd_ioctl+0x21a/0xd60 drivers/block/nbd.c:1642 blkdev_ioctl+0x276/0x6d0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f55dad8d169 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:00007f55dabf9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f55dafa5fa0 RCX: 00007f55dad8d169 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f55dae0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f55dafa5fa0 R15: 00007fff83bc8538 block nbd0: shutting down sockets