====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.3756/21398 is trying to acquire lock: ffff888020cc1fc0 (&sb->s_type->i_mutex_key#24){++++}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] ffff888020cc1fc0 (&sb->s_type->i_mutex_key#24){++++}-{3:3}, at: configfs_depend_item_unlocked+0x157/0x460 fs/configfs/dir.c:1251 but task is already holding lock: ffffffff8ec57308 (tpg_instances_lock){+.+.}-{3:3}, at: usbg_make_tpg+0xf9/0x550 drivers/usb/gadget/function/f_tcm.c:1324 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (tpg_instances_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x135/0xc80 kernel/locking/mutex.c:747 usbg_make_tpg+0xf9/0x550 drivers/usb/gadget/function/f_tcm.c:1324 target_fabric_make_tpg+0xa4/0x6d0 drivers/target/target_core_fabric_configfs.c:947 configfs_mkdir+0x515/0x9e0 fs/configfs/dir.c:1356 vfs_mkdir+0x2a5/0x470 fs/namei.c:4168 do_mkdirat+0x1dc/0x450 fs/namei.c:4191 __do_sys_mkdirat fs/namei.c:4206 [inline] __se_sys_mkdirat fs/namei.c:4204 [inline] __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4204 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #1 (&subsys->su_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x135/0xc80 kernel/locking/mutex.c:747 configfs_rmdir+0x63c/0x980 fs/configfs/dir.c:1552 vfs_rmdir+0x352/0x4b0 fs/namei.c:4251 do_rmdir+0x29f/0x590 fs/namei.c:4310 __do_sys_rmdir fs/namei.c:4329 [inline] __se_sys_rmdir fs/namei.c:4327 [inline] __x64_sys_rmdir+0x49/0x50 fs/namei.c:4327 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&sb->s_type->i_mutex_key#24){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3162 [inline] check_prevs_add kernel/locking/lockdep.c:3281 [inline] validate_chain kernel/locking/lockdep.c:3897 [inline] __lock_acquire+0x3a07/0x7eb0 kernel/locking/lockdep.c:5171 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5790 down_write+0x97/0x200 kernel/locking/rwsem.c:1573 inode_lock include/linux/fs.h:804 [inline] configfs_depend_item_unlocked+0x157/0x460 fs/configfs/dir.c:1251 usbg_make_tpg+0x1e1/0x550 drivers/usb/gadget/function/f_tcm.c:1347 target_fabric_make_tpg+0xa4/0x6d0 drivers/target/target_core_fabric_configfs.c:947 configfs_mkdir+0x515/0x9e0 fs/configfs/dir.c:1356 vfs_mkdir+0x2a5/0x470 fs/namei.c:4168 do_mkdirat+0x1dc/0x450 fs/namei.c:4191 __do_sys_mkdirat fs/namei.c:4206 [inline] __se_sys_mkdirat fs/namei.c:4204 [inline] __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4204 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Chain exists of: &sb->s_type->i_mutex_key#24 --> &subsys->su_mutex --> tpg_instances_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(tpg_instances_lock); lock(&subsys->su_mutex); lock(tpg_instances_lock); lock(&sb->s_type->i_mutex_key#24); *** DEADLOCK *** 4 locks held by syz.0.3756/21398: #0: ffff888019350418 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412 #1: ffff88805d9cf910 (&sb->s_type->i_mutex_key#7/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline] #1: ffff88805d9cf910 (&sb->s_type->i_mutex_key#7/1){+.+.}-{3:3}, at: filename_create+0x20f/0x450 fs/namei.c:3937 #2: ffffffff8e92c330 (&subsys->su_mutex){+.+.}-{3:3}, at: configfs_mkdir+0x4b9/0x9e0 fs/configfs/dir.c:1354 #3: ffffffff8ec57308 (tpg_instances_lock){+.+.}-{3:3}, at: usbg_make_tpg+0xf9/0x550 drivers/usb/gadget/function/f_tcm.c:1324 stack backtrace: CPU: 1 PID: 21398 Comm: syz.0.3756 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2215 check_prev_add kernel/locking/lockdep.c:3162 [inline] check_prevs_add kernel/locking/lockdep.c:3281 [inline] validate_chain kernel/locking/lockdep.c:3897 [inline] __lock_acquire+0x3a07/0x7eb0 kernel/locking/lockdep.c:5171 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5790 down_write+0x97/0x200 kernel/locking/rwsem.c:1573 inode_lock include/linux/fs.h:804 [inline] configfs_depend_item_unlocked+0x157/0x460 fs/configfs/dir.c:1251 usbg_make_tpg+0x1e1/0x550 drivers/usb/gadget/function/f_tcm.c:1347 target_fabric_make_tpg+0xa4/0x6d0 drivers/target/target_core_fabric_configfs.c:947 configfs_mkdir+0x515/0x9e0 fs/configfs/dir.c:1356 vfs_mkdir+0x2a5/0x470 fs/namei.c:4168 do_mkdirat+0x1dc/0x450 fs/namei.c:4191 __do_sys_mkdirat fs/namei.c:4206 [inline] __se_sys_mkdirat fs/namei.c:4204 [inline] __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4204 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc3be59e1d9 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:00007fc3bf4f0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fc3be825fa0 RCX: 00007fc3be59e1d9 RDX: 00000000000001ff RSI: 0000200000000540 RDI: ffffffffffffff9c RBP: 00007fc3be635888 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc3be826038 R14: 00007fc3be825fa0 R15: 00007ffdef570b38 TARGET_CORE[usb_gadget]: Allocated portal_group for endpoint: 5001405000000001, Proto: 6, Portal Tag: 1 kcov: kcov_task_exit: t = ffff8880286b9e00, kcov->t = ffff8880286b9e00