====================================================== WARNING: possible circular locking dependency detected 4.14.262-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/10801 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#24){++++}, at: [] inode_lock include/linux/fs.h:719 [inline] (&sb->s_type->i_mutex_key#24){++++}, 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#24){++++}: 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#24 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#24); lock((&dio->complete_work)); lock(&sb->s_type->i_mutex_key#24); lock("dio/%s"sb->s_id); *** DEADLOCK *** 2 locks held by syz-executor.4/10801: #0: (sb_writers#16){.+.+}, at: [] file_start_write include/linux/fs.h:2714 [inline] #0: (sb_writers#16){.+.+}, at: [] aio_write+0x408/0x560 fs/aio.c:1552 #1: (&sb->s_type->i_mutex_key#24){++++}, at: [] inode_lock include/linux/fs.h:719 [inline] #1: (&sb->s_type->i_mutex_key#24){++++}, at: [] generic_file_write_iter+0x99/0x650 mm/filemap.c:3205 stack backtrace: CPU: 1 PID: 10801 Comm: syz-executor.4 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: 0033:0x7fb7e3917fe9 RSP: 002b:00007fb7e228d168 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1 RAX: ffffffffffffffda RBX: 00007fb7e3a2af60 RCX: 00007fb7e3917fe9 RDX: 0000000020000540 RSI: 0000000000001801 RDI: 00007fb7e3a06000 RBP: 00007fb7e397208d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc019a36af R14: 00007fb7e228d300 R15: 0000000000022000 audit: type=1800 audit(1642154339.514:8): pid=10987 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="bus" dev="sda1" ino=13932 res=0 audit: type=1800 audit(1642154339.534:9): pid=10985 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="bus" dev="sda1" ino=13932 res=0 (unnamed net_device) (uninitialized): option primary: mode dependency failed, not supported in mode broadcast(3) audit: type=1804 audit(1642154339.554:10): pid=10985 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir812999783/syzkaller.DZmTQO/22/bus" dev="sda1" ino=13932 res=1 audit: type=1800 audit(1642154340.134:11): pid=11026 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="bus" dev="sda1" ino=13980 res=0 audit: type=1800 audit(1642154340.134:12): pid=11026 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="bus" dev="sda1" ino=13980 res=0 EXT4-fs (loop3): VFS: Can't find ext4 filesystem audit: type=1804 audit(1642154340.164:13): pid=11026 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir812999783/syzkaller.DZmTQO/23/bus" dev="sda1" ino=13980 res=1 audit: type=1804 audit(1642154340.304:14): pid=11027 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.4" name="/root/syzkaller-testdir812999783/syzkaller.DZmTQO/23/bus" dev="sda1" ino=13980 res=1 audit: type=1804 audit(1642154340.314:15): pid=11028 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir812999783/syzkaller.DZmTQO/23/bus" dev="sda1" ino=13980 res=1 audit: type=1800 audit(1642154340.924:16): pid=11054 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="bus" dev="sda1" ino=13973 res=0 audit: type=1800 audit(1642154340.934:17): pid=11053 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="bus" dev="sda1" ino=13973 res=0 audit: type=1804 audit(1642154341.034:18): pid=11053 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir974886918/syzkaller.VKV5hy/37/bus" dev="sda1" ino=13973 res=1 audit: type=1800 audit(1642154341.184:19): pid=11070 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="bus" dev="sda1" ino=13985 res=0 (unnamed net_device) (uninitialized): option primary: mode dependency failed, not supported in mode broadcast(3) (unnamed net_device) (uninitialized): option primary: mode dependency failed, not supported in mode broadcast(3) (unnamed net_device) (uninitialized): option primary: mode dependency failed, not supported in mode broadcast(3) (unnamed net_device) (uninitialized): option primary: mode dependency failed, not supported in mode broadcast(3) EXT4-fs (loop5): mounted filesystem without journal. Opts: ,errors=continue (unnamed net_device) (uninitialized): option primary: mode dependency failed, not supported in mode broadcast(3) (unnamed net_device) (uninitialized): option primary: mode dependency failed, not supported in mode broadcast(3) EXT4-fs (loop5): mounted filesystem without journal. Opts: ,errors=continue EXT4-fs (loop3): VFS: Can't find ext4 filesystem squashfs: SQUASHFS error: Can't find a SQUASHFS superblock on loop4 (unnamed net_device) (uninitialized): option primary: mode dependency failed, not supported in mode broadcast(3) EXT4-fs (loop5): mounted filesystem without journal. Opts: ,errors=continue squashfs: SQUASHFS error: Can't find a SQUASHFS superblock on loop4 squashfs: SQUASHFS error: Can't find a SQUASHFS superblock on loop4