ipv6_addr_label(addr=fe80:0000:0000:0000:0000:0000:0000:0016, type=0, ifindex=5) => 00000001 CORE_HBA[0] - TCM Ramdisk HBA Driver v4.0 on Generic Target Core Stack v5.0 CORE_HBA[1] - Attached HBA to Generic Target Core configfs: configfs rd_mcp_0: dropping attrs for dir configfs: o rd_mcp_0 removing done (2) ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.5.6232/27522 is trying to acquire lock: ffffffff90fb4c28 (&subsys->su_mutex){+.+.}-{4:4}, at: configfs_rmdir+0x5ae/0x950 fs/configfs/dir.c:1565 but task is already holding lock: ffff888094c1ec00 (&sb->s_type->i_mutex_key#33){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] ffff888094c1ec00 (&sb->s_type->i_mutex_key#33){++++}-{4:4}, at: vfs_rmdir fs/namei.c:5499 [inline] ffff888094c1ec00 (&sb->s_type->i_mutex_key#33){++++}-{4:4}, at: vfs_rmdir+0xed/0x8a0 fs/namei.c:5487 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&sb->s_type->i_mutex_key#33){++++}-{4:4}: lock_acquire kernel/locking/lockdep.c:5942 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899 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:1268 usbg_make_tpg+0x251/0x610 drivers/usb/gadget/function/f_tcm.c:1692 target_fabric_make_tpg+0xab/0x8c0 drivers/target/target_core_fabric_configfs.c:947 configfs_mkdir+0x525/0xd40 fs/configfs/dir.c:1369 vfs_mkdir+0x364/0x850 fs/namei.c:5409 filename_mkdirat+0x48b/0x5e0 fs/namei.c:5442 __do_sys_mkdirat fs/namei.c:5463 [inline] __se_sys_mkdirat fs/namei.c:5460 [inline] __x64_sys_mkdirat+0x89/0xc0 fs/namei.c:5460 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (tpg_instances_lock){+.+.}-{4:4}: lock_acquire kernel/locking/lockdep.c:5942 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821 usbg_make_tpg+0x10b/0x610 drivers/usb/gadget/function/f_tcm.c:1669 target_fabric_make_tpg+0xab/0x8c0 drivers/target/target_core_fabric_configfs.c:947 configfs_mkdir+0x525/0xd40 fs/configfs/dir.c:1369 vfs_mkdir+0x364/0x850 fs/namei.c:5409 filename_mkdirat+0x48b/0x5e0 fs/namei.c:5442 __do_sys_mkdirat fs/namei.c:5463 [inline] __se_sys_mkdirat fs/namei.c:5460 [inline] __x64_sys_mkdirat+0x89/0xc0 fs/namei.c:5460 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&subsys->su_mutex){+.+.}-{4:4}: check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3209 check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x1528/0x1f40 kernel/locking/lockdep.c:5288 lock_acquire kernel/locking/lockdep.c:5942 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899 __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:1565 vfs_rmdir fs/namei.c:5514 [inline] vfs_rmdir+0x328/0x8a0 fs/namei.c:5487 filename_rmdir+0x31a/0x5c0 fs/namei.c:5571 __do_sys_rmdir fs/namei.c:5594 [inline] __se_sys_rmdir fs/namei.c:5591 [inline] __x64_sys_rmdir+0x46/0x70 fs/namei.c:5591 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &subsys->su_mutex --> tpg_instances_lock --> &sb->s_type->i_mutex_key#33 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#33); lock(tpg_instances_lock); lock(&sb->s_type->i_mutex_key#33); lock(&subsys->su_mutex); *** DEADLOCK *** locks held by syz.5.6232/27522: 3, last CPU#0: #0: ffff88801f76a460 (sb_writers#21){.+.+}-{0:0}, at: filename_rmdir+0x1ff/0x5c0 fs/namei.c:5560 #1: ffff888029670ac0 (&default_group_class[depth - 1]#7/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline] #1: ffff888029670ac0 (&default_group_class[depth - 1]#7/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline] #1: ffff888029670ac0 (&default_group_class[depth - 1]#7/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline] #1: ffff888029670ac0 (&default_group_class[depth - 1]#7/1){+.+.}-{4:4}, at: filename_rmdir+0x258/0x5c0 fs/namei.c:5564 #2: ffff888094c1ec00 (&sb->s_type->i_mutex_key#33){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #2: ffff888094c1ec00 (&sb->s_type->i_mutex_key#33){++++}-{4:4}, at: vfs_rmdir fs/namei.c:5499 [inline] #2: ffff888094c1ec00 (&sb->s_type->i_mutex_key#33){++++}-{4:4}, at: vfs_rmdir+0xed/0x8a0 fs/namei.c:5487 stack backtrace: CPU: 0 UID: 0 PID: 27522 Comm: syz.5.6232 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_circular_bug.cold+0x178/0x1be kernel/locking/lockdep.c:2087 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2219 check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3209 check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x1528/0x1f40 kernel/locking/lockdep.c:5288 lock_acquire kernel/locking/lockdep.c:5942 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899 __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:1565 vfs_rmdir fs/namei.c:5514 [inline] vfs_rmdir+0x328/0x8a0 fs/namei.c:5487 filename_rmdir+0x31a/0x5c0 fs/namei.c:5571 __do_sys_rmdir fs/namei.c:5594 [inline] __se_sys_rmdir fs/namei.c:5591 [inline] __x64_sys_rmdir+0x46/0x70 fs/namei.c:5591 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f143439e559 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:00007f1435338028 EFLAGS: 00000246 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 00007f1434625fa0 RCX: 00007f143439e559 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000900 RBP: 00007f1434435ab8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1434626038 R14: 00007f1434625fa0 R15: 00007fff706bae18 config_item rd_mcp_0: cleaning up CORE_HBA[1] - Detached Ramdisk HBA: 0 from Generic Target Core CORE_HBA[1] - Detached HBA from Generic Target Core kcov: kcov_task_exit: t = ffff88807c93cb00, kcov->t = ffff88807c93cb00