====================================================== WARNING: possible circular locking dependency detected 4.14.262-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.5/10808 is trying to acquire lock: ("dio/%s"sb->s_id){+.+.}, at: [] flush_workqueue+0xcb/0x1310 kernel/workqueue.c:2622 but task is already holding lock: (&sb->s_type->i_mutex_key#23){+.+.}, at: [] inode_lock include/linux/fs.h:719 [inline] (&sb->s_type->i_mutex_key#23){+.+.}, at: [] generic_file_write_iter+0x99/0x650 mm/filemap.c:3205 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&sb->s_type->i_mutex_key#23){+.+.}: down_write+0x34/0x90 kernel/locking/rwsem.c:54 inode_lock include/linux/fs.h:719 [inline] __generic_file_fsync+0x9e/0x190 fs/libfs.c:989 fat_file_fsync+0x73/0x1f0 fs/fat/file.c:165 vfs_fsync_range+0x103/0x260 fs/sync.c:196 generic_write_sync include/linux/fs.h:2684 [inline] dio_complete+0x561/0x8d0 fs/direct-io.c:330 process_one_work+0x793/0x14a0 kernel/workqueue.c:2117 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 -> #1 ((&dio->complete_work)){+.+.}: process_one_work+0x736/0x14a0 kernel/workqueue.c:2093 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 -> #0 ("dio/%s"sb->s_id){+.+.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 flush_workqueue+0xfa/0x1310 kernel/workqueue.c:2625 drain_workqueue+0x177/0x3e0 kernel/workqueue.c:2790 destroy_workqueue+0x71/0x710 kernel/workqueue.c:4116 __alloc_workqueue_key+0xd50/0x1080 kernel/workqueue.c:4093 sb_init_dio_done_wq+0x34/0x80 fs/direct-io.c:624 do_blockdev_direct_IO fs/direct-io.c:1287 [inline] __blockdev_direct_IO+0x3df1/0xdcb0 fs/direct-io.c:1423 blockdev_direct_IO include/linux/fs.h:2994 [inline] fat_direct_IO+0x19b/0x320 fs/fat/inode.c:275 generic_file_direct_write+0x1df/0x420 mm/filemap.c:2958 __generic_file_write_iter+0x2a2/0x590 mm/filemap.c:3137 generic_file_write_iter+0x36f/0x650 mm/filemap.c:3208 call_write_iter include/linux/fs.h:1780 [inline] aio_write+0x2ed/0x560 fs/aio.c:1553 io_submit_one fs/aio.c:1641 [inline] do_io_submit+0x847/0x1570 fs/aio.c:1709 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb other info that might help us debug this: Chain exists of: "dio/%s"sb->s_id --> (&dio->complete_work) --> &sb->s_type->i_mutex_key#23 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#23); lock((&dio->complete_work)); lock(&sb->s_type->i_mutex_key#23); lock("dio/%s"sb->s_id); *** DEADLOCK *** 2 locks held by syz-executor.5/10808: #0: (sb_writers#14){.+.+}, at: [] file_start_write include/linux/fs.h:2714 [inline] #0: (sb_writers#14){.+.+}, at: [] aio_write+0x408/0x560 fs/aio.c:1552 #1: (&sb->s_type->i_mutex_key#23){+.+.}, at: [] inode_lock include/linux/fs.h:719 [inline] #1: (&sb->s_type->i_mutex_key#23){+.+.}, at: [] generic_file_write_iter+0x99/0x650 mm/filemap.c:3205 stack backtrace: CPU: 0 PID: 10808 Comm: syz-executor.5 Not tainted 4.14.262-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 flush_workqueue+0xfa/0x1310 kernel/workqueue.c:2625 drain_workqueue+0x177/0x3e0 kernel/workqueue.c:2790 destroy_workqueue+0x71/0x710 kernel/workqueue.c:4116 __alloc_workqueue_key+0xd50/0x1080 kernel/workqueue.c:4093 sb_init_dio_done_wq+0x34/0x80 fs/direct-io.c:624 do_blockdev_direct_IO fs/direct-io.c:1287 [inline] __blockdev_direct_IO+0x3df1/0xdcb0 fs/direct-io.c:1423 blockdev_direct_IO include/linux/fs.h:2994 [inline] fat_direct_IO+0x19b/0x320 fs/fat/inode.c:275 generic_file_direct_write+0x1df/0x420 mm/filemap.c:2958 __generic_file_write_iter+0x2a2/0x590 mm/filemap.c:3137 generic_file_write_iter+0x36f/0x650 mm/filemap.c:3208 call_write_iter include/linux/fs.h:1780 [inline] aio_write+0x2ed/0x560 fs/aio.c:1553 io_submit_one fs/aio.c:1641 [inline] do_io_submit+0x847/0x1570 fs/aio.c:1709 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f95b4e42fe9 RSP: 002b:00007f95b37b8168 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1 RAX: ffffffffffffffda RBX: 00007f95b4f55f60 RCX: 00007f95b4e42fe9 RDX: 0000000020000540 RSI: 00000000000018af RDI: 00007f95b4f31000 RBP: 00007f95b4e9d08d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe68f5b8df R14: 00007f95b37b8300 R15: 0000000000022000 UDF-fs: warning (device loop0): udf_load_vrs: No anchor found overlayfs: fs on './file0' does not support file handles, falling back to index=off. UDF-fs: Scanning with blocksize 1024 failed UDF-fs: warning (device loop0): udf_load_vrs: No anchor found UDF-fs: Scanning with blocksize 2048 failed UDF-fs: warning (device loop0): udf_load_vrs: No anchor found UDF-fs: Scanning with blocksize 4096 failed UDF-fs: warning (device loop0): udf_fill_super: No partition found (1) FAT-fs (loop5): Unrecognized mount option "./bus" or missing value Bluetooth: hci6 command 0x1003 tx timeout Bluetooth: hci6 sending frame failed (-49) Bluetooth: hci6 command 0x1001 tx timeout Bluetooth: hci6 sending frame failed (-49) Bluetooth: hci6 command 0x1009 tx timeout