audit: type=1400 audit(1556165327.679:210): avc: denied { associate } for pid=22145 comm="syz-executor.4" name="file1" scontext=unconfined_u:object_r:unlabeled_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=filesystem permissive=1 overlayfs: './file0' not a directory ====================================================== WARNING: possible circular locking dependency detected 4.14.113 #3 Not tainted ------------------------------------------------------ syz-executor.4/22205 is trying to acquire lock: (sb_writers#6){.+.+}, at: [] sb_start_write include/linux/fs.h:1545 [inline] (sb_writers#6){.+.+}, at: [] mnt_want_write+0x3f/0xb0 fs/namespace.c:386 but task is already holding lock: (&ovl_i_mutex_dir_key[depth]){++++}, at: [] inode_lock include/linux/fs.h:715 [inline] (&ovl_i_mutex_dir_key[depth]){++++}, at: [] do_last fs/namei.c:3328 [inline] (&ovl_i_mutex_dir_key[depth]){++++}, at: [] path_openat+0xfab/0x3f70 fs/namei.c:3566 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&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:725 [inline] do_last fs/namei.c:3330 [inline] path_openat+0x191e/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+0x6d2/0x1dd0 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+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #3 (&sig->cred_guard_mutex){+.+.}: 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 lock_trace+0x44/0xc0 fs/proc/base.c:407 proc_pid_stack+0x113/0x250 fs/proc/base.c:457 proc_single_show+0xf6/0x160 fs/proc/base.c:761 traverse+0x325/0x890 fs/seq_file.c:111 seq_read+0xa00/0x12a0 fs/seq_file.c:192 do_loop_readv_writev fs/read_write.c:694 [inline] do_loop_readv_writev fs/read_write.c:681 [inline] do_iter_read+0x3e7/0x5b0 fs/read_write.c:918 vfs_readv+0xd3/0x130 fs/read_write.c:980 do_preadv+0x15d/0x200 fs/read_write.c:1064 SYSC_preadv fs/read_write.c:1114 [inline] SyS_preadv+0x31/0x40 fs/read_write.c:1109 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #2 (&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+0xc1/0x12a0 fs/seq_file.c:165 proc_reg_read+0xfd/0x180 fs/proc/inode.c:217 do_loop_readv_writev fs/read_write.c:694 [inline] do_loop_readv_writev fs/read_write.c:681 [inline] do_iter_read+0x3e7/0x5b0 fs/read_write.c:918 vfs_readv+0xd3/0x130 fs/read_write.c:980 kernel_readv fs/splice.c:361 [inline] default_file_splice_read+0x421/0x7b0 fs/splice.c:416 do_splice_to+0x108/0x170 fs/splice.c:880 do_splice fs/splice.c:1173 [inline] SYSC_splice fs/splice.c:1402 [inline] SyS_splice+0xfcb/0x13e0 fs/splice.c:1382 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #1 (&pipe->mutex/1){+.+.}: 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 pipe_lock_nested fs/pipe.c:67 [inline] pipe_lock+0x63/0x80 fs/pipe.c:75 iter_file_splice_write+0x15e/0xae0 fs/splice.c:699 do_splice_from fs/splice.c:851 [inline] do_splice fs/splice.c:1147 [inline] SYSC_splice fs/splice.c:1402 [inline] SyS_splice+0xd81/0x13e0 fs/splice.c:1382 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #0 (sb_writers#6){.+.+}: 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+0x2c89/0x45e0 kernel/locking/lockdep.c:3487 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:1545 [inline] mnt_want_write+0x3f/0xb0 fs/namespace.c:386 ovl_want_write+0x76/0xa0 fs/overlayfs/util.c:25 ovl_create_object+0x79/0x1e0 fs/overlayfs/dir.c:538 ovl_create+0x28/0x30 fs/overlayfs/dir.c:563 lookup_open+0x11b1/0x1870 fs/namei.c:3240 do_last fs/namei.c:3331 [inline] path_openat+0xfca/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1065 SYSC_open fs/open.c:1083 [inline] SyS_open fs/open.c:1078 [inline] SYSC_creat fs/open.c:1123 [inline] SyS_creat+0x27/0x30 fs/open.c:1121 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 other info that might help us debug this: Chain exists of: sb_writers#6 --> &sig->cred_guard_mutex --> &ovl_i_mutex_dir_key[depth] Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ovl_i_mutex_dir_key[depth]); lock(&sig->cred_guard_mutex); lock(&ovl_i_mutex_dir_key[depth]); lock(sb_writers#6); *** DEADLOCK *** 2 locks held by syz-executor.4/22205: #0: (sb_writers#18){.+.+}, at: [] sb_start_write include/linux/fs.h:1545 [inline] #0: (sb_writers#18){.+.+}, at: [] mnt_want_write+0x3f/0xb0 fs/namespace.c:386 #1: (&ovl_i_mutex_dir_key[depth]){++++}, at: [] inode_lock include/linux/fs.h:715 [inline] #1: (&ovl_i_mutex_dir_key[depth]){++++}, at: [] do_last fs/namei.c:3328 [inline] #1: (&ovl_i_mutex_dir_key[depth]){++++}, at: [] path_openat+0xfab/0x3f70 fs/namei.c:3566 stack backtrace: CPU: 0 PID: 22205 Comm: syz-executor.4 Not tainted 4.14.113 #3 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+0x138/0x19c lib/dump_stack.c:53 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+0x2c89/0x45e0 kernel/locking/lockdep.c:3487 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:1545 [inline] mnt_want_write+0x3f/0xb0 fs/namespace.c:386 ovl_want_write+0x76/0xa0 fs/overlayfs/util.c:25 ovl_create_object+0x79/0x1e0 fs/overlayfs/dir.c:538 ovl_create+0x28/0x30 fs/overlayfs/dir.c:563 lookup_open+0x11b1/0x1870 fs/namei.c:3240 do_last fs/namei.c:3331 [inline] path_openat+0xfca/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1065 SYSC_open fs/open.c:1083 [inline] SyS_open fs/open.c:1078 [inline] SYSC_creat fs/open.c:1123 [inline] SyS_creat+0x27/0x30 fs/open.c:1121 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x458d99 RSP: 002b:00007f3263433c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000458d99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000080 RBP: 000000000073c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f32634346d4 R13: 00000000004bf2e4 R14: 00000000004d0468 R15: 00000000ffffffff kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop3' (ffff8880a49d2160): kobject_uevent_env kobject: 'loop3' (ffff8880a49d2160): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop3' (ffff8880a49d2160): kobject_uevent_env kobject: 'loop3' (ffff8880a49d2160): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop3' (ffff8880a49d2160): kobject_uevent_env kobject: 'loop3' (ffff8880a49d2160): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' net_ratelimit: 22 callbacks suppressed protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 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: 'loop3' (ffff8880a49d2160): kobject_uevent_env kobject: 'loop3' (ffff8880a49d2160): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 kobject: 'loop3' (ffff8880a49d2160): kobject_uevent_env kobject: 'loop3' (ffff8880a49d2160): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' SELinux: unrecognized netlink message: protocol=0 nlmsg_type=46317 sclass=netlink_route_socket pig=22425 comm=syz-executor.5 kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop3' (ffff8880a49d2160): kobject_uevent_env kobject: 'loop3' (ffff8880a49d2160): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop3' (ffff8880a49d2160): kobject_uevent_env kobject: 'loop3' (ffff8880a49d2160): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop3' (ffff8880a49d2160): kobject_uevent_env kobject: 'loop3' (ffff8880a49d2160): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop3' (ffff8880a49d2160): kobject_uevent_env kobject: 'loop3' (ffff8880a49d2160): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop3' (ffff8880a49d2160): kobject_uevent_env kobject: 'loop3' (ffff8880a49d2160): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop3' (ffff8880a49d2160): kobject_uevent_env kobject: 'loop3' (ffff8880a49d2160): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop3' (ffff8880a49d2160): kobject_uevent_env kobject: 'loop3' (ffff8880a49d2160): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop3' (ffff8880a49d2160): kobject_uevent_env kobject: 'loop3' (ffff8880a49d2160): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop3' (ffff8880a49d2160): kobject_uevent_env kobject: 'loop3' (ffff8880a49d2160): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' net_ratelimit: 22 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 kobject: 'loop3' (ffff8880a49d2160): kobject_uevent_env kobject: 'loop3' (ffff8880a49d2160): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4' protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 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: 'loop3' (ffff8880a49d2160): kobject_uevent_env kobject: 'loop3' (ffff8880a49d2160): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (ffff8880a4a30a60): kobject_uevent_env kobject: 'loop4' (ffff8880a4a30a60): fill_kobj_path: path = '/devices/virtual/block/loop4'