dlm: dev_write no op 34bde833 10
netlink: 20 bytes leftover after parsing attributes in process `syz-executor.1'.
======================================================
WARNING: possible circular locking dependency detected
4.14.167-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.2/14747 is trying to acquire lock:
 (&sig->cred_guard_mutex){+.+.}, at: [<ffffffff81a99356>] do_io_accounting+0x1d6/0x7b0 fs/proc/base.c:2726

but task is already holding lock:
 (&p->lock){+.+.}, at: [<ffffffff81978541>] seq_read+0xc1/0x1280 fs/seq_file.c:165

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&p->lock){+.+.}:
       lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3994
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893
       mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
       seq_read+0xc1/0x1280 fs/seq_file.c:165
       do_loop_readv_writev fs/read_write.c:695 [inline]
       do_loop_readv_writev fs/read_write.c:682 [inline]
       do_iter_read+0x3e2/0x5b0 fs/read_write.c:919
       vfs_readv+0xd3/0x130 fs/read_write.c:981
       kernel_readv fs/splice.c:361 [inline]
       default_file_splice_read+0x421/0x870 fs/splice.c:416
       do_splice_to+0x105/0x170 fs/splice.c:880
       splice_direct_to_actor+0x222/0x7b0 fs/splice.c:952
       do_splice_direct+0x18d/0x230 fs/splice.c:1061
       do_sendfile+0x4db/0xbd0 fs/read_write.c:1441
       SYSC_sendfile64 fs/read_write.c:1502 [inline]
       SyS_sendfile64+0x102/0x110 fs/read_write.c:1488
       do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
       entry_SYSCALL_64_after_hwframe+0x42/0xb7

-> #2 (sb_writers#4){.+.+}:
       lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3994
       percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline]
       percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
       __sb_start_write+0x1ae/0x2f0 fs/super.c:1363
       sb_start_write include/linux/fs.h:1548 [inline]
       mnt_want_write+0x3f/0xb0 fs/namespace.c:386
       ovl_want_write+0x76/0xa0 fs/overlayfs/util.c:25
       ovl_xattr_set+0x4f/0x270 fs/overlayfs/inode.c:214
       ovl_posix_acl_xattr_set+0x3f9/0x830 fs/overlayfs/super.c:762
       __vfs_setxattr+0xd8/0x130 fs/xattr.c:150
       __vfs_setxattr_noperm+0x102/0x3c0 fs/xattr.c:181
       vfs_setxattr+0xc5/0xf0 fs/xattr.c:224
       setxattr+0x1de/0x350 fs/xattr.c:453
       path_setxattr+0x11f/0x140 fs/xattr.c:472
       SYSC_lsetxattr fs/xattr.c:494 [inline]
       SyS_lsetxattr+0x38/0x50 fs/xattr.c:490
       do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
       entry_SYSCALL_64_after_hwframe+0x42/0xb7

-> #1 (&ovl_i_mutex_dir_key[depth]){++++}:
       lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3994
       down_read+0x3b/0xb0 kernel/locking/rwsem.c:24
       inode_lock_shared include/linux/fs.h:728 [inline]
       do_last fs/namei.c:3330 [inline]
       path_openat+0x191c/0x3f70 fs/namei.c:3566
       do_filp_open+0x18e/0x250 fs/namei.c:3600
       do_open_execat+0xe7/0x4a0 fs/exec.c:849
       do_execveat_common.isra.0+0x6d5/0x1dd0 fs/exec.c:1740
       do_execve fs/exec.c:1847 [inline]
       SYSC_execve fs/exec.c:1928 [inline]
       SyS_execve+0x39/0x50 fs/exec.c:1923
       do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
       entry_SYSCALL_64_after_hwframe+0x42/0xb7

-> #0 (&sig->cred_guard_mutex){+.+.}:
       check_prev_add kernel/locking/lockdep.c:1901 [inline]
       check_prevs_add kernel/locking/lockdep.c:2018 [inline]
       validate_chain kernel/locking/lockdep.c:2460 [inline]
       __lock_acquire+0x2cb3/0x4620 kernel/locking/lockdep.c:3487
       lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3994
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893
       mutex_lock_killable_nested+0x16/0x20 kernel/locking/mutex.c:923
       do_io_accounting+0x1d6/0x7b0 fs/proc/base.c:2726
       proc_tgid_io_accounting+0x23/0x30 fs/proc/base.c:2775
       proc_single_show+0xf0/0x160 fs/proc/base.c:761
       seq_read+0x51a/0x1280 fs/seq_file.c:237
       do_loop_readv_writev fs/read_write.c:695 [inline]
       do_loop_readv_writev fs/read_write.c:682 [inline]
       do_iter_read+0x3e2/0x5b0 fs/read_write.c:919
       vfs_readv+0xd3/0x130 fs/read_write.c:981
       kernel_readv fs/splice.c:361 [inline]
       default_file_splice_read+0x421/0x870 fs/splice.c:416
       do_splice_to+0x105/0x170 fs/splice.c:880
       splice_direct_to_actor+0x222/0x7b0 fs/splice.c:952
       do_splice_direct+0x18d/0x230 fs/splice.c:1061
       do_sendfile+0x4db/0xbd0 fs/read_write.c:1441
       SYSC_sendfile64 fs/read_write.c:1502 [inline]
       SyS_sendfile64+0x102/0x110 fs/read_write.c:1488
       do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
       entry_SYSCALL_64_after_hwframe+0x42/0xb7

other info that might help us debug this:

Chain exists of:
  &sig->cred_guard_mutex --> sb_writers#4 --> &p->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&p->lock);
                               lock(sb_writers#4);
                               lock(&p->lock);
  lock(&sig->cred_guard_mutex);

 *** DEADLOCK ***

1 lock held by syz-executor.2/14747:
 #0:  (&p->lock){+.+.}, at: [<ffffffff81978541>] seq_read+0xc1/0x1280 fs/seq_file.c:165

stack backtrace:
CPU: 1 PID: 14747 Comm: syz-executor.2 Not tainted 4.14.167-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+0x142/0x197 lib/dump_stack.c:58
 print_circular_bug.isra.0.cold+0x1cc/0x28f kernel/locking/lockdep.c:1258
 check_prev_add kernel/locking/lockdep.c:1901 [inline]
 check_prevs_add kernel/locking/lockdep.c:2018 [inline]
 validate_chain kernel/locking/lockdep.c:2460 [inline]
 __lock_acquire+0x2cb3/0x4620 kernel/locking/lockdep.c:3487
 lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3994
 __mutex_lock_common kernel/locking/mutex.c:756 [inline]
 __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893
 mutex_lock_killable_nested+0x16/0x20 kernel/locking/mutex.c:923
 do_io_accounting+0x1d6/0x7b0 fs/proc/base.c:2726
 proc_tgid_io_accounting+0x23/0x30 fs/proc/base.c:2775
 proc_single_show+0xf0/0x160 fs/proc/base.c:761
 seq_read+0x51a/0x1280 fs/seq_file.c:237
 do_loop_readv_writev fs/read_write.c:695 [inline]
 do_loop_readv_writev fs/read_write.c:682 [inline]
 do_iter_read+0x3e2/0x5b0 fs/read_write.c:919
 vfs_readv+0xd3/0x130 fs/read_write.c:981
 kernel_readv fs/splice.c:361 [inline]
 default_file_splice_read+0x421/0x870 fs/splice.c:416
 do_splice_to+0x105/0x170 fs/splice.c:880
 splice_direct_to_actor+0x222/0x7b0 fs/splice.c:952
 do_splice_direct+0x18d/0x230 fs/splice.c:1061
 do_sendfile+0x4db/0xbd0 fs/read_write.c:1441
 SYSC_sendfile64 fs/read_write.c:1502 [inline]
 SyS_sendfile64+0x102/0x110 fs/read_write.c:1488
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45b349
RSP: 002b:00007fbab7f02c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fbab7f036d4 RCX: 000000000045b349
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 000000000000000b
RBP: 000000000075c118 R08: 0000000000000000 R09: 0000000000000000
R10: 000000007ffff000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000008a6 R14: 00000000004ca018 R15: 000000000075c124
ntfs: (device loop0): ntfs_fill_super(): Unable to determine device size.
FAT-fs (loop3): bogus number of reserved sectors
dlm: dev_write no op 34bde833 10
FAT-fs (loop3): Can't find a valid FAT filesystem
input: syz1 as /devices/virtual/input/input20
uinput: write device info first
input: syz1 as /devices/virtual/input/input22
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=7952 sclass=netlink_route_socket pig=14817 comm=syz-executor.0
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=7952 sclass=netlink_route_socket pig=14820 comm=syz-executor.0
input: syz1 as /devices/virtual/input/input23
(unnamed net_device) (uninitialized): option lp_interval: invalid value (18446744073709551615)
(unnamed net_device) (uninitialized): option lp_interval: allowed values 1 - 2147483647
IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready
input: syz1 as /devices/virtual/input/input24
xt_HMARK: proto mask must be zero with L3 mode
netlink: 36 bytes leftover after parsing attributes in process `syz-executor.5'.
device vlan3 entered promiscuous mode
device gretap0 entered promiscuous mode
device gretap0 left promiscuous mode
netlink: 36 bytes leftover after parsing attributes in process `syz-executor.5'.
device vlan3 entered promiscuous mode
device gretap0 entered promiscuous mode
device gretap0 left promiscuous mode
input: syz1 as /devices/virtual/input/input25
sd 0:0:1:0: [sg0] tag#5592 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK
sd 0:0:1:0: [sg0] tag#5592 CDB: Management protocol in
sd 0:0:1:0: [sg0] tag#5592 CDB[00]: a3 30 a8 da a6 f1 dd d8 94 9e 8c 73 1a d5 c9 35
sd 0:0:1:0: [sg0] tag#5592 CDB[10]: 4f da 2e c5 95 aa 4e 7a 13 6c e2 1e b9 a5 a4 e7
sd 0:0:1:0: [sg0] tag#5592 CDB[20]: 50
input: syz1 as /devices/virtual/input/input26
input: syz1 as /devices/virtual/input/input27
overlayfs: filesystem on './file0' not supported as upperdir
input: syz1 as /devices/virtual/input/input28
input: syz1 as /devices/virtual/input/input29
sd 0:0:1:0: [sg0] tag#5614 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK
sd 0:0:1:0: [sg0] tag#5606 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK
sd 0:0:1:0: [sg0] tag#5614 CDB: Management protocol in
sd 0:0:1:0: [sg0] tag#5606 CDB: Management protocol in
sd 0:0:1:0: [sg0] tag#5614 CDB[00]: a3 30 a8 da a6 f1 dd d8 94 9e 8c 73 1a d5 c9 35
sd 0:0:1:0: [sg0] tag#5614 CDB[10]: 4f da 2e c5 95 aa 4e 7a 13 6c e2 1e b9 a5 a4 e7
sd 0:0:1:0: [sg0] tag#5606 CDB[00]: a3 30 a8 da a6 f1 dd d8 94 9e 8c 73 1a d5 c9 35
sd 0:0:1:0: [sg0] tag#5614 CDB[20]: 50
sd 0:0:1:0: [sg0] tag#5606 CDB[10]: 4f da 2e c5 95 aa 4e 7a 13 6c e2 1e b9 a5 a4 e7
sd 0:0:1:0: [sg0] tag#5606 CDB[20]: 50
sd 0:0:1:0: [sg0] tag#5606 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK
sd 0:0:1:0: [sg0] tag#5606 CDB: Management protocol in
sd 0:0:1:0: [sg0] tag#5606 CDB[00]: a3 30 a8 da a6 f1 dd d8 94 9e 8c 73 1a d5 c9 35
sd 0:0:1:0: [sg0] tag#5606 CDB[10]: 4f da 2e c5 95 aa 4e 7a 13 6c e2 1e b9 a5 a4 e7
sd 0:0:1:0: [sg0] tag#5606 CDB[20]: 50
sd 0:0:1:0: [sg0] tag#5606 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK
sd 0:0:1:0: [sg0] tag#5606 CDB: Management protocol in
sd 0:0:1:0: [sg0] tag#5606 CDB[00]: a3 30 a8 da a6 f1 dd d8 94 9e 8c 73 1a d5 c9 35
sd 0:0:1:0: [sg0] tag#5606 CDB[10]: 4f da 2e c5 95 aa 4e 7a 13 6c e2 1e b9 a5 a4 e7
sd 0:0:1:0: [sg0] tag#5606 CDB[20]: 50
input: syz1 as /devices/virtual/input/input30
input: syz1 as /devices/virtual/input/input31
input: syz1 as /devices/virtual/input/input32
sd 0:0:1:0: [sg0] tag#5614 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK
sd 0:0:1:0: [sg0] tag#5614 CDB: Management protocol in
sd 0:0:1:0: [sg0] tag#5614 CDB[00]: a3 30 a8 da a6 f1 dd d8 94 9e 8c 73 1a d5 c9 35
sd 0:0:1:0: [sg0] tag#5614 CDB[10]: 4f da 2e c5 95 aa 4e 7a 13 6c e2 1e b9 a5 a4 e7
sd 0:0:1:0: [sg0] tag#5606 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK
sd 0:0:1:0: [sg0] tag#5614 CDB[20]: 50
sd 0:0:1:0: [sg0] tag#5606 CDB: Management protocol in
sd 0:0:1:0: [sg0] tag#5606 CDB[00]: a3 30 a8 da a6 f1 dd d8 94 9e 8c 73 1a d5 c9 35
sd 0:0:1:0: [sg0] tag#5606 CDB[10]: 4f da 2e c5 95 aa 4e 7a 13 6c e2 1e b9 a5 a4 e7
sd 0:0:1:0: [sg0] tag#5606 CDB[20]: 50
sd 0:0:1:0: [sg0] tag#5606 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK
sd 0:0:1:0: [sg0] tag#5606 CDB: Management protocol in
sd 0:0:1:0: [sg0] tag#5606 CDB[00]: a3 30 a8 da a6 f1 dd d8 94 9e 8c 73 1a d5 c9 35
sd 0:0:1:0: [sg0] tag#5606 CDB[10]: 4f da 2e c5 95 aa 4e 7a 13 6c e2 1e b9 a5 a4 e7
sd 0:0:1:0: [sg0] tag#5606 CDB[20]: 50
sd 0:0:1:0: [sg0] tag#5614 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK
sd 0:0:1:0: [sg0] tag#5614 CDB: Management protocol in
sd 0:0:1:0: [sg0] tag#5614 CDB[00]: a3 30 a8 da a6 f1 dd d8 94 9e 8c 73 1a d5 c9 35
sd 0:0:1:0: [sg0] tag#5614 CDB[10]: 4f da 2e c5 95 aa 4e 7a 13 6c e2 1e b9 a5 a4 e7
sd 0:0:1:0: [sg0] tag#5614 CDB[20]: 50
sd 0:0:1:0: [sg0] tag#5606 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK
sd 0:0:1:0: [sg0] tag#5606 CDB: Management protocol in
sd 0:0:1:0: [sg0] tag#5606 CDB[00]: a3 30 a8 da a6 f1 dd d8 94 9e 8c 73 1a d5 c9 35
sd 0:0:1:0: [sg0] tag#5606 CDB[10]: 4f da 2e c5 95 aa 4e 7a 13 6c e2 1e b9 a5 a4 e7
sd 0:0:1:0: [sg0] tag#5606 CDB[20]: 50
input: syz1 as /devices/virtual/input/input33
input: syz1 as /devices/virtual/input/input34
NOHZ: local_softirq_pending 08
input: syz1 as /devices/virtual/input/input35
input: syz1 as /devices/virtual/input/input36
dlm: dev_write no op 34bde833 10
input: syz1 as /devices/virtual/input/input37
input: syz1 as /devices/virtual/input/input38
input: syz1 as /devices/virtual/input/input39
input: syz1 as /devices/virtual/input/input40
input: syz1 as /devices/virtual/input/input41
input: syz1 as /devices/virtual/input/input42
input: syz1 as /devices/virtual/input/input43
input: syz1 as /devices/virtual/input/input44
input: syz1 as /devices/virtual/input/input45
input: syz1 as /devices/virtual/input/input46
scsi_io_completion: 6 callbacks suppressed
sd 0:0:1:0: [sg0] tag#5614 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK
sd 0:0:1:0: [sg0] tag#5614 CDB: Management protocol in
sd 0:0:1:0: [sg0] tag#5614 CDB[00]: a3 30 a8 da a6 f1 dd d8 94 9e 8c 73 1a d5 c9 35
sd 0:0:1:0: [sg0] tag#5614 CDB[10]: 4f da 2e c5 95 aa 4e 7a 13 6c e2 1e b9 a5 a4 e7
sd 0:0:1:0: [sg0] tag#5614 CDB[20]: 50
sd 0:0:1:0: [sg0] tag#5614 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK
input: syz1 as /devices/virtual/input/input47
sd 0:0:1:0: [sg0] tag#5614 CDB: Management protocol in
sd 0:0:1:0: [sg0] tag#5614 CDB[00]: a3 30 a8 da a6 f1 dd d8 94 9e 8c 73 1a d5 c9 35
sd 0:0:1:0: [sg0] tag#5614 CDB[10]: 4f da 2e c5 95 aa 4e 7a 13 6c e2 1e b9 a5 a4 e7
input: syz1 as /devices/virtual/input/input48
sd 0:0:1:0: [sg0] tag#5614 CDB[20]: 50
input: syz1 as /devices/virtual/input/input49
input: syz1 as /devices/virtual/input/input50
input: syz1 as /devices/virtual/input/input51
input: syz1 as /devices/virtual/input/input52