======================================================
WARNING: possible circular locking dependency detected
5.5.0-rc2-next-20191220-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.5/28947 is trying to acquire lock:
ffff888014052690 (&ovl_i_mutex_dir_key[depth]){++++}, at: inode_lock_shared include/linux/fs.h:801 [inline]
ffff888014052690 (&ovl_i_mutex_dir_key[depth]){++++}, at: lookup_slow+0x4a/0x80 fs/namei.c:1773
but task is already holding lock:
ffff8880531efc50 (&sig->cred_guard_mutex){+.+.}, at: __do_sys_perf_event_open+0xeaa/0x2d00 kernel/events/core.c:11257
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&sig->cred_guard_mutex){+.+.}:
__mutex_lock_common kernel/locking/mutex.c:956 [inline]
__mutex_lock+0x156/0x13c0 kernel/locking/mutex.c:1103
mutex_lock_killable_nested+0x16/0x20 kernel/locking/mutex.c:1133
lock_trace+0x4a/0xe0 fs/proc/base.c:406
proc_pid_stack+0xbf/0x200 fs/proc/base.c:450
proc_single_show+0xfd/0x1c0 fs/proc/base.c:756
seq_read+0x4ca/0x1170 fs/seq_file.c:229
do_loop_readv_writev fs/read_write.c:714 [inline]
do_loop_readv_writev fs/read_write.c:701 [inline]
do_iter_read+0x4a4/0x660 fs/read_write.c:935
vfs_readv+0xf0/0x160 fs/read_write.c:997
do_preadv+0x1c4/0x280 fs/read_write.c:1089
__do_sys_preadv fs/read_write.c:1139 [inline]
__se_sys_preadv fs/read_write.c:1134 [inline]
__x64_sys_preadv+0x9a/0xf0 fs/read_write.c:1134
do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #2 (&p->lock){+.+.}:
__mutex_lock_common kernel/locking/mutex.c:956 [inline]
__mutex_lock+0x156/0x13c0 kernel/locking/mutex.c:1103
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118
seq_read+0x71/0x1170 fs/seq_file.c:161
do_loop_readv_writev fs/read_write.c:714 [inline]
do_loop_readv_writev fs/read_write.c:701 [inline]
do_iter_read+0x4a4/0x660 fs/read_write.c:935
vfs_readv+0xf0/0x160 fs/read_write.c:997
kernel_readv fs/splice.c:365 [inline]
default_file_splice_read+0x4fb/0xa20 fs/splice.c:422
do_splice_to+0x127/0x180 fs/splice.c:892
splice_direct_to_actor+0x320/0xa30 fs/splice.c:971
do_splice_direct+0x1da/0x2a0 fs/splice.c:1080
do_sendfile+0x597/0xd00 fs/read_write.c:1464
__do_sys_sendfile64 fs/read_write.c:1525 [inline]
__se_sys_sendfile64 fs/read_write.c:1511 [inline]
__x64_sys_sendfile64+0x1dd/0x220 fs/read_write.c:1511
do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #1 (sb_writers#3){.+.+}:
percpu_down_read include/linux/percpu-rwsem.h:40 [inline]
__sb_start_write+0x241/0x460 fs/super.c:1674
sb_start_write include/linux/fs.h:1649 [inline]
mnt_want_write+0x3f/0xc0 fs/namespace.c:354
ovl_want_write+0x76/0xa0 fs/overlayfs/util.c:21
ovl_do_remove+0xe9/0xd70 fs/overlayfs/dir.c:837
ovl_rmdir+0x1b/0x20 fs/overlayfs/dir.c:887
vfs_rmdir fs/namei.c:4015 [inline]
vfs_rmdir+0x19a/0x4f0 fs/namei.c:3994
do_rmdir+0x39e/0x420 fs/namei.c:4077
__do_sys_rmdir fs/namei.c:4095 [inline]
__se_sys_rmdir fs/namei.c:4093 [inline]
__x64_sys_rmdir+0x36/0x40 fs/namei.c:4093
do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #0 (&ovl_i_mutex_dir_key[depth]){++++}:
check_prev_add kernel/locking/lockdep.c:2476 [inline]
check_prevs_add kernel/locking/lockdep.c:2581 [inline]
validate_chain kernel/locking/lockdep.c:2971 [inline]
__lock_acquire+0x2596/0x4a00 kernel/locking/lockdep.c:3955
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485
down_read+0x95/0x440 kernel/locking/rwsem.c:1495
inode_lock_shared include/linux/fs.h:801 [inline]
lookup_slow+0x4a/0x80 fs/namei.c:1773
walk_component+0x7a7/0x1060 fs/namei.c:1917
lookup_last fs/namei.c:2393 [inline]
path_lookupat.isra.0+0x1ea/0x8c0 fs/namei.c:2438
filename_lookup+0x1a3/0x3e0 fs/namei.c:2468
kern_path+0x36/0x40 fs/namei.c:2554
create_local_trace_uprobe+0x87/0x4a0 kernel/trace/trace_uprobe.c:1547
perf_uprobe_init+0x131/0x210 kernel/trace/trace_event_perf.c:323
perf_uprobe_event_init+0x106/0x1a0 kernel/events/core.c:9162
perf_try_init_event+0x135/0x590 kernel/events/core.c:10462
perf_init_event kernel/events/core.c:10514 [inline]
perf_event_alloc.part.0+0x1769/0x37b0 kernel/events/core.c:10794
perf_event_alloc kernel/events/core.c:10676 [inline]
__do_sys_perf_event_open+0x6f8/0x2d00 kernel/events/core.c:11277
__se_sys_perf_event_open kernel/events/core.c:11151 [inline]
__x64_sys_perf_event_open+0xbe/0x150 kernel/events/core.c:11151
do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
other info that might help us debug this:
Chain exists of:
&ovl_i_mutex_dir_key[depth] --> &p->lock --> &sig->cred_guard_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&sig->cred_guard_mutex);
lock(&p->lock);
lock(&sig->cred_guard_mutex);
lock(&ovl_i_mutex_dir_key[depth]);
*** DEADLOCK ***
2 locks held by syz-executor.5/28947:
#0: ffff8880531efc50 (&sig->cred_guard_mutex){+.+.}, at: __do_sys_perf_event_open+0xeaa/0x2d00 kernel/events/core.c:11257
#1: ffffffff8b6571a8 (&pmus_srcu){....}, at: perf_event_alloc.part.0+0xf04/0x37b0 kernel/events/core.c:10790
stack backtrace:
CPU: 0 PID: 28947 Comm: syz-executor.5 Not tainted 5.5.0-rc2-next-20191220-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x197/0x210 lib/dump_stack.c:118
print_circular_bug.isra.0.cold+0x163/0x172 kernel/locking/lockdep.c:1685
check_noncircular+0x32e/0x3e0 kernel/locking/lockdep.c:1809
check_prev_add kernel/locking/lockdep.c:2476 [inline]
check_prevs_add kernel/locking/lockdep.c:2581 [inline]
validate_chain kernel/locking/lockdep.c:2971 [inline]
__lock_acquire+0x2596/0x4a00 kernel/locking/lockdep.c:3955
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485
down_read+0x95/0x440 kernel/locking/rwsem.c:1495
inode_lock_shared include/linux/fs.h:801 [inline]
lookup_slow+0x4a/0x80 fs/namei.c:1773
walk_component+0x7a7/0x1060 fs/namei.c:1917
lookup_last fs/namei.c:2393 [inline]
path_lookupat.isra.0+0x1ea/0x8c0 fs/namei.c:2438
filename_lookup+0x1a3/0x3e0 fs/namei.c:2468
kern_path+0x36/0x40 fs/namei.c:2554
create_local_trace_uprobe+0x87/0x4a0 kernel/trace/trace_uprobe.c:1547
perf_uprobe_init+0x131/0x210 kernel/trace/trace_event_perf.c:323
perf_uprobe_event_init+0x106/0x1a0 kernel/events/core.c:9162
perf_try_init_event+0x135/0x590 kernel/events/core.c:10462
perf_init_event kernel/events/core.c:10514 [inline]
perf_event_alloc.part.0+0x1769/0x37b0 kernel/events/core.c:10794
perf_event_alloc kernel/events/core.c:10676 [inline]
__do_sys_perf_event_open+0x6f8/0x2d00 kernel/events/core.c:11277
__se_sys_perf_event_open kernel/events/core.c:11151 [inline]
__x64_sys_perf_event_open+0xbe/0x150 kernel/events/core.c:11151
do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a919
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f344e271c78 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045a919
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000180
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 00007f344e2726d4
R13: 00000000004c8806 R14: 00000000004dfe30 R15: 00000000ffffffff