====================================================== WARNING: possible circular locking dependency detected 6.6.0-rc7-syzkaller-00137-g750b95887e56 #0 Not tainted ------------------------------------------------------ syz-executor.4/31615 is trying to acquire lock: ffff88814ba8c410 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:403 but task is already holding lock: ffff88803cc152d0 (&ovl_i_mutex_dir_key[depth]#2/4){+.+.}-{3:3}, at: vfs_rename+0x5eb/0xde0 fs/namei.c:4833 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&ovl_i_mutex_dir_key[depth]#2/4){+.+.}-{3:3}: down_write_nested+0x3d/0x50 kernel/locking/rwsem.c:1689 vfs_rename+0x5eb/0xde0 fs/namei.c:4833 do_renameat2+0xd5a/0x1390 fs/namei.c:5013 __do_sys_rename fs/namei.c:5059 [inline] __se_sys_rename fs/namei.c:5057 [inline] __x64_sys_rename+0x86/0x90 fs/namei.c:5057 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #3 (&ovl_i_mutex_dir_key[depth]#2){++++}-{3:3}: down_read+0xb1/0xa40 kernel/locking/rwsem.c:1520 inode_lock_shared include/linux/fs.h:812 [inline] lookup_slow+0x45/0x70 fs/namei.c:1710 walk_component+0x2d0/0x400 fs/namei.c:2002 lookup_last fs/namei.c:2459 [inline] path_lookupat+0x16f/0x450 fs/namei.c:2483 filename_lookup+0x255/0x610 fs/namei.c:2512 kern_path+0x35/0x50 fs/namei.c:2610 lookup_bdev+0xc5/0x290 block/bdev.c:926 resume_store+0x1a0/0x710 kernel/power/hibernate.c:1177 kernfs_fop_write_iter+0x3a6/0x4f0 fs/kernfs/file.c:334 do_iter_write+0x84f/0xde0 fs/read_write.c:860 iter_file_splice_write+0x86d/0x1010 fs/splice.c:736 do_splice_from fs/splice.c:933 [inline] direct_splice_actor+0xea/0x1c0 fs/splice.c:1142 splice_direct_to_actor+0x376/0x9e0 fs/splice.c:1088 do_splice_direct+0x2ac/0x3f0 fs/splice.c:1194 do_sendfile+0x623/0x1070 fs/read_write.c:1254 __do_sys_sendfile64 fs/read_write.c:1322 [inline] __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1308 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #2 (&of->mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x136/0xd60 kernel/locking/mutex.c:747 kernfs_seq_start+0x53/0x3a0 fs/kernfs/file.c:154 seq_read_iter+0x3d4/0xd10 fs/seq_file.c:225 call_read_iter include/linux/fs.h:1950 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x795/0xb00 fs/read_write.c:470 ksys_read+0x1a0/0x2c0 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #1 (&p->lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x136/0xd60 kernel/locking/mutex.c:747 seq_read_iter+0xb2/0xd10 fs/seq_file.c:182 call_read_iter include/linux/fs.h:1950 [inline] copy_splice_read+0x4c9/0x9c0 fs/splice.c:364 splice_direct_to_actor+0x2c4/0x9e0 fs/splice.c:1069 do_splice_direct+0x2ac/0x3f0 fs/splice.c:1194 do_sendfile+0x623/0x1070 fs/read_write.c:1254 __do_sys_sendfile64 fs/read_write.c:1322 [inline] __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1308 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (sb_writers#4){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5136 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1571 [inline] sb_start_write+0x4d/0x1c0 include/linux/fs.h:1646 mnt_want_write+0x3f/0x90 fs/namespace.c:403 ovl_rename+0x600/0x1620 fs/overlayfs/dir.c:1134 vfs_rename+0xaba/0xde0 fs/namei.c:4861 do_renameat2+0xd5a/0x1390 fs/namei.c:5013 __do_sys_rename fs/namei.c:5059 [inline] __se_sys_rename fs/namei.c:5057 [inline] __x64_sys_rename+0x86/0x90 fs/namei.c:5057 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Chain exists of: sb_writers#4 --> &ovl_i_mutex_dir_key[depth]#2 --> &ovl_i_mutex_dir_key[depth]#2/4 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ovl_i_mutex_dir_key[depth]#2/4); lock(&ovl_i_mutex_dir_key[depth]#2); lock(&ovl_i_mutex_dir_key[depth]#2/4); rlock(sb_writers#4); *** DEADLOCK *** 6 locks held by syz-executor.4/31615: #0: ffff88802f75e410 (sb_writers#21){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:403 #1: ffff88802f75e6f8 (&type->s_vfs_rename_key#7){+.+.}-{3:3}, at: lock_rename fs/namei.c:3050 [inline] #1: ffff88802f75e6f8 (&type->s_vfs_rename_key#7){+.+.}-{3:3}, at: do_renameat2+0x5b4/0x1390 fs/namei.c:4952 #2: ffff888035394160 (&ovl_i_mutex_dir_key[depth]#2/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:837 [inline] #2: ffff888035394160 (&ovl_i_mutex_dir_key[depth]#2/1){+.+.}-{3:3}, at: lock_two_directories+0xdb/0x150 fs/namei.c:3030 #3: ffff88803cc11e80 (&ovl_i_mutex_dir_key[depth]#2/2){+.+.}-{3:3}, at: lock_two_directories+0x107/0x150 #4: ffff88803cc12a20 (&ovl_i_mutex_dir_key[depth]#2){++++}-{3:3}, at: inode_lock_nested include/linux/fs.h:837 [inline] #4: ffff88803cc12a20 (&ovl_i_mutex_dir_key[depth]#2){++++}-{3:3}, at: lock_two_inodes+0x100/0x180 fs/inode.c:1127 #5: ffff88803cc152d0 (&ovl_i_mutex_dir_key[depth]#2/4){+.+.}-{3:3}, at: vfs_rename+0x5eb/0xde0 fs/namei.c:4833 stack backtrace: CPU: 0 PID: 31615 Comm: syz-executor.4 Not tainted 6.6.0-rc7-syzkaller-00137-g750b95887e56 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 check_noncircular+0x375/0x4a0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5136 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1571 [inline] sb_start_write+0x4d/0x1c0 include/linux/fs.h:1646 mnt_want_write+0x3f/0x90 fs/namespace.c:403 ovl_rename+0x600/0x1620 fs/overlayfs/dir.c:1134 vfs_rename+0xaba/0xde0 fs/namei.c:4861 do_renameat2+0xd5a/0x1390 fs/namei.c:5013 __do_sys_rename fs/namei.c:5059 [inline] __se_sys_rename fs/namei.c:5057 [inline] __x64_sys_rename+0x86/0x90 fs/namei.c:5057 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fe4b4e7cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe4b5b7a0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 00007fe4b4f9c050 RCX: 00007fe4b4e7cae9 RDX: 0000000000000000 RSI: 0000000020000440 RDI: 0000000020000100 RBP: 00007fe4b4ec847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007fe4b4f9c050 R15: 00007fff03822808