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. ====================================================== WARNING: possible circular locking dependency detected 4.14.307-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/12671 is trying to acquire lock: (&ovl_i_mutex_dir_key[depth]){++++}, 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_do_remove+0x67/0xb90 fs/overlayfs/dir.c:759 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 -> #0 (&ovl_i_mutex_dir_key[depth]){++++}: BTRFS: device fsid 24c7a497-3402-47dd-bef8-82358f5f30e0 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 down_write_killable+0x37/0xb0 kernel/locking/rwsem.c:68 devid 1 transid 8 /dev/loop4 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_rename+0x57d/0xe50 fs/overlayfs/dir.c:959 vfs_rename+0x560/0x1820 fs/namei.c:4498 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 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]); lock(sb_writers#3); lock(&ovl_i_mutex_dir_key[depth]); *** DEADLOCK *** 6 locks held by syz-executor.1/12671: #0: (sb_writers#21){.+.+}, at: [] sb_start_write include/linux/fs.h:1551 [inline] #0: (sb_writers#21){.+.+}, at: [] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 #1: (&type->s_vfs_rename_key#3){+.+.}, 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_dir_key[depth]#2){++++}, at: [] inode_lock include/linux/fs.h:719 [inline] #4: (&ovl_i_mutex_dir_key[depth]#2){++++}, at: [] vfs_rename+0xbd8/0x1820 fs/namei.c:4472 #5: (sb_writers#3){.+.+}, at: [] sb_start_write include/linux/fs.h:1551 [inline] #5: (sb_writers#3){.+.+}, at: [] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 stack backtrace: CPU: 0 PID: 12671 Comm: syz-executor.1 Not tainted 4.14.307-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023 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_rename+0x57d/0xe50 fs/overlayfs/dir.c:959 vfs_rename+0x560/0x1820 fs/namei.c:4498 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 RIP: 0033:0x7fbe95c830f9 RSP: 002b:00007fbe941f5168 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 00007fbe95da2f80 RCX: 00007fbe95c830f9 RDX: 0000000000000000 RSI: 0000000020000440 RDI: 0000000020000100 RBP: 00007fbe95cdeae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc53af9ecf R14: 00007fbe941f5300 R15: 0000000000022000 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. BTRFS info (device loop4): using free space tree BTRFS info (device loop4): has skinny extents 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. 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. 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. 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. overlayfs: fs on './file0' does not support file handles, falling back to index=off. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.4'. 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. 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. 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. 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. 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. overlayfs: fs on './file0' does not support file handles, falling back to index=off. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.1'. 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. 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: 12 bytes leftover after parsing attributes in process `syz-executor.2'. overlayfs: fs on './file0' does not support file handles, falling back to index=off. BTRFS info (device loop4): using free space tree overlayfs: fs on './file0' does not support file handles, falling back to index=off. BTRFS info (device loop4): has skinny extents 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: 12 bytes leftover after parsing attributes in process `syz-executor.4'. 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. 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: 12 bytes leftover after parsing attributes in process `syz-executor.1'. 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. 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: 20 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.2'. BTRFS info (device loop4): using free space tree device vlan2 entered promiscuous mode BTRFS info (device loop4): has skinny extents device bridge1 entered promiscuous mode 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: 20 bytes leftover after parsing attributes in process `syz-executor.5'. device vlan3 entered promiscuous mode device bridge2 entered promiscuous mode device vlan4 entered promiscuous mode device bridge3 entered promiscuous mode BTRFS info (device loop4): using free space tree BTRFS info (device loop4): has skinny extents overlayfs: fs on '.' does not support file handles, falling back to index=off. overlayfs: upper fs needs to support d_type. device vlan5 entered promiscuous mode device bridge4 entered promiscuous mode overlayfs: upper fs does not support tmpfile. device gretap0 entered promiscuous mode nla_parse: 6 callbacks suppressed netlink: 5 bytes leftover after parsing attributes in process `syz-executor.0'. 0猉功D龌: renamed from gretap0 device c0猉功D龌 left promiscuous mode netlink: 9 bytes leftover after parsing attributes in process `syz-executor.1'. device gretap0 entered promiscuous mode netlink: 5 bytes leftover after parsing attributes in process `syz-executor.1'. 0猉功D龌: renamed from gretap0 device c0猉功D龌 left promiscuous mode netlink: 9 bytes leftover after parsing attributes in process `syz-executor.4'. device gretap0 entered promiscuous mode netlink: 9 bytes leftover after parsing attributes in process `syz-executor.0'. device c0猉功D龌 entered promiscuous mode netlink: 5 bytes leftover after parsing attributes in process `syz-executor.4'. 0猉功D龌: renamed from gretap0 device c0猉功D龌 left promiscuous mode netlink: 5 bytes leftover after parsing attributes in process `syz-executor.0'. 1猉功D龌: renamed from c0猉功D龌 device c1猉功D龌 left promiscuous mode netlink: 9 bytes leftover after parsing attributes in process `syz-executor.0'. device c1猉功D龌 entered promiscuous mode netlink: 5 bytes leftover after parsing attributes in process `syz-executor.0'. 0猉功D龌: renamed from c1猉功D龌 device c0猉功D龌 left promiscuous mode netlink: 9 bytes leftover after parsing attributes in process `syz-executor.2'. device gretap0 entered promiscuous mode 0猉功D龌: renamed from gretap0 device c0猉功D龌 left promiscuous mode device c0猉功D龌 entered promiscuous mode 1猉功D龌: renamed from c0猉功D龌 device c1猉功D龌 left promiscuous mode device c0猉功D龌 entered promiscuous mode 1猉功D龌: renamed from c0猉功D龌 device c1猉功D龌 left promiscuous mode nla_parse: 5 callbacks suppressed netlink: 9 bytes leftover after parsing attributes in process `syz-executor.2'.