overlayfs: fs on './file0' does not support file handles, falling back to index=off. ====================================================== WARNING: possible circular locking dependency detected 4.14.211-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.2/925 is trying to acquire lock: (&oi->lock){+.+.}, at: [] ovl_copy_up_start+0x40/0xe0 fs/overlayfs/util.c:318 but task is already holding lock: (sb_writers#3){.+.+}, at: [] sb_start_write include/linux/fs.h:1549 [inline] (sb_writers#3){.+.+}, at: [] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (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+0x64/0x260 fs/super.c:1342 sb_start_write include/linux/fs.h:1549 [inline] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 ovl_do_remove+0x67/0xb90 fs/overlayfs/dir.c:759 vfs_rmdir.part.0+0x144/0x390 fs/namei.c:3908 vfs_rmdir fs/namei.c:3893 [inline] do_rmdir+0x334/0x3c0 fs/namei.c:3968 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #1 (&ovl_i_mutex_dir_key[depth]){++++}: down_read+0x36/0x80 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:729 [inline] lookup_slow+0x129/0x400 fs/namei.c:1674 lookup_one_len_unlocked+0x3a0/0x410 fs/namei.c:2595 ovl_lower_positive+0x184/0x345 fs/overlayfs/namei.c:783 ovl_rename+0x47c/0xf10 fs/overlayfs/dir.c:968 vfs_rename+0x560/0x1820 fs/namei.c:4496 SYSC_renameat2 fs/namei.c:4644 [inline] SyS_renameat2+0x95b/0xad0 fs/namei.c:4533 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #0 (&oi->lock){+.+.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 ovl_copy_up_start+0x40/0xe0 fs/overlayfs/util.c:318 ovl_copy_up_one+0x21f/0x910 fs/overlayfs/copy_up.c:630 ovl_copy_up_flags+0xd5/0x120 fs/overlayfs/copy_up.c:685 ovl_rename+0x164/0xf10 fs/overlayfs/dir.c:939 vfs_rename+0x560/0x1820 fs/namei.c:4496 SYSC_renameat2 fs/namei.c:4644 [inline] SyS_renameat2+0x95b/0xad0 fs/namei.c:4533 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: &oi->lock --> &ovl_i_mutex_dir_key[depth] --> sb_writers#3 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_writers#3); lock(&ovl_i_mutex_dir_key[depth]); lock(sb_writers#3); lock(&oi->lock); *** DEADLOCK *** 7 locks held by syz-executor.2/925: #0: (sb_writers#15){.+.+}, at: [] sb_start_write include/linux/fs.h:1549 [inline] #0: (sb_writers#15){.+.+}, at: [] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 #1: (&type->s_vfs_rename_key#2){+.+.}, at: [] lock_rename+0x54/0x280 fs/namei.c:2889 #2: (&ovl_i_mutex_dir_key[depth]#2/1){+.+.}, at: [] inode_lock_nested include/linux/fs.h:754 [inline] #2: (&ovl_i_mutex_dir_key[depth]#2/1){+.+.}, at: [] lock_rename+0x132/0x280 fs/namei.c:2900 #3: (&ovl_i_mutex_dir_key[depth]#2/2){+.+.}, at: [] inode_lock_nested include/linux/fs.h:754 [inline] #3: (&ovl_i_mutex_dir_key[depth]#2/2){+.+.}, at: [] lock_rename+0x166/0x280 fs/namei.c:2901 #4: (&ovl_i_mutex_key[depth]){+.+.}, at: [] inode_lock include/linux/fs.h:719 [inline] #4: (&ovl_i_mutex_key[depth]){+.+.}, at: [] lock_two_nondirectories+0xca/0xf0 fs/inode.c:990 #5: (&ovl_i_mutex_key[depth]/4){+.+.}, at: [] inode_lock_nested include/linux/fs.h:754 [inline] #5: (&ovl_i_mutex_key[depth]/4){+.+.}, at: [] lock_two_nondirectories+0xb2/0xf0 fs/inode.c:992 #6: (sb_writers#3){.+.+}, at: [] sb_start_write include/linux/fs.h:1549 [inline] #6: (sb_writers#3){.+.+}, at: [] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 stack backtrace: CPU: 1 PID: 925 Comm: syz-executor.2 Not tainted 4.14.211-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.constprop.0.cold+0x2d7/0x41e 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+0x2e0e/0x3f20 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+0xc4/0x1310 kernel/locking/mutex.c:893 ovl_copy_up_start+0x40/0xe0 fs/overlayfs/util.c:318 ovl_copy_up_one+0x21f/0x910 fs/overlayfs/copy_up.c:630 ovl_copy_up_flags+0xd5/0x120 fs/overlayfs/copy_up.c:685 ovl_rename+0x164/0xf10 fs/overlayfs/dir.c:939 vfs_rename+0x560/0x1820 fs/namei.c:4496 SYSC_renameat2 fs/namei.c:4644 [inline] SyS_renameat2+0x95b/0xad0 fs/namei.c:4533 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45e0f9 RSP: 002b:00007f1329d99c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 000000000045e0f9 RDX: 0000000000000000 RSI: 0000000020000440 RDI: 0000000020000100 RBP: 000000000119bfb8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007fff0b5ae47f R14: 00007f1329d9a9c0 R15: 000000000119bf8c overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. hfsplus: unable to find HFS+ superblock overlayfs: fs on './file0' does not support file handles, falling back to index=off. nla_parse: 6 callbacks suppressed netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'. AppArmor: change_hat: Invalid input, NULL hat and NULL magic AppArmor: change_hat: Invalid input, NULL hat and NULL magic overlayfs: missing 'lowerdir' overlayfs: missing 'lowerdir' overlayfs: filesystem on './bus' not supported as upperdir AppArmor: change_hat: Invalid input, NULL hat and NULL magic overlayfs: missing 'lowerdir' AppArmor: change_hat: Invalid input, NULL hat and NULL magic overlayfs: missing 'lowerdir' overlayfs: missing 'lowerdir' overlayfs: missing 'lowerdir' overlayfs: missing 'lowerdir' overlayfs: missing 'lowerdir' overlayfs: missing 'lowerdir' overlayfs: missing 'lowerdir' overlayfs: missing 'lowerdir' overlayfs: missing 'lowerdir' overlayfs: missing 'lowerdir' overlayfs: missing 'lowerdir' overlayfs: upperdir is in-use by another mount, mount with '-o index=off' to override exclusive upperdir protection.