====================================================== WARNING: possible circular locking dependency detected 5.0.0-rc4+ #56 Not tainted ------------------------------------------------------ syz-executor4/17204 is trying to acquire lock: 00000000f3301319 (&ovl_i_mutex_dir_key[depth]#2){++++}, at: inode_lock_shared include/linux/fs.h:767 [inline] 00000000f3301319 (&ovl_i_mutex_dir_key[depth]#2){++++}, at: lookup_slow+0x4a/0x80 fs/namei.c:1687 but task is already holding lock: 000000005677125e (&sig->cred_guard_mutex){+.+.}, at: __do_sys_perf_event_open+0x6e1/0x2690 kernel/events/core.c:10511 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:925 [inline] __mutex_lock+0xf7/0x1310 kernel/locking/mutex.c:1072 mutex_lock_killable_nested+0x16/0x20 kernel/locking/mutex.c:1102 lock_trace+0x4a/0xe0 fs/proc/base.c:384 proc_pid_syscall+0x98/0x250 fs/proc/base.c:619 proc_single_show+0xf6/0x180 fs/proc/base.c:739 seq_read+0x4db/0x1130 fs/seq_file.c:229 __vfs_read+0x116/0x8c0 fs/read_write.c:416 vfs_read+0x194/0x3e0 fs/read_write.c:452 ksys_read+0xea/0x1f0 fs/read_write.c:578 __do_sys_read fs/read_write.c:588 [inline] __se_sys_read fs/read_write.c:586 [inline] __x64_sys_read+0x73/0xb0 fs/read_write.c:586 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #2 (&p->lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:925 [inline] __mutex_lock+0xf7/0x1310 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 seq_read+0x71/0x1130 fs/seq_file.c:161 do_loop_readv_writev fs/read_write.c:700 [inline] do_loop_readv_writev fs/read_write.c:687 [inline] do_iter_read+0x4a9/0x660 fs/read_write.c:921 vfs_readv+0xf0/0x160 fs/read_write.c:983 kernel_readv fs/splice.c:362 [inline] default_file_splice_read+0x475/0x890 fs/splice.c:417 do_splice_to+0x12a/0x190 fs/splice.c:880 splice_direct_to_actor+0x2d2/0x970 fs/splice.c:957 do_splice_direct+0x1da/0x2a0 fs/splice.c:1066 do_sendfile+0x597/0xd00 fs/read_write.c:1436 __do_sys_sendfile64 fs/read_write.c:1497 [inline] __se_sys_sendfile64 fs/read_write.c:1483 [inline] __x64_sys_sendfile64+0x1dd/0x220 fs/read_write.c:1483 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (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+0x20b/0x360 fs/super.c:1389 sb_start_write include/linux/fs.h:1603 [inline] mnt_want_write+0x3f/0xc0 fs/namespace.c:357 ovl_want_write+0x76/0xa0 fs/overlayfs/util.c:24 ovl_create_object+0xb3/0x2c0 fs/overlayfs/dir.c:599 ovl_create+0x28/0x30 fs/overlayfs/dir.c:630 lookup_open+0x12e0/0x1b10 fs/namei.c:3234 do_last fs/namei.c:3324 [inline] path_openat+0x149a/0x4690 fs/namei.c:3534 do_filp_open+0x1a1/0x280 fs/namei.c:3564 do_sys_open+0x3fe/0x5d0 fs/open.c:1063 ksys_open include/linux/syscalls.h:1298 [inline] __do_sys_creat fs/open.c:1121 [inline] __se_sys_creat fs/open.c:1119 [inline] __x64_sys_creat+0x61/0x80 fs/open.c:1119 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&ovl_i_mutex_dir_key[depth]#2){++++}: lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3841 down_read+0x3b/0x90 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:767 [inline] lookup_slow+0x4a/0x80 fs/namei.c:1687 walk_component+0x74b/0x2000 fs/namei.c:1810 lookup_last fs/namei.c:2273 [inline] path_lookupat.isra.0+0x1f5/0x8d0 fs/namei.c:2318 filename_lookup+0x1b0/0x410 fs/namei.c:2348 kern_path+0x36/0x40 fs/namei.c:2434 create_local_trace_uprobe+0x87/0x4e0 kernel/trace/trace_uprobe.c:1357 perf_uprobe_init+0x1a2/0x290 kernel/trace/trace_event_perf.c:316 perf_uprobe_event_init+0x106/0x1a0 kernel/events/core.c:8503 perf_try_init_event+0x137/0x2f0 kernel/events/core.c:9770 perf_init_event kernel/events/core.c:9801 [inline] perf_event_alloc.part.0+0x1d08/0x2e00 kernel/events/core.c:10074 perf_event_alloc kernel/events/core.c:10430 [inline] __do_sys_perf_event_open+0x842/0x2690 kernel/events/core.c:10531 __se_sys_perf_event_open kernel/events/core.c:10420 [inline] __x64_sys_perf_event_open+0xbe/0x150 kernel/events/core.c:10420 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: &ovl_i_mutex_dir_key[depth]#2 --> &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]#2); *** DEADLOCK *** 2 locks held by syz-executor4/17204: #0: 000000005677125e (&sig->cred_guard_mutex){+.+.}, at: __do_sys_perf_event_open+0x6e1/0x2690 kernel/events/core.c:10511 #1: 0000000031b7178e (&pmus_srcu){....}, at: perf_event_alloc.part.0+0xd56/0x2e00 kernel/events/core.c:10070 stack backtrace: CPU: 0 PID: 17204 Comm: syz-executor4 Not tainted 5.0.0-rc4+ #56 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+0x172/0x1f0 lib/dump_stack.c:113 print_circular_bug.isra.0.cold+0x1cc/0x28f kernel/locking/lockdep.c:1224 check_prev_add kernel/locking/lockdep.c:1866 [inline] check_prevs_add kernel/locking/lockdep.c:1979 [inline] validate_chain kernel/locking/lockdep.c:2350 [inline] __lock_acquire+0x2f00/0x4700 kernel/locking/lockdep.c:3338 lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3841 down_read+0x3b/0x90 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:767 [inline] lookup_slow+0x4a/0x80 fs/namei.c:1687 walk_component+0x74b/0x2000 fs/namei.c:1810 lookup_last fs/namei.c:2273 [inline] path_lookupat.isra.0+0x1f5/0x8d0 fs/namei.c:2318 filename_lookup+0x1b0/0x410 fs/namei.c:2348 kern_path+0x36/0x40 fs/namei.c:2434 create_local_trace_uprobe+0x87/0x4e0 kernel/trace/trace_uprobe.c:1357 perf_uprobe_init+0x1a2/0x290 kernel/trace/trace_event_perf.c:316 perf_uprobe_event_init+0x106/0x1a0 kernel/events/core.c:8503 perf_try_init_event+0x137/0x2f0 kernel/events/core.c:9770 perf_init_event kernel/events/core.c:9801 [inline] perf_event_alloc.part.0+0x1d08/0x2e00 kernel/events/core.c:10074 perf_event_alloc kernel/events/core.c:10430 [inline] __do_sys_perf_event_open+0x842/0x2690 kernel/events/core.c:10531 __se_sys_perf_event_open kernel/events/core.c:10420 [inline] __x64_sys_perf_event_open+0xbe/0x150 kernel/events/core.c:10420 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457e39 Code: ad b8 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 b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007efd5d139c78 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000457e39 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000180 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 00007efd5d13a6d4 R13: 00000000004c443f R14: 00000000004d7a48 R15: 00000000ffffffff net_ratelimit: 16 callbacks suppressed protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 kobject: '0:92' (000000003ed1b9a8): kobject_add_internal: parent: 'bdi', set: 'devices' kobject: '0:92' (000000003ed1b9a8): kobject_uevent_env kobject: '0:92' (000000003ed1b9a8): fill_kobj_path: path = '/devices/virtual/bdi/0:92' overlayfs: './file0' not a directory kobject: '0:92' (000000003ed1b9a8): kobject_uevent_env kobject: '0:92' (000000003ed1b9a8): fill_kobj_path: path = '/devices/virtual/bdi/0:92' kobject: '0:92' (000000003ed1b9a8): kobject_cleanup, parent (null) kobject: 'loop0' (00000000a7e2f38c): kobject_uevent_env kobject: '0:92' (000000003ed1b9a8): calling ktype release kobject: 'loop0' (00000000a7e2f38c): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: '0:92': free name kobject: '0:90' (00000000e46de496): kobject_add_internal: parent: 'bdi', set: 'devices' kobject: '0:90' (00000000e46de496): kobject_uevent_env kobject: '0:90' (00000000e46de496): fill_kobj_path: path = '/devices/virtual/bdi/0:90' kobject: 'loop0' (00000000a7e2f38c): kobject_uevent_env kobject: 'loop0' (00000000a7e2f38c): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: '0:94' (0000000052d2d946): kobject_add_internal: parent: 'bdi', set: 'devices' IPVS: Schedule: port zero only supported in persistent services, check your ipvs configuration kobject: '0:94' (0000000052d2d946): kobject_uevent_env kobject: '0:94' (0000000052d2d946): fill_kobj_path: path = '/devices/virtual/bdi/0:94' IPVS: Schedule: port zero only supported in persistent services, check your ipvs configuration kobject: 'loop0' (00000000a7e2f38c): kobject_uevent_env kobject: 'loop0' (00000000a7e2f38c): fill_kobj_path: path = '/devices/virtual/block/loop0' IPVS: Schedule: port zero only supported in persistent services, check your ipvs configuration IPVS: Schedule: port zero only supported in persistent services, check your ipvs configuration kobject: 'loop0' (00000000a7e2f38c): kobject_uevent_env kobject: 'loop0' (00000000a7e2f38c): fill_kobj_path: path = '/devices/virtual/block/loop0' print_req_error: 234 callbacks suppressed print_req_error: I/O error, dev loop0, sector 0 flags 0 buffer_io_error: 234 callbacks suppressed Buffer I/O error on dev loop0, logical block 0, async page read print_req_error: I/O error, dev loop0, sector 0 flags 0 Buffer I/O error on dev loop0, logical block 0, async page read print_req_error: I/O error, dev loop0, sector 0 flags 0 Buffer I/O error on dev loop0, logical block 0, async page read print_req_error: I/O error, dev loop0, sector 0 flags 0 Buffer I/O error on dev loop0, logical block 0, async page read print_req_error: I/O error, dev loop0, sector 0 flags 0 Buffer I/O error on dev loop0, logical block 0, async page read print_req_error: I/O error, dev loop0, sector 0 flags 0 Buffer I/O error on dev loop0, logical block 0, async page read print_req_error: I/O error, dev loop0, sector 0 flags 0 Buffer I/O error on dev loop0, logical block 0, async page read print_req_error: I/O error, dev loop0, sector 0 flags 0 Buffer I/O error on dev loop0, logical block 0, async page read print_req_error: I/O error, dev loop0, sector 0 flags 0 Buffer I/O error on dev loop0, logical block 0, async page read print_req_error: I/O error, dev loop0, sector 0 flags 0 Buffer I/O error on dev loop0, logical block 0, async page read IPVS: Schedule: port zero only supported in persistent services, check your ipvs configuration IPVS: Schedule: port zero only supported in persistent services, check your ipvs configuration IPVS: Schedule: port zero only supported in persistent services, check your ipvs configuration kobject: '0:92' (0000000057e3beaa): kobject_add_internal: parent: 'bdi', set: 'devices' kobject: '0:92' (0000000057e3beaa): kobject_uevent_env kobject: '0:92' (0000000057e3beaa): fill_kobj_path: path = '/devices/virtual/bdi/0:92' kobject: '0:92' (0000000057e3beaa): kobject_uevent_env kobject: '0:92' (0000000057e3beaa): fill_kobj_path: path = '/devices/virtual/bdi/0:92' kobject: '0:92' (0000000057e3beaa): kobject_cleanup, parent (null) kobject: '0:92' (0000000057e3beaa): calling ktype release kobject: '0:92': free name kobject: '0:92' (0000000048e4469c): kobject_add_internal: parent: 'bdi', set: 'devices' kobject: '0:92' (0000000048e4469c): kobject_uevent_env kobject: '0:92' (0000000048e4469c): fill_kobj_path: path = '/devices/virtual/bdi/0:92' kobject: 'loop0' (00000000a7e2f38c): kobject_uevent_env kobject: 'loop0' (00000000a7e2f38c): fill_kobj_path: path = '/devices/virtual/block/loop0' IPVS: Schedule: port zero only supported in persistent services, check your ipvs configuration kobject: '0:96' (000000007fb04ee0): kobject_add_internal: parent: 'bdi', set: 'devices' kobject: '0:96' (000000007fb04ee0): kobject_uevent_env kobject: '0:96' (000000007fb04ee0): fill_kobj_path: path = '/devices/virtual/bdi/0:96' kobject: '0:96' (000000007fb04ee0): kobject_uevent_env kobject: '0:96' (000000007fb04ee0): fill_kobj_path: path = '/devices/virtual/bdi/0:96' kobject: '0:96' (000000007fb04ee0): kobject_cleanup, parent (null) kobject: '0:96' (000000007fb04ee0): calling ktype release kobject: '0:96': free name overlayfs: filesystem on './file0' not supported as upperdir kobject: '0:96' (00000000746a710f): kobject_add_internal: parent: 'bdi', set: 'devices' kobject: '0:96' (00000000746a710f): kobject_uevent_env kobject: '0:96' (00000000746a710f): fill_kobj_path: path = '/devices/virtual/bdi/0:96' net_ratelimit: 24 callbacks suppressed protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 kobject: '0:98' (000000001bdfdff6): kobject_add_internal: parent: 'bdi', set: 'devices' kobject: '0:98' (000000001bdfdff6): kobject_uevent_env kobject: '0:98' (000000001bdfdff6): fill_kobj_path: path = '/devices/virtual/bdi/0:98' kobject: 'loop0' (00000000a7e2f38c): kobject_uevent_env kobject: 'loop0' (00000000a7e2f38c): fill_kobj_path: path = '/devices/virtual/block/loop0' IPVS: Schedule: port zero only supported in persistent services, check your ipvs configuration kobject: '0:100' (000000004409e525): kobject_add_internal: parent: 'bdi', set: 'devices' kobject: '0:100' (000000004409e525): kobject_uevent_env kobject: '0:100' (000000004409e525): fill_kobj_path: path = '/devices/virtual/bdi/0:100' protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 kobject: 'loop0' (00000000a7e2f38c): kobject_uevent_env kobject: 'loop0' (00000000a7e2f38c): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop0' (00000000a7e2f38c): kobject_uevent_env kobject: 'loop0' (00000000a7e2f38c): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop0' (00000000a7e2f38c): kobject_uevent_env kobject: 'loop0' (00000000a7e2f38c): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop0' (00000000a7e2f38c): kobject_uevent_env kobject: 'loop0' (00000000a7e2f38c): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'kvm' (000000001db6cde0): kobject_uevent_env kobject: 'kvm' (000000001db6cde0): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'kvm' (000000001db6cde0): kobject_uevent_env kobject: 'kvm' (000000001db6cde0): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'loop0' (00000000a7e2f38c): kobject_uevent_env kobject: 'loop0' (00000000a7e2f38c): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'kvm' (000000001db6cde0): kobject_uevent_env kobject: 'kvm' (000000001db6cde0): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'kvm' (000000001db6cde0): kobject_uevent_env kobject: 'kvm' (000000001db6cde0): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'kvm' (000000001db6cde0): kobject_uevent_env kobject: 'loop0' (00000000a7e2f38c): kobject_uevent_env kobject: 'loop0' (00000000a7e2f38c): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'kvm' (000000001db6cde0): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'kvm' (000000001db6cde0): kobject_uevent_env kobject: 'kvm' (000000001db6cde0): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'loop0' (00000000a7e2f38c): kobject_uevent_env kobject: 'loop0' (00000000a7e2f38c): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'kvm' (000000001db6cde0): kobject_uevent_env kobject: 'kvm' (000000001db6cde0): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'kvm' (000000001db6cde0): kobject_uevent_env kobject: 'kvm' (000000001db6cde0): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'kvm' (000000001db6cde0): kobject_uevent_env kobject: 'kvm' (000000001db6cde0): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'kvm' (000000001db6cde0): kobject_uevent_env kobject: 'kvm' (000000001db6cde0): fill_kobj_path: path = '/devices/virtual/misc/kvm' kobject: 'loop0' (00000000a7e2f38c): kobject_uevent_env kobject: 'loop0' (00000000a7e2f38c): fill_kobj_path: path = '/devices/virtual/block/loop0'