====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.2.562/7931 is trying to acquire lock: ffffffff8fd88028 (&subsys->su_mutex){+.+.}-{4:4}, at: configfs_rmdir+0x5ae/0x950 fs/configfs/dir.c:1556 but task is already holding lock: ffff8880781ce740 (&sb->s_type->i_mutex_key#27){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] ffff8880781ce740 (&sb->s_type->i_mutex_key#27){+.+.}-{4:4}, at: vfs_rmdir fs/namei.c:5366 [inline] ffff8880781ce740 (&sb->s_type->i_mutex_key#27){+.+.}-{4:4}, at: vfs_rmdir+0xed/0x8a0 fs/namei.c:5354 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&sb->s_type->i_mutex_key#27){+.+.}-{4:4}: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825 down_write+0x8b/0x1f0 kernel/locking/rwsem.c:1631 inode_lock include/linux/fs.h:1024 [inline] configfs_depend_item_unlocked+0xf3/0x6a0 fs/configfs/dir.c:1259 usbg_make_tpg+0x261/0x620 drivers/usb/gadget/function/f_tcm.c:1686 target_fabric_make_tpg+0xab/0x8c0 drivers/target/target_core_fabric_configfs.c:939 configfs_mkdir+0x51e/0xb70 fs/configfs/dir.c:1360 vfs_mkdir+0x361/0x850 fs/namei.c:5276 filename_mkdirat+0x48b/0x5e0 fs/namei.c:5309 __do_sys_mkdir fs/namei.c:5336 [inline] __se_sys_mkdir fs/namei.c:5333 [inline] __x64_sys_mkdir+0x6b/0x90 fs/namei.c:5333 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&opts->dep_lock){+.+.}-{4:4}: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821 usbg_make_tpg+0x1a4/0x620 drivers/usb/gadget/function/f_tcm.c:1678 target_fabric_make_tpg+0xab/0x8c0 drivers/target/target_core_fabric_configfs.c:939 configfs_mkdir+0x51e/0xb70 fs/configfs/dir.c:1360 vfs_mkdir+0x361/0x850 fs/namei.c:5276 filename_mkdirat+0x48b/0x5e0 fs/namei.c:5309 __do_sys_mkdir fs/namei.c:5336 [inline] __se_sys_mkdir fs/namei.c:5333 [inline] __x64_sys_mkdir+0x6b/0x90 fs/namei.c:5333 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (tpg_instances_lock){+.+.}-{4:4}: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821 usbg_make_tpg+0x10b/0x620 drivers/usb/gadget/function/f_tcm.c:1669 target_fabric_make_tpg+0xab/0x8c0 drivers/target/target_core_fabric_configfs.c:939 configfs_mkdir+0x51e/0xb70 fs/configfs/dir.c:1360 vfs_mkdir+0x361/0x850 fs/namei.c:5276 filename_mkdirat+0x48b/0x5e0 fs/namei.c:5309 __do_sys_mkdir fs/namei.c:5336 [inline] __se_sys_mkdir fs/namei.c:5333 [inline] __x64_sys_mkdir+0x6b/0x90 fs/namei.c:5333 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&subsys->su_mutex){+.+.}-{4:4}: check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3165 check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x136c/0x1a40 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821 configfs_rmdir+0x5ae/0x950 fs/configfs/dir.c:1556 vfs_rmdir fs/namei.c:5381 [inline] vfs_rmdir+0x328/0x8a0 fs/namei.c:5354 filename_rmdir+0x31a/0x5c0 fs/namei.c:5438 __do_sys_rmdir fs/namei.c:5461 [inline] __se_sys_rmdir fs/namei.c:5458 [inline] __x64_sys_rmdir+0x46/0x70 fs/namei.c:5458 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &subsys->su_mutex --> &opts->dep_lock --> &sb->s_type->i_mutex_key#27 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#27); lock(&opts->dep_lock); lock(&sb->s_type->i_mutex_key#27); lock(&subsys->su_mutex); *** DEADLOCK *** 3 locks held by syz.2.562/7931: #0: ffff88801e3f2450 (sb_writers#17){.+.+}-{0:0}, at: filename_rmdir+0x1ff/0x5c0 fs/namei.c:5427 #1: ffff88804c438600 (&sb->s_type->i_mutex_key#7/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline] #1: ffff88804c438600 (&sb->s_type->i_mutex_key#7/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline] #1: ffff88804c438600 (&sb->s_type->i_mutex_key#7/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline] #1: ffff88804c438600 (&sb->s_type->i_mutex_key#7/1){+.+.}-{4:4}, at: filename_rmdir+0x258/0x5c0 fs/namei.c:5431 #2: ffff8880781ce740 (&sb->s_type->i_mutex_key#27){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #2: ffff8880781ce740 (&sb->s_type->i_mutex_key#27){+.+.}-{4:4}, at: vfs_rmdir fs/namei.c:5366 [inline] #2: ffff8880781ce740 (&sb->s_type->i_mutex_key#27){+.+.}-{4:4}, at: vfs_rmdir+0xed/0x8a0 fs/namei.c:5354 stack backtrace: CPU: 1 UID: 0 PID: 7931 Comm: syz.2.562 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_circular_bug.cold+0x178/0x1c7 kernel/locking/lockdep.c:2043 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2175 check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3165 check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x136c/0x1a40 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821 configfs_rmdir+0x5ae/0x950 fs/configfs/dir.c:1556 vfs_rmdir fs/namei.c:5381 [inline] vfs_rmdir+0x328/0x8a0 fs/namei.c:5354 filename_rmdir+0x31a/0x5c0 fs/namei.c:5438 __do_sys_rmdir fs/namei.c:5461 [inline] __se_sys_rmdir fs/namei.c:5458 [inline] __x64_sys_rmdir+0x46/0x70 fs/namei.c:5458 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff70d79e019 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff70e715028 EFLAGS: 00000246 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 00007ff70da26090 RCX: 00007ff70d79e019 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000280 RBP: 00007ff70d83500c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff70da26128 R14: 00007ff70da26090 R15: 00007ffdf7219578