db_root: cannot be changed: target drivers registered ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.4.187/5024 is trying to acquire lock: ffff88801d3ea4c0 (&sb->s_type->i_mutex_key#25){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] ffff88801d3ea4c0 (&sb->s_type->i_mutex_key#25){++++}-{3:3}, at: configfs_depend_item_unlocked+0x14f/0x430 fs/configfs/dir.c:1255 but task is already holding lock: ffff888078fa8120 (&opts->dep_lock){+.+.}-{3:3}, at: usbg_make_tpg+0x144/0x580 drivers/usb/gadget/function/f_tcm.c:1343 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&opts->dep_lock){+.+.}-{3:3}: __mutex_lock_common+0x1e5/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 tcm_set_name+0x26/0x90 drivers/usb/gadget/function/f_tcm.c:2224 function_make+0x195/0x350 drivers/usb/gadget/configfs.c:620 configfs_mkdir+0x511/0x9e0 fs/configfs/dir.c:1360 vfs_mkdir+0x386/0x570 fs/namei.c:4073 do_mkdirat+0x1dd/0x5c0 fs/namei.c:4098 __do_sys_mkdir fs/namei.c:4118 [inline] __se_sys_mkdir fs/namei.c:4116 [inline] __x64_sys_mkdir+0x6a/0x80 fs/namei.c:4116 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #1 (gadget_subsys.su_mutex){+.+.}-{3:3}: __mutex_lock_common+0x1e5/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 configfs_rmdir+0x638/0x980 fs/configfs/dir.c:1556 vfs_rmdir+0x19d/0x410 fs/namei.c:4157 do_rmdir+0x27f/0x710 fs/namei.c:4218 __do_sys_rmdir fs/namei.c:4237 [inline] __se_sys_rmdir fs/namei.c:4235 [inline] __x64_sys_rmdir+0x45/0x50 fs/namei.c:4235 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&sb->s_type->i_mutex_key#25){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c66/0x7b50 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 down_write+0x38/0x60 kernel/locking/rwsem.c:1551 inode_lock include/linux/fs.h:787 [inline] configfs_depend_item_unlocked+0x14f/0x430 fs/configfs/dir.c:1255 usbg_make_tpg+0x1f3/0x580 drivers/usb/gadget/function/f_tcm.c:1351 target_fabric_make_tpg+0xa0/0x6d0 drivers/target/target_core_fabric_configfs.c:837 configfs_mkdir+0x511/0x9e0 fs/configfs/dir.c:1360 vfs_mkdir+0x386/0x570 fs/namei.c:4073 do_mkdirat+0x1dd/0x5c0 fs/namei.c:4098 __do_sys_mkdir fs/namei.c:4118 [inline] __se_sys_mkdir fs/namei.c:4116 [inline] __x64_sys_mkdir+0x6a/0x80 fs/namei.c:4116 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 other info that might help us debug this: Chain exists of: &sb->s_type->i_mutex_key#25 --> gadget_subsys.su_mutex --> &opts->dep_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&opts->dep_lock); lock(gadget_subsys.su_mutex); lock(&opts->dep_lock); lock(&sb->s_type->i_mutex_key#25); *** DEADLOCK *** 5 locks held by syz.4.187/5024: #0: ffff88801da80460 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386 #1: ffff88805d009fb0 (&sb->s_type->i_mutex_key#7/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline] #1: ffff88805d009fb0 (&sb->s_type->i_mutex_key#7/1){+.+.}-{3:3}, at: filename_create+0x20b/0x450 fs/namei.c:3843 #2: ffffffff8cc23e70 (&subsys->su_mutex){+.+.}-{3:3}, at: configfs_mkdir+0x4b5/0x9e0 fs/configfs/dir.c:1358 #3: ffffffff8cf21328 (tpg_instances_lock){+.+.}-{3:3}, at: usbg_make_tpg+0xf4/0x580 drivers/usb/gadget/function/f_tcm.c:1334 #4: ffff888078fa8120 (&opts->dep_lock){+.+.}-{3:3}, at: usbg_make_tpg+0x144/0x580 drivers/usb/gadget/function/f_tcm.c:1343 stack backtrace: CPU: 1 PID: 5024 Comm: syz.4.187 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c66/0x7b50 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 down_write+0x38/0x60 kernel/locking/rwsem.c:1551 inode_lock include/linux/fs.h:787 [inline] configfs_depend_item_unlocked+0x14f/0x430 fs/configfs/dir.c:1255 usbg_make_tpg+0x1f3/0x580 drivers/usb/gadget/function/f_tcm.c:1351 target_fabric_make_tpg+0xa0/0x6d0 drivers/target/target_core_fabric_configfs.c:837 configfs_mkdir+0x511/0x9e0 fs/configfs/dir.c:1360 vfs_mkdir+0x386/0x570 fs/namei.c:4073 do_mkdirat+0x1dd/0x5c0 fs/namei.c:4098 __do_sys_mkdir fs/namei.c:4118 [inline] __se_sys_mkdir fs/namei.c:4116 [inline] __x64_sys_mkdir+0x6a/0x80 fs/namei.c:4116 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f97b4a8ee99 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:00007f97b2ce7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007f97b4d16fa0 RCX: 00007f97b4a8ee99 RDX: 0000000000000000 RSI: 00000000000001ff RDI: 0000200000000c00 RBP: 00007f97b4b24eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f97b4d17038 R14: 00007f97b4d16fa0 R15: 00007ffc55f5f878 se_device not configured yet, cannot port link