====================================================== WARNING: possible circular locking dependency detected 4.14.262-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.2/14632 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#22){++++}, at: [] inode_lock include/linux/fs.h:719 [inline] (&sb->s_type->i_mutex_key#22){++++}, 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#22){++++}: 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#22 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#22); lock((&dio->complete_work)); lock(&sb->s_type->i_mutex_key#22); lock("dio/%s"sb->s_id); *** DEADLOCK *** 2 locks held by syz-executor.2/14632: #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#22){++++}, at: [] inode_lock include/linux/fs.h:719 [inline] #1: (&sb->s_type->i_mutex_key#22){++++}, at: [] generic_file_write_iter+0x99/0x650 mm/filemap.c:3205 stack backtrace: CPU: 0 PID: 14632 Comm: syz-executor.2 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: 0033:0x7f8a2470ffe9 RSP: 002b:00007f8a23085168 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1 RAX: ffffffffffffffda RBX: 00007f8a24822f60 RCX: 00007f8a2470ffe9 RDX: 0000000020000540 RSI: 00000000000018af RDI: 00007f8a247fe000 RBP: 00007f8a2476a08d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd2ee3891f R14: 00007f8a23085300 R15: 0000000000022000 overlayfs: fs on 'file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. print_req_error: I/O error, dev loop2, sector 0 print_req_error: I/O error, dev loop2, sector 0 kauditd_printk_skb: 9 callbacks suppressed audit: type=1804 audit(1642520973.764:144): pid=14935 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir268313686/syzkaller.c26LqX/93/bus" dev="sda1" ino=14280 res=1 audit: type=1804 audit(1642520973.804:145): pid=14937 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.0" name="/root/syzkaller-testdir268313686/syzkaller.c26LqX/93/bus" dev="sda1" ino=14280 res=1 audit: type=1804 audit(1642520973.924:146): pid=14966 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir591386045/syzkaller.Jpqn59/97/bus" dev="sda1" ino=14311 res=1 audit: type=1804 audit(1642520973.994:147): pid=14988 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.5" name="/root/syzkaller-testdir591386045/syzkaller.Jpqn59/97/bus" dev="sda1" ino=14311 res=1 IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready netlink: 8 bytes leftover after parsing attributes in process `syz-executor.1'. audit: type=1804 audit(1642520975.164:148): pid=15128 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir268313686/syzkaller.c26LqX/94/bus" dev="sda1" ino=14320 res=1 netlink: 8 bytes leftover after parsing attributes in process `syz-executor.1'. audit: type=1804 audit(1642520975.164:149): pid=15131 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.0" name="/root/syzkaller-testdir268313686/syzkaller.c26LqX/94/bus" dev="sda1" ino=14320 res=1 UDF-fs: bad mount option "(OÉ ¶)?" or missing value IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready netlink: 8 bytes leftover after parsing attributes in process `syz-executor.1'. cramfs: wrong magic UDF-fs: bad mount option "(OÉ ¶)?" or missing value UDF-fs: bad mount option "(OÉ ¶)?" or missing value (syz-executor.3,15227,1):ocfs2_parse_options:1484 ERROR: Unrecognized mount option "[" or missing value (syz-executor.3,15227,1):ocfs2_fill_super:1217 ERROR: status = -22 cramfs: wrong magic print_req_error: I/O error, dev loop3, sector 56 audit: type=1804 audit(1642520976.514:150): pid=15268 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.3" name="/root/syzkaller-testdir197629930/syzkaller.55Ngxp/108/bus" dev="sda1" ino=14329 res=1 audit: type=1804 audit(1642520976.614:151): pid=15279 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.3" name="/root/syzkaller-testdir197629930/syzkaller.55Ngxp/108/bus" dev="sda1" ino=14329 res=1 audit: type=1804 audit(1642520976.774:152): pid=15279 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.3" name="/root/syzkaller-testdir197629930/syzkaller.55Ngxp/108/bus" dev="sda1" ino=14329 res=1 audit: type=1804 audit(1642520977.834:153): pid=15375 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.3" name="/root/syzkaller-testdir197629930/syzkaller.55Ngxp/109/bus" dev="sda1" ino=14326 res=1 Zero length message leads to an empty skb