====================================================== WARNING: possible circular locking dependency detected 5.0.0-rc4+ #55 Not tainted ------------------------------------------------------ syz-executor0/18830 is trying to acquire lock: 0000000055efc0e2 (&ovl_i_mutex_dir_key[depth]#2){++++}, at: inode_lock_shared include/linux/fs.h:767 [inline] 0000000055efc0e2 (&ovl_i_mutex_dir_key[depth]#2){++++}, at: lookup_slow+0x4a/0x80 fs/namei.c:1687 but task is already holding lock: 00000000f6a72106 (&sig->cred_guard_mutex){+.+.}, at: __do_sys_perf_event_open+0x9c3/0x2f00 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+0x12f/0x1670 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_stack+0x1e6/0x430 fs/proc/base.c:434 proc_single_show+0xf6/0x180 fs/proc/base.c:739 seq_read+0x4db/0x1130 fs/seq_file.c:229 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+0x175/0x1c0 fs/read_write.c:983 do_preadv+0x1c4/0x280 fs/read_write.c:1067 __do_sys_preadv fs/read_write.c:1117 [inline] __se_sys_preadv fs/read_write.c:1112 [inline] __x64_sys_preadv+0x9a/0xf0 fs/read_write.c:1112 do_syscall_64+0x1a3/0x800 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+0x12f/0x1670 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+0x175/0x1c0 fs/read_write.c:983 kernel_readv fs/splice.c:362 [inline] default_file_splice_read+0x50c/0xac0 fs/splice.c:417 do_splice_to+0x12a/0x190 fs/splice.c:880 splice_direct_to_actor+0x31b/0x9d0 fs/splice.c:957 do_splice_direct+0x2c7/0x420 fs/splice.c:1066 do_sendfile+0x61a/0xe60 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+0x1f8/0x240 fs/read_write.c:1483 do_syscall_64+0x1a3/0x800 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_do_remove+0x12d/0xee0 fs/overlayfs/dir.c:840 ovl_rmdir+0x1b/0x20 fs/overlayfs/dir.c:890 vfs_rmdir fs/namei.c:3879 [inline] vfs_rmdir+0x19c/0x470 fs/namei.c:3858 do_rmdir+0x474/0x580 fs/namei.c:3940 __do_sys_rmdir fs/namei.c:3958 [inline] __se_sys_rmdir fs/namei.c:3956 [inline] __x64_sys_rmdir+0x36/0x40 fs/namei.c:3956 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&ovl_i_mutex_dir_key[depth]#2){++++}: lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841 down_read+0x8d/0x120 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:767 [inline] lookup_slow+0x4a/0x80 fs/namei.c:1687 walk_component+0x8e5/0x26a0 fs/namei.c:1810 lookup_last fs/namei.c:2273 [inline] path_lookupat.isra.0+0x1f5/0xba0 fs/namei.c:2318 filename_lookup+0x27a/0x530 fs/namei.c:2348 kern_path+0x36/0x40 fs/namei.c:2434 create_local_trace_uprobe+0x93/0x610 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+0x20bf/0x3520 kernel/events/core.c:10074 perf_event_alloc kernel/events/core.c:10430 [inline] __do_sys_perf_event_open+0xbb5/0x2f00 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+0x1a3/0x800 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-executor0/18830: #0: 00000000f6a72106 (&sig->cred_guard_mutex){+.+.}, at: __do_sys_perf_event_open+0x9c3/0x2f00 kernel/events/core.c:10511 #1: 00000000ea40cdfe (&pmus_srcu){....}, at: perf_event_alloc.part.0+0x10c1/0x3520 kernel/events/core.c:10070 stack backtrace: CPU: 0 PID: 18830 Comm: syz-executor0 Not tainted 5.0.0-rc4+ #55 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+0x1db/0x2d0 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+0x3014/0x4a30 kernel/locking/lockdep.c:3338 lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841 down_read+0x8d/0x120 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:767 [inline] lookup_slow+0x4a/0x80 fs/namei.c:1687 walk_component+0x8e5/0x26a0 fs/namei.c:1810 lookup_last fs/namei.c:2273 [inline] path_lookupat.isra.0+0x1f5/0xba0 fs/namei.c:2318 filename_lookup+0x27a/0x530 fs/namei.c:2348 kern_path+0x36/0x40 fs/namei.c:2434 create_local_trace_uprobe+0x93/0x610 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+0x20bf/0x3520 kernel/events/core.c:10074 perf_event_alloc kernel/events/core.c:10430 [inline] __do_sys_perf_event_open+0xbb5/0x2f00 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+0x1a3/0x800 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:00007fe2817bcc78 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: 00007fe2817bd6d4 R13: 00000000004c443f R14: 00000000004d7a48 R15: 00000000ffffffff libceph: connect [d::]:6789 error -101 libceph: mon0 [d::]:6789 connect error kobject: 'loop2' (00000000760c4e14): kobject_uevent_env kobject: 'batman_adv' (00000000795632aa): kobject_uevent_env kobject: 'loop2' (00000000760c4e14): fill_kobj_path: path = '/devices/virtual/block/loop2' overlayfs: './file0' not a directory kobject: 'batman_adv' (00000000795632aa): kobject_uevent_env: filter function caused the event to drop! kobject: 'batman_adv' (00000000795632aa): kobject_cleanup, parent (null) kobject: 'batman_adv' (00000000795632aa): calling ktype release kobject: (00000000795632aa): dynamic_kobj_release kobject: 'batman_adv': free name kobject: 'rx-0' (0000000006382630): kobject_cleanup, parent 000000000178ac19 kobject: 'rx-0' (0000000006382630): auto cleanup 'remove' event kobject: 'rx-0' (0000000006382630): kobject_uevent_env libceph: connect [d::]:6789 error -101 libceph: mon0 [d::]:6789 connect error kobject: 'rx-0' (0000000006382630): fill_kobj_path: path = '/devices/virtual/net/nr0/queues/rx-0' kobject: 'loop3' (000000009e63c9a6): kobject_uevent_env kobject: 'rx-0' (0000000006382630): auto cleanup kobject_del kobject: 'loop3' (000000009e63c9a6): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'rx-0' (0000000006382630): calling ktype release kobject: 'rx-0': free name kobject: 'tx-0' (000000005e2a0962): kobject_cleanup, parent 000000000178ac19 kobject: 'tx-0' (000000005e2a0962): auto cleanup 'remove' event kobject: 'tx-0' (000000005e2a0962): kobject_uevent_env kobject: 'tx-0' (000000005e2a0962): fill_kobj_path: path = '/devices/virtual/net/nr0/queues/tx-0' kobject: 'tx-0' (000000005e2a0962): auto cleanup kobject_del kobject: 'tx-0' (000000005e2a0962): calling ktype release kobject: 'loop0' (00000000e1fcbfdc): kobject_uevent_env kobject: 'tx-0': free name kobject: 'queues' (000000000178ac19): kobject_cleanup, parent (null) kobject: 'queues' (000000000178ac19): calling ktype release kobject: 'loop0' (00000000e1fcbfdc): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'queues' (000000000178ac19): kset_release kobject: 'queues': free name kobject: 'nr0' (00000000bf6b7131): kobject_uevent_env kobject: 'nr0' (00000000bf6b7131): fill_kobj_path: path = '/devices/virtual/net/nr0' overlayfs: failed to resolve './file1': -2 kobject: 'loop3' (000000009e63c9a6): kobject_uevent_env kobject: 'nr0' (00000000bf6b7131): kobject_cleanup, parent (null) kobject: 'nr0' (00000000bf6b7131): calling ktype release kobject: 'nr0': free name kobject: 'loop3' (000000009e63c9a6): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'nr0' (00000000dab19069): kobject_add_internal: parent: 'net', set: 'devices' kobject: 'loop1' (000000006351859c): kobject_uevent_env kobject: 'loop1' (000000006351859c): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'nr0' (00000000dab19069): kobject_uevent_env kobject: 'nr0' (00000000dab19069): fill_kobj_path: path = '/devices/virtual/net/nr0' kobject: 'loop0' (00000000e1fcbfdc): kobject_uevent_env kobject: 'queues' (000000004057a464): kobject_add_internal: parent: 'nr0', set: '' kobject: 'loop0' (00000000e1fcbfdc): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'queues' (000000004057a464): kobject_uevent_env kobject: 'queues' (000000004057a464): kobject_uevent_env: filter function caused the event to drop! kobject: 'rx-0' (000000007856bc80): kobject_add_internal: parent: 'queues', set: 'queues' kobject: 'rx-0' (000000007856bc80): kobject_uevent_env kobject: 'rx-0' (000000007856bc80): fill_kobj_path: path = '/devices/virtual/net/nr0/queues/rx-0' kobject: 'tx-0' (000000001a3d4a3a): kobject_add_internal: parent: 'queues', set: 'queues' kobject: 'tx-0' (000000001a3d4a3a): kobject_uevent_env kobject: 'tx-0' (000000001a3d4a3a): fill_kobj_path: path = '/devices/virtual/net/nr0/queues/tx-0' kobject: 'batman_adv' (00000000e0bdb9ed): kobject_add_internal: parent: 'nr0', set: '' kobject: 'batman_adv' (00000000e0bdb9ed): kobject_uevent_env kobject: 'batman_adv' (00000000e0bdb9ed): kobject_uevent_env: filter function caused the event to drop! kobject: 'batman_adv' (00000000e0bdb9ed): kobject_cleanup, parent (null) kobject: 'batman_adv' (00000000e0bdb9ed): calling ktype release kobject: (00000000e0bdb9ed): dynamic_kobj_release kobject: 'batman_adv': free name kobject: 'rx-0' (000000007856bc80): kobject_cleanup, parent 000000004057a464 kobject: 'rx-0' (000000007856bc80): auto cleanup 'remove' event kobject: 'rx-0' (000000007856bc80): kobject_uevent_env kobject: 'rx-0' (000000007856bc80): fill_kobj_path: path = '/devices/virtual/net/nr0/queues/rx-0' kobject: 'rx-0' (000000007856bc80): auto cleanup kobject_del kobject: 'loop0' (00000000e1fcbfdc): kobject_uevent_env kobject: 'rx-0' (000000007856bc80): calling ktype release kobject: 'loop0' (00000000e1fcbfdc): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'rx-0': free name kobject: 'tx-0' (000000001a3d4a3a): kobject_cleanup, parent 000000004057a464 kobject: 'tx-0' (000000001a3d4a3a): auto cleanup 'remove' event kobject: 'tx-0' (000000001a3d4a3a): kobject_uevent_env kobject: 'tx-0' (000000001a3d4a3a): fill_kobj_path: path = '/devices/virtual/net/nr0/queues/tx-0' kobject: 'tx-0' (000000001a3d4a3a): auto cleanup kobject_del kobject: 'tx-0' (000000001a3d4a3a): calling ktype release kobject: 'tx-0': free name kobject: 'queues' (000000004057a464): kobject_cleanup, parent (null) kobject: 'queues' (000000004057a464): calling ktype release kobject: 'queues' (000000004057a464): kset_release kobject: 'queues': free name kobject: 'nr0' (00000000dab19069): kobject_uevent_env kobject: 'nr0' (00000000dab19069): fill_kobj_path: path = '/devices/virtual/net/nr0' kobject: 'nr0' (00000000dab19069): kobject_cleanup, parent (null) kobject: 'nr0' (00000000dab19069): calling ktype release kobject: 'nr0': free name kobject: 'loop1' (000000006351859c): kobject_uevent_env kobject: 'loop1' (000000006351859c): fill_kobj_path: path = '/devices/virtual/block/loop1' libceph: connect [d::]:6789 error -101 libceph: mon0 [d::]:6789 connect error kobject: 'loop0' (00000000e1fcbfdc): kobject_uevent_env kobject: 'loop0' (00000000e1fcbfdc): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop1' (000000006351859c): kobject_uevent_env kobject: 'loop1' (000000006351859c): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop0' (00000000e1fcbfdc): kobject_uevent_env kobject: 'loop0' (00000000e1fcbfdc): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop3' (000000009e63c9a6): kobject_uevent_env kobject: 'loop3' (000000009e63c9a6): fill_kobj_path: path = '/devices/virtual/block/loop3' libceph: connect [d::]:6789 error -101 libceph: mon0 [d::]:6789 connect error libceph: connect [d::]:6789 error -101 libceph: mon0 [d::]:6789 connect error libceph: connect [d::]:6789 error -101 libceph: mon0 [d::]:6789 connect error libceph: connect [d::]:6789 error -101 libceph: mon0 [d::]:6789 connect error libceph: connect [d::]:6789 error -101 libceph: mon0 [d::]:6789 connect error libceph: connect [d::]:6789 error -101 libceph: mon0 [d::]:6789 connect error libceph: connect [d::]:6789 error -101 libceph: mon0 [d::]:6789 connect error