====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.2.733/8147 is trying to acquire lock: ffffffff8f180ce0 (gadget_subsys.su_mutex){+.+.}-{4:4}, at: configfs_rmdir+0x5f0/0x950 fs/configfs/dir.c:1556 but task is already holding lock: ffff88805f373220 (&sb->s_type->i_mutex_key#23){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] ffff88805f373220 (&sb->s_type->i_mutex_key#23){++++}-{4:4}, at: vfs_rmdir+0xf8/0x6b0 fs/namei.c:5360 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&sb->s_type->i_mutex_key#23){++++}-{4:4}: down_write+0x3a/0x50 kernel/locking/rwsem.c:1631 inode_lock include/linux/fs.h:1024 [inline] configfs_depend_item_unlocked+0x153/0x420 fs/configfs/dir.c:1259 usbg_make_tpg+0x1f6/0x590 drivers/usb/gadget/function/f_tcm.c:1686 target_fabric_make_tpg+0xa8/0x6d0 drivers/target/target_core_fabric_configfs.c:939 configfs_mkdir+0x4f6/0x9e0 fs/configfs/dir.c:1360 vfs_mkdir+0x408/0x620 fs/namei.c:5270 filename_mkdirat+0x289/0x520 fs/namei.c:5303 __do_sys_mkdir fs/namei.c:5330 [inline] __se_sys_mkdir+0x34/0x150 fs/namei.c:5327 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x17b/0x530 arch/x86/entry/syscall_64.c:85 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&opts->dep_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/rtmutex_api.c:559 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:578 tcm_set_name+0x2b/0xd0 drivers/usb/gadget/function/f_tcm.c:2669 function_make+0x1a8/0x360 drivers/usb/gadget/configfs.c:636 configfs_mkdir+0x4f6/0x9e0 fs/configfs/dir.c:1360 vfs_mkdir+0x408/0x620 fs/namei.c:5270 filename_mkdirat+0x289/0x520 fs/namei.c:5303 __do_sys_mkdir fs/namei.c:5330 [inline] __se_sys_mkdir+0x34/0x150 fs/namei.c:5327 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x17b/0x530 arch/x86/entry/syscall_64.c:85 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (gadget_subsys.su_mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3181 [inline] check_prevs_add kernel/locking/lockdep.c:3300 [inline] validate_chain kernel/locking/lockdep.c:3924 [inline] __lock_acquire+0x15ff/0x2e40 kernel/locking/lockdep.c:5254 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5906 __mutex_lock_common kernel/locking/rtmutex_api.c:559 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:578 configfs_rmdir+0x5f0/0x950 fs/configfs/dir.c:1556 vfs_rmdir+0x3e9/0x6b0 fs/namei.c:5375 filename_rmdir+0x292/0x520 fs/namei.c:5432 __do_sys_rmdir fs/namei.c:5455 [inline] __se_sys_rmdir+0x2e/0x140 fs/namei.c:5452 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x17b/0x530 arch/x86/entry/syscall_64.c:85 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: gadget_subsys.su_mutex --> &opts->dep_lock --> &sb->s_type->i_mutex_key#23 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#23); lock(&opts->dep_lock); lock(&sb->s_type->i_mutex_key#23); lock(gadget_subsys.su_mutex); *** DEADLOCK *** locks held by syz.2.733/8147: 3, last CPU#0: #0: ffff88801bba8510 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494 #1: ffff8880402e62c8 (&default_group_class[depth - 1]#2/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline] #1: ffff8880402e62c8 (&default_group_class[depth - 1]#2/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline] #1: ffff8880402e62c8 (&default_group_class[depth - 1]#2/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline] #1: ffff8880402e62c8 (&default_group_class[depth - 1]#2/1){+.+.}-{4:4}, at: filename_rmdir+0x1cd/0x520 fs/namei.c:5425 #2: ffff88805f373220 (&sb->s_type->i_mutex_key#23){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #2: ffff88805f373220 (&sb->s_type->i_mutex_key#23){++++}-{4:4}, at: vfs_rmdir+0xf8/0x6b0 fs/namei.c:5360 stack backtrace: CPU: 0 UID: 0 PID: 8147 Comm: syz.2.733 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2059 check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2191 check_prev_add kernel/locking/lockdep.c:3181 [inline] check_prevs_add kernel/locking/lockdep.c:3300 [inline] validate_chain kernel/locking/lockdep.c:3924 [inline] __lock_acquire+0x15ff/0x2e40 kernel/locking/lockdep.c:5254 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5906 __mutex_lock_common kernel/locking/rtmutex_api.c:559 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:578 configfs_rmdir+0x5f0/0x950 fs/configfs/dir.c:1556 vfs_rmdir+0x3e9/0x6b0 fs/namei.c:5375 filename_rmdir+0x292/0x520 fs/namei.c:5432 __do_sys_rmdir fs/namei.c:5455 [inline] __se_sys_rmdir+0x2e/0x140 fs/namei.c:5452 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x17b/0x530 arch/x86/entry/syscall_64.c:85 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdfabbbe0d9 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:00007fdfa9e16028 EFLAGS: 00000246 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 00007fdfabe45fa0 RCX: 00007fdfabbbe0d9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00002000000001c0 RBP: 00007fdfabc55024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdfabe46038 R14: 00007fdfabe45fa0 R15: 00007ffcaaa8c578