netlink: 16 bytes leftover after parsing attributes in process `syz-executor.3'. block nbd1: shutting down sockets nbd: must specify at least one socket IPVS: ftp: loaded support on port[0] = 21 ====================================================== WARNING: possible circular locking dependency detected 4.19.211-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/21935 is trying to acquire lock: 00000000430aa70a ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: flush_workqueue+0xe8/0x13e0 kernel/workqueue.c:2658 but task is already holding lock: 000000001464e3c9 (&nbd->config_lock){+.+.}, at: refcount_dec_and_mutex_lock lib/refcount.c:311 [inline] 000000001464e3c9 (&nbd->config_lock){+.+.}, at: refcount_dec_and_mutex_lock+0x4a/0x80 lib/refcount.c:306 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #10 (&nbd->config_lock){+.+.}: nbd_open+0x2e2/0x6f0 drivers/block/nbd.c:1428 __blkdev_get+0x372/0x1480 fs/block_dev.c:1494 blkdev_get+0xb0/0x940 fs/block_dev.c:1627 blkdev_open+0x202/0x290 fs/block_dev.c:1788 do_dentry_open+0x4aa/0x1160 fs/open.c:796 do_last fs/namei.c:3421 [inline] path_openat+0x793/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_sys_open+0x3b3/0x520 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #9 (nbd_index_mutex){+.+.}: nbd_open+0x73/0x6f0 drivers/block/nbd.c:1415 __blkdev_get+0x372/0x1480 fs/block_dev.c:1494 blkdev_get+0xb0/0x940 fs/block_dev.c:1627 blkdev_open+0x202/0x290 fs/block_dev.c:1788 do_dentry_open+0x4aa/0x1160 fs/open.c:796 do_last fs/namei.c:3421 [inline] path_openat+0x793/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_sys_open+0x3b3/0x520 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #8 (&bdev->bd_mutex){+.+.}: blkdev_put+0x30/0x520 fs/block_dev.c:1839 btrfs_close_bdev fs/btrfs/volumes.c:1033 [inline] btrfs_close_one_device fs/btrfs/volumes.c:1057 [inline] close_fs_devices.part.0+0x24d/0x8e0 fs/btrfs/volumes.c:1085 close_fs_devices fs/btrfs/volumes.c:1117 [inline] btrfs_close_devices+0x95/0x1f0 fs/btrfs/volumes.c:1103 open_ctree+0x26b/0x61e0 fs/btrfs/disk-io.c:3326 btrfs_fill_super fs/btrfs/super.c:1209 [inline] btrfs_mount_root+0x12e5/0x1830 fs/btrfs/super.c:1613 mount_fs+0xa3/0x310 fs/super.c:1261 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961 vfs_kern_mount+0x3c/0x60 fs/namespace.c:951 btrfs_mount+0x23a/0xaa0 fs/btrfs/super.c:1681 mount_fs+0xa3/0x310 fs/super.c:1261 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2492 [inline] do_mount+0x115c/0x2f50 fs/namespace.c:2822 ksys_mount+0xcf/0x130 fs/namespace.c:3038 __do_sys_mount fs/namespace.c:3052 [inline] __se_sys_mount fs/namespace.c:3049 [inline] __x64_sys_mount+0xba/0x150 fs/namespace.c:3049 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #7 (&fs_devs->device_list_mutex){+.+.}: btrfs_run_dev_stats+0xbb/0xa80 fs/btrfs/volumes.c:7111 commit_cowonly_roots+0x1ce/0xc30 fs/btrfs/transaction.c:1172 btrfs_commit_transaction+0x94a/0x2480 fs/btrfs/transaction.c:2218 btrfs_clear_free_space_tree+0x69d/0xa50 fs/btrfs/free-space-tree.c:1255 open_ctree.cold+0x30/0xc3d fs/btrfs/disk-io.c:3203 btrfs_fill_super fs/btrfs/super.c:1209 [inline] btrfs_mount_root+0x12e5/0x1830 fs/btrfs/super.c:1613 mount_fs+0xa3/0x310 fs/super.c:1261 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961 vfs_kern_mount+0x3c/0x60 fs/namespace.c:951 btrfs_mount+0x23a/0xaa0 fs/btrfs/super.c:1681 mount_fs+0xa3/0x310 fs/super.c:1261 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2492 [inline] do_mount+0x115c/0x2f50 fs/namespace.c:2822 ksys_mount+0xcf/0x130 fs/namespace.c:3038 __do_sys_mount fs/namespace.c:3052 [inline] __se_sys_mount fs/namespace.c:3049 [inline] __x64_sys_mount+0xba/0x150 fs/namespace.c:3049 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #6 (&fs_info->tree_log_mutex){+.+.}: btrfs_commit_transaction+0x8c2/0x2480 fs/btrfs/transaction.c:2176 btrfs_clear_free_space_tree+0x69d/0xa50 fs/btrfs/free-space-tree.c:1255 open_ctree.cold+0x30/0xc3d fs/btrfs/disk-io.c:3203 btrfs_fill_super fs/btrfs/super.c:1209 [inline] btrfs_mount_root+0x12e5/0x1830 fs/btrfs/super.c:1613 mount_fs+0xa3/0x310 fs/super.c:1261 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961 vfs_kern_mount+0x3c/0x60 fs/namespace.c:951 btrfs_mount+0x23a/0xaa0 fs/btrfs/super.c:1681 mount_fs+0xa3/0x310 fs/super.c:1261 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2492 [inline] do_mount+0x115c/0x2f50 fs/namespace.c:2822 ksys_mount+0xcf/0x130 fs/namespace.c:3038 __do_sys_mount fs/namespace.c:3052 [inline] __se_sys_mount fs/namespace.c:3049 [inline] __x64_sys_mount+0xba/0x150 fs/namespace.c:3049 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #5 (&fs_info->reloc_mutex){+.+.}: btrfs_commit_transaction+0x80b/0x2480 fs/btrfs/transaction.c:2120 btrfs_clear_free_space_tree+0x69d/0xa50 fs/btrfs/free-space-tree.c:1255 open_ctree.cold+0x30/0xc3d fs/btrfs/disk-io.c:3203 btrfs_fill_super fs/btrfs/super.c:1209 [inline] btrfs_mount_root+0x12e5/0x1830 fs/btrfs/super.c:1613 mount_fs+0xa3/0x310 fs/super.c:1261 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961 vfs_kern_mount+0x3c/0x60 fs/namespace.c:951 btrfs_mount+0x23a/0xaa0 fs/btrfs/super.c:1681 mount_fs+0xa3/0x310 fs/super.c:1261 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2492 [inline] do_mount+0x115c/0x2f50 fs/namespace.c:2822 ksys_mount+0xcf/0x130 fs/namespace.c:3038 __do_sys_mount fs/namespace.c:3052 [inline] __se_sys_mount fs/namespace.c:3049 [inline] __x64_sys_mount+0xba/0x150 fs/namespace.c:3049 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #4 (sb_internal#5){.+.+}: sb_start_intwrite include/linux/fs.h:1626 [inline] start_transaction+0xa37/0xf90 fs/btrfs/transaction.c:528 btrfs_dirty_inode+0xe3/0x210 fs/btrfs/inode.c:6165 btrfs_update_time+0x33b/0x3d0 fs/btrfs/inode.c:6207 update_time fs/inode.c:1675 [inline] touch_atime+0x23c/0x2a0 fs/inode.c:1746 file_accessed include/linux/fs.h:2123 [inline] btrfs_file_mmap+0x11b/0x160 fs/btrfs/file.c:2274 call_mmap include/linux/fs.h:1826 [inline] mmap_region+0xc94/0x16b0 mm/mmap.c:1757 do_mmap+0x8e8/0x1080 mm/mmap.c:1530 do_mmap_pgoff include/linux/mm.h:2329 [inline] vm_mmap_pgoff+0x197/0x200 mm/util.c:357 ksys_mmap_pgoff+0x298/0x5a0 mm/mmap.c:1580 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #3 (&mm->mmap_sem){++++}: _copy_to_iter+0x3d0/0xea0 lib/iov_iter.c:564 copy_to_iter include/linux/uio.h:106 [inline] skb_copy_datagram_iter+0x469/0x9e0 net/core/datagram.c:431 skb_copy_datagram_msg include/linux/skbuff.h:3347 [inline] unix_dgram_recvmsg+0x3b7/0xdb0 net/unix/af_unix.c:2180 sock_recvmsg_nosec net/socket.c:859 [inline] sock_recvmsg net/socket.c:866 [inline] sock_recvmsg net/socket.c:862 [inline] __sys_recvfrom+0x249/0x3a0 net/socket.c:1956 __do_sys_recvfrom net/socket.c:1974 [inline] __se_sys_recvfrom net/socket.c:1970 [inline] __x64_sys_recvfrom+0xdd/0x1b0 net/socket.c:1970 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #2 (&u->iolock){+.+.}: unix_stream_read_generic+0x2de/0x1a40 net/unix/af_unix.c:2322 unix_stream_recvmsg+0xb1/0xf0 net/unix/af_unix.c:2505 sock_recvmsg_nosec net/socket.c:859 [inline] sock_recvmsg net/socket.c:866 [inline] sock_recvmsg+0xca/0x110 net/socket.c:862 sock_xmit+0x37d/0x5c0 drivers/block/nbd.c:439 nbd_read_stat drivers/block/nbd.c:633 [inline] recv_work+0x1e9/0x1100 drivers/block/nbd.c:732 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 -> #1 ((work_completion)(&args->work)){+.+.}: worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 -> #0 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}: flush_workqueue+0x117/0x13e0 kernel/workqueue.c:2661 drain_workqueue+0x1a5/0x460 kernel/workqueue.c:2826 destroy_workqueue+0x75/0x790 kernel/workqueue.c:4183 nbd_config_put+0x3c5/0x870 drivers/block/nbd.c:1175 nbd_release+0xf4/0x170 drivers/block/nbd.c:1461 __blkdev_put+0x636/0x870 fs/block_dev.c:1819 blkdev_close+0x86/0xb0 fs/block_dev.c:1888 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: (wq_completion)"knbd%d-recv"nbd->index --> nbd_index_mutex --> &nbd->config_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&nbd->config_lock); lock(nbd_index_mutex); lock(&nbd->config_lock); lock((wq_completion)"knbd%d-recv"nbd->index); *** DEADLOCK *** 2 locks held by syz-executor.1/21935: #0: 00000000668a814f (&bdev->bd_mutex){+.+.}, at: __blkdev_put+0xfc/0x870 fs/block_dev.c:1806 #1: 000000001464e3c9 (&nbd->config_lock){+.+.}, at: refcount_dec_and_mutex_lock lib/refcount.c:311 [inline] #1: 000000001464e3c9 (&nbd->config_lock){+.+.}, at: refcount_dec_and_mutex_lock+0x4a/0x80 lib/refcount.c:306 stack backtrace: CPU: 1 PID: 21935 Comm: syz-executor.1 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1222 check_prev_add kernel/locking/lockdep.c:1866 [inline] check_prevs_add kernel/locking/lockdep.c:1979 [inline] validate_chain kernel/locking/lockdep.c:2420 [inline] __lock_acquire+0x30c9/0x3ff0 kernel/locking/lockdep.c:3416 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 flush_workqueue+0x117/0x13e0 kernel/workqueue.c:2661 drain_workqueue+0x1a5/0x460 kernel/workqueue.c:2826 destroy_workqueue+0x75/0x790 kernel/workqueue.c:4183 nbd_config_put+0x3c5/0x870 drivers/block/nbd.c:1175 nbd_release+0xf4/0x170 drivers/block/nbd.c:1461 __blkdev_put+0x636/0x870 fs/block_dev.c:1819 blkdev_close+0x86/0xb0 fs/block_dev.c:1888 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fd13eaadf8b Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44 RSP: 002b:00007ffda7c2fec0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000008 RCX: 00007fd13eaadf8b RDX: 0000000000000000 RSI: 0000001b2fc267d0 RDI: 0000000000000007 RBP: 00007fd13ec1d980 R08: 0000000000000000 R09: 000000003253460c R10: 0000000000000000 R11: 0000000000000293 R12: 000000000006c005 R13: 00007ffda7c2ffc0 R14: 00007fd13ec1c050 R15: 0000000000000032 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. XFS (loop5): Mounting V4 Filesystem XFS (loop5): Ending clean mount XFS (loop5): Quotacheck needed: Please wait. XFS (loop5): Quotacheck: Done. XFS (loop5): Unmounting Filesystem block nbd1: shutting down sockets block nbd1: Device being setup by another task netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. block nbd1: shutting down sockets netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. nf_conntrack: default automatic helper assignment has been turned off for security reasons and CT-based firewall rule not found. Use the iptables CT target to attach helpers instead. XFS (loop2): DAX enabled. Warning: EXPERIMENTAL, use at your own risk XFS (loop2): DAX unsupported by block device. Turning off DAX. XFS (loop2): Mounting V4 Filesystem XFS (loop2): Ending clean mount XFS (loop2): Quotacheck needed: Please wait. XFS (loop2): Quotacheck: Done. XFS (loop2): Unmounting Filesystem XFS (loop5): DAX enabled. Warning: EXPERIMENTAL, use at your own risk XFS (loop5): DAX unsupported by block device. Turning off DAX. XFS (loop5): Mounting V4 Filesystem XFS (loop5): Ending clean mount XFS (loop5): Quotacheck needed: Please wait. XFS (loop5): Quotacheck: Done. XFS (loop4): DAX enabled. Warning: EXPERIMENTAL, use at your own risk XFS (loop4): DAX unsupported by block device. Turning off DAX. XFS (loop3): DAX enabled. Warning: EXPERIMENTAL, use at your own risk XFS (loop4): Mounting V4 Filesystem XFS (loop3): DAX unsupported by block device. Turning off DAX. XFS (loop3): Mounting V4 Filesystem XFS (loop4): Ending clean mount XFS (loop3): Ending clean mount XFS (loop4): Quotacheck needed: Please wait. XFS (loop3): Quotacheck needed: Please wait. XFS (loop4): Quotacheck: Done. XFS (loop3): Quotacheck: Done. XFS (loop5): Unmounting Filesystem XFS (loop3): Unmounting Filesystem XFS (loop4): Unmounting Filesystem XFS (loop3): DAX enabled. Warning: EXPERIMENTAL, use at your own risk XFS (loop3): DAX unsupported by block device. Turning off DAX. XFS (loop3): Mounting V4 Filesystem XFS (loop3): Ending clean mount XFS (loop4): DAX enabled. Warning: EXPERIMENTAL, use at your own risk XFS (loop3): Quotacheck needed: Please wait. XFS (loop4): DAX unsupported by block device. Turning off DAX. XFS (loop3): Quotacheck: Done. XFS (loop5): DAX enabled. Warning: EXPERIMENTAL, use at your own risk XFS (loop5): DAX unsupported by block device. Turning off DAX. XFS (loop5): Mounting V4 Filesystem XFS (loop4): Mounting V4 Filesystem XFS (loop5): Ending clean mount XFS (loop5): Quotacheck needed: Please wait. XFS (loop5): Quotacheck: Done. XFS (loop4): Ending clean mount XFS (loop4): Quotacheck needed: Please wait. XFS (loop4): Quotacheck: Done. XFS (loop3): Unmounting Filesystem XFS (loop4): Unmounting Filesystem XFS (loop5): Unmounting Filesystem XFS (loop5): DAX enabled. Warning: EXPERIMENTAL, use at your own risk XFS (loop5): DAX unsupported by block device. Turning off DAX. XFS (loop5): Mounting V4 Filesystem XFS (loop3): DAX enabled. Warning: EXPERIMENTAL, use at your own risk XFS (loop3): DAX unsupported by block device. Turning off DAX. XFS (loop3): Mounting V4 Filesystem XFS (loop5): Ending clean mount XFS (loop5): Quotacheck needed: Please wait. XFS (loop3): Ending clean mount XFS (loop5): Quotacheck: Done. XFS (loop3): Quotacheck needed: Please wait. XFS (loop4): DAX enabled. Warning: EXPERIMENTAL, use at your own risk XFS (loop4): DAX unsupported by block device. Turning off DAX. XFS (loop3): Quotacheck: Done. XFS (loop4): Mounting V4 Filesystem XFS (loop4): Ending clean mount XFS (loop4): Quotacheck needed: Please wait. XFS (loop4): Quotacheck: Done. XFS (loop5): Unmounting Filesystem XFS (loop3): Unmounting Filesystem XFS (loop4): Unmounting Filesystem XFS (loop3): DAX enabled. Warning: EXPERIMENTAL, use at your own risk XFS (loop3): DAX unsupported by block device. Turning off DAX. XFS (loop3): Mounting V4 Filesystem XFS (loop3): Ending clean mount XFS (loop3): Quotacheck needed: Please wait. XFS (loop5): DAX enabled. Warning: EXPERIMENTAL, use at your own risk XFS (loop5): DAX unsupported by block device. Turning off DAX. XFS (loop3): Quotacheck: Done. XFS (loop5): Mounting V4 Filesystem XFS (loop5): Ending clean mount XFS (loop4): DAX enabled. Warning: EXPERIMENTAL, use at your own risk XFS (loop5): Quotacheck needed: Please wait. XFS (loop4): DAX unsupported by block device. Turning off DAX. XFS (loop4): Mounting V4 Filesystem XFS (loop5): Quotacheck: Done. XFS (loop4): Ending clean mount XFS (loop4): Quotacheck needed: Please wait. XFS (loop4): Quotacheck: Done. XFS (loop3): Unmounting Filesystem XFS (loop5): Unmounting Filesystem XFS (loop4): Unmounting Filesystem