======================================================
WARNING: possible circular locking dependency detected
4.14.184-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.0/2281 is trying to acquire lock:
(&p->lock){+.+.}, at: [<ffffffff8193189a>] seq_read+0xba/0x1130 fs/seq_file.c:165
but task is already holding lock:
(sb_writers#3){.+.+}, at: [<ffffffff818b9fce>] file_start_write include/linux/fs.h:2708 [inline]
(sb_writers#3){.+.+}, at: [<ffffffff818b9fce>] do_sendfile+0x82e/0xaf0 fs/read_write.c:1440
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (sb_writers#3){.+.+}:
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+0x1a1/0x2e0 fs/super.c:1363
sb_start_write include/linux/fs.h:1549 [inline]
mnt_want_write+0x3a/0xb0 fs/namespace.c:386
ovl_do_remove+0x65/0xb00 fs/overlayfs/dir.c:759
vfs_rmdir fs/namei.c:3908 [inline]
vfs_rmdir+0x209/0x400 fs/namei.c:3886
do_rmdir+0x2d1/0x340 fs/namei.c:3968
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
-> #2 (&ovl_i_mutex_dir_key[depth]#2){++++}:
down_read+0x37/0xa0 kernel/locking/rwsem.c:24
inode_lock_shared include/linux/fs.h:729 [inline]
do_last fs/namei.c:3333 [inline]
path_openat+0x148c/0x2aa0 fs/namei.c:3569
do_filp_open+0x18e/0x250 fs/namei.c:3603
do_open_execat+0xda/0x440 fs/exec.c:849
do_execveat_common.isra.0+0x680/0x1c50 fs/exec.c:1742
do_execve fs/exec.c:1847 [inline]
SYSC_execve fs/exec.c:1928 [inline]
SyS_execve+0x34/0x40 fs/exec.c:1923
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
-> #1 (&sig->cred_guard_mutex){+.+.}:
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xe8/0x1430 kernel/locking/mutex.c:893
do_io_accounting+0x1c7/0x760 fs/proc/base.c:2726
proc_single_show+0xe7/0x150 fs/proc/base.c:761
seq_read+0x4d2/0x1130 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+0x3e3/0x5a0 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+0x41d/0x870 fs/splice.c:416
do_splice_to+0xfb/0x150 fs/splice.c:880
splice_direct_to_actor+0x20a/0x730 fs/splice.c:952
do_splice_direct+0x164/0x210 fs/splice.c:1061
do_sendfile+0x469/0xaf0 fs/read_write.c:1441
SYSC_sendfile64 fs/read_write.c:1502 [inline]
SyS_sendfile64+0xff/0x110 fs/read_write.c:1488
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
-> #0 (&p->lock){+.+.}:
lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xe8/0x1430 kernel/locking/mutex.c:893
seq_read+0xba/0x1130 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+0x3e3/0x5a0 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+0x41d/0x870 fs/splice.c:416
do_splice_to+0xfb/0x150 fs/splice.c:880
splice_direct_to_actor+0x20a/0x730 fs/splice.c:952
do_splice_direct+0x164/0x210 fs/splice.c:1061
do_sendfile+0x469/0xaf0 fs/read_write.c:1441
SYSC_sendfile64 fs/read_write.c:1502 [inline]
SyS_sendfile64+0xff/0x110 fs/read_write.c:1488
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:
&p->lock --> &ovl_i_mutex_dir_key[depth]#2 --> sb_writers#3
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(sb_writers#3);
lock(&ovl_i_mutex_dir_key[depth]#2);
lock(sb_writers#3);
lock(&p->lock);
*** DEADLOCK ***
1 lock held by syz-executor.0/2281:
#0: (sb_writers#3){.+.+}, at: [<ffffffff818b9fce>] file_start_write include/linux/fs.h:2708 [inline]
#0: (sb_writers#3){.+.+}, at: [<ffffffff818b9fce>] do_sendfile+0x82e/0xaf0 fs/read_write.c:1440
stack backtrace:
CPU: 0 PID: 2281 Comm: syz-executor.0 Not tainted 4.14.184-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+0x1b2/0x283 lib/dump_stack.c:58
print_circular_bug.isra.0.cold+0x2dc/0x425 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+0x3057/0x42a0 kernel/locking/lockdep.c:3491
lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xe8/0x1430 kernel/locking/mutex.c:893
seq_read+0xba/0x1130 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+0x3e3/0x5a0 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+0x41d/0x870 fs/splice.c:416
do_splice_to+0xfb/0x150 fs/splice.c:880
splice_direct_to_actor+0x20a/0x730 fs/splice.c:952
do_splice_direct+0x164/0x210 fs/splice.c:1061
do_sendfile+0x469/0xaf0 fs/read_write.c:1441
SYSC_sendfile64 fs/read_write.c:1502 [inline]
SyS_sendfile64+0xff/0x110 fs/read_write.c:1488
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45ca59
RSP: 002b:00007f33cce4cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00000000004fcea0 RCX: 000000000045ca59
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 000000000000000c
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000209 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000008f3 R14: 00000000004cbc2c R15: 00007f33cce4d6d4
attempt to access beyond end of device
loop5: rw=2049, want=78, limit=63
Buffer I/O error on dev loop5, logical block 77, lost async page write
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'.
attempt to access beyond end of device
loop5: rw=2049, want=79, limit=63
Buffer I/O error on dev loop5, logical block 78, lost async page write
attempt to access beyond end of device
loop5: rw=2049, want=80, limit=63
Buffer I/O error on dev loop5, logical block 79, lost async page write
attempt to access beyond end of device
loop5: rw=2049, want=81, limit=63
Buffer I/O error on dev loop5, logical block 80, lost async page write
attempt to access beyond end of device
loop5: rw=2049, want=130, limit=63
Buffer I/O error on dev loop5, logical block 129, lost async page write
attempt to access beyond end of device
loop5: rw=2049, want=131, limit=63
Buffer I/O error on dev loop5, logical block 130, lost async page write
attempt to access beyond end of device
loop5: rw=2049, want=132, limit=63
Buffer I/O error on dev loop5, logical block 131, lost async page write
attempt to access beyond end of device
loop5: rw=2049, want=133, limit=63
Buffer I/O error on dev loop5, logical block 132, lost async page write
attempt to access beyond end of device
loop5: rw=2049, want=142, limit=63
Buffer I/O error on dev loop5, logical block 141, lost async page write
attempt to access beyond end of device
loop5: rw=2049, want=143, limit=63
Buffer I/O error on dev loop5, logical block 142, lost async page write
attempt to access beyond end of device
loop5: rw=2049, want=144, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=145, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=161, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=3177, limit=63
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'.
attempt to access beyond end of device
loop5: rw=1, want=3833, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=78, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=79, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=80, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=81, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=130, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=131, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=132, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=133, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=142, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=143, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=144, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=145, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=161, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=7929, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=12025, limit=63
attempt to access beyond end of device
loop5: rw=2049, want=14169, limit=63