====================================================== WARNING: possible circular locking dependency detected 4.14.305-syzkaller #0 Not tainted ------------------------------------------------------ netlink: 24 bytes leftover after parsing attributes in process `syz-executor.2'. syz-executor.3/10198 is trying to acquire lock: (&ovl_i_mutex_dir_key[depth]#3){++++}, at: [] iterate_dir+0x387/0x5e0 fs/readdir.c:43 but task is already holding lock: (sb_writers#3){.+.+}, at: [] sb_start_write include/linux/fs.h:1551 [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: -> #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+0x64/0x260 fs/super.c:1342 sb_start_write include/linux/fs.h:1551 [inline] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 ovl_rename+0x11b/0xe50 fs/overlayfs/dir.c:935 vfs_rename+0x560/0x1820 fs/namei.c:4498 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.2'. SYSC_renameat2 fs/namei.c:4646 [inline] SyS_renameat2+0x95b/0xad0 fs/namei.c:4535 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x5e/0xd3 -> #0 (&ovl_i_mutex_dir_key[depth]#3){++++}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 down_write_killable+0x37/0xb0 kernel/locking/rwsem.c:68 iterate_dir+0x387/0x5e0 fs/readdir.c:43 ovl_dir_read fs/overlayfs/readdir.c:306 [inline] ovl_dir_read_merged+0x2c5/0x430 fs/overlayfs/readdir.c:365 ovl_check_empty_dir+0x6e/0x200 fs/overlayfs/readdir.c:870 ovl_check_empty_and_clear+0x72/0xe0 fs/overlayfs/dir.c:306 ovl_remove_and_whiteout fs/overlayfs/dir.c:647 [inline] ovl_do_remove+0x565/0xb90 fs/overlayfs/dir.c:775 vfs_rmdir.part.0+0x144/0x390 fs/namei.c:3910 vfs_rmdir fs/namei.c:3895 [inline] do_rmdir+0x334/0x3c0 fs/namei.c:3970 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x5e/0xd3 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_writers#3); lock(&ovl_i_mutex_dir_key[depth]#3); lock(sb_writers#3); lock(&ovl_i_mutex_dir_key[depth]#3); *** DEADLOCK *** 4 locks held by syz-executor.3/10198: #0: (sb_writers#15){.+.+}, at: [] sb_start_write include/linux/fs.h:1551 [inline] #0: (sb_writers#15){.+.+}, at: [] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 #1: (&ovl_i_mutex_dir_key[depth]#4/1){+.+.}, at: [] inode_lock_nested include/linux/fs.h:754 [inline] #1: (&ovl_i_mutex_dir_key[depth]#4/1){+.+.}, at: [] do_rmdir+0x1de/0x3c0 fs/namei.c:3958 #2: (&ovl_i_mutex_dir_key[depth]#5){+.+.}, at: [] inode_lock include/linux/fs.h:719 [inline] #2: (&ovl_i_mutex_dir_key[depth]#5){+.+.}, at: [] vfs_rmdir.part.0+0x5c/0x390 fs/namei.c:3899 #3: (sb_writers#3){.+.+}, at: [] sb_start_write include/linux/fs.h:1551 [inline] #3: (sb_writers#3){.+.+}, at: [] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 stack backtrace: CPU: 0 PID: 10198 Comm: syz-executor.3 Not tainted 4.14.305-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 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 down_write_killable+0x37/0xb0 kernel/locking/rwsem.c:68 iterate_dir+0x387/0x5e0 fs/readdir.c:43 ovl_dir_read fs/overlayfs/readdir.c:306 [inline] ovl_dir_read_merged+0x2c5/0x430 fs/overlayfs/readdir.c:365 ovl_check_empty_dir+0x6e/0x200 fs/overlayfs/readdir.c:870 ovl_check_empty_and_clear+0x72/0xe0 fs/overlayfs/dir.c:306 ovl_remove_and_whiteout fs/overlayfs/dir.c:647 [inline] ovl_do_remove+0x565/0xb90 fs/overlayfs/dir.c:775 vfs_rmdir.part.0+0x144/0x390 fs/namei.c:3910 vfs_rmdir fs/namei.c:3895 [inline] do_rmdir+0x334/0x3c0 fs/namei.c:3970 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x5e/0xd3 RIP: 0033:0x7f4335b840f9 RSP: 002b:00007f43340f6168 EFLAGS: 00000246 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 00007f4335ca3f80 RCX: 00007f4335b840f9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000180 RBP: 00007f4335bdfae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe7023caaf R14: 00007f43340f6300 R15: 0000000000022000 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'. ntfs: volume version 3.1. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. 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. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. ntfs: volume version 3.1. overlayfs: fs on 'file0' does not support file handles, falling back to index=off. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'. overlayfs: fs on './file0' does not support file handles, falling back to index=off. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. 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. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'. ntfs: volume version 3.1. ntfs: volume version 3.1. ntfs: volume version 3.1. __ntfs_warning: 12 callbacks suppressed ntfs: (device loop2): parse_options(): Option utf8 is no longer supported, using option nls=utf8. Please use option nls=utf8 in the future and make sure utf8 is compiled either as a module or into the kernel. ntfs: volume version 3.1. ntfs: (device loop2): parse_options(): Option utf8 is no longer supported, using option nls=utf8. Please use option nls=utf8 in the future and make sure utf8 is compiled either as a module or into the kernel. ntfs: volume version 3.1. BTRFS: device fsid 395ef67a-297e-477c-816d-cd80a5b93e5d devid 1 transid 8 /dev/loop1 BTRFS error (device loop1): unsupported checksum algorithm 2 BTRFS error (device loop1): superblock checksum mismatch BTRFS error (device loop1): open_ctree failed BTRFS error (device loop3): unsupported checksum algorithm 2 BTRFS error (device loop3): superblock checksum mismatch BTRFS error (device loop3): open_ctree failed BTRFS error (device loop3): unsupported checksum algorithm 2 BTRFS error (device loop3): superblock checksum mismatch BTRFS error (device loop3): open_ctree failed BTRFS error (device loop3): unsupported checksum algorithm 2 BTRFS error (device loop3): superblock checksum mismatch BTRFS error (device loop3): open_ctree failed BTRFS error (device loop1): unsupported checksum algorithm 2 BTRFS error (device loop1): superblock checksum mismatch BTRFS error (device loop1): open_ctree failed BTRFS error (device loop1): unsupported checksum algorithm 2 BTRFS error (device loop1): superblock checksum mismatch BTRFS error (device loop1): open_ctree failed BTRFS error (device loop1): unsupported checksum algorithm 2 BTRFS error (device loop1): superblock checksum mismatch BTRFS error (device loop1): open_ctree failed BTRFS error (device loop5): unsupported checksum algorithm 2 BTRFS error (device loop5): superblock checksum mismatch BTRFS error (device loop5): open_ctree failed BTRFS error (device loop3): unsupported checksum algorithm 2 BTRFS error (device loop3): superblock checksum mismatch BTRFS error (device loop3): open_ctree failed BTRFS error (device loop1): unsupported checksum algorithm 2 BTRFS error (device loop1): superblock checksum mismatch BTRFS error (device loop1): open_ctree failed BTRFS error (device loop5): unsupported checksum algorithm 2 BTRFS error (device loop5): superblock checksum mismatch BTRFS error (device loop5): open_ctree failed BTRFS error (device loop3): unsupported checksum algorithm 2 BTRFS error (device loop3): superblock checksum mismatch BTRFS error (device loop3): open_ctree failed BTRFS error (device loop1): unsupported checksum algorithm 2 BTRFS error (device loop1): superblock checksum mismatch BTRFS error (device loop1): open_ctree failed BTRFS error (device loop4): unsupported checksum algorithm 2 BTRFS error (device loop4): superblock checksum mismatch BTRFS error (device loop4): open_ctree failed BTRFS error (device loop4): unsupported checksum algorithm 2 BTRFS error (device loop4): superblock checksum mismatch BTRFS error (device loop4): open_ctree failed BTRFS error (device loop3): unsupported checksum algorithm 2 BTRFS error (device loop3): superblock checksum mismatch BTRFS error (device loop3): open_ctree failed BTRFS error (device loop1): unsupported checksum algorithm 2 BTRFS error (device loop1): superblock checksum mismatch BTRFS error (device loop1): open_ctree failed BTRFS error (device loop4): unsupported checksum algorithm 2 BTRFS error (device loop4): superblock checksum mismatch BTRFS error (device loop4): open_ctree failed BTRFS error (device loop4): unsupported checksum algorithm 2 BTRFS error (device loop4): superblock checksum mismatch BTRFS error (device loop4): open_ctree failed