====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.2.1567/18327 is trying to acquire lock: ffffffff8f9eca68 (gadget_subsys.su_mutex){+.+.}-{4:4}, at: uvcg_format_bma_controls_show drivers/usb/gadget/function/uvc_configfs.c:1681 [inline] ffffffff8f9eca68 (gadget_subsys.su_mutex){+.+.}-{4:4}, at: uvcg_mjpeg_bma_controls_show+0x4d/0x140 drivers/usb/gadget/function/uvc_configfs.c:2635 but task is already holding lock: ffff8880340a7570 (&p->frag_sem){++++}-{4:4}, at: fill_read_buffer fs/configfs/file.c:66 [inline] ffff8880340a7570 (&p->frag_sem){++++}-{4:4}, at: configfs_read_iter+0x1cc/0x620 fs/configfs/file.c:88 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&p->frag_sem){++++}-{4:4}: down_write_killable+0xa6/0x240 kernel/locking/rwsem.c:1643 configfs_rmdir+0x3b0/0x950 fs/configfs/dir.c:1534 vfs_rmdir+0x3e6/0x6a0 fs/namei.c:5515 filename_rmdir+0x292/0x520 fs/namei.c:5572 __do_sys_unlinkat fs/namei.c:5747 [inline] __se_sys_unlinkat+0x71/0x1a0 fs/namei.c:5740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&sb->s_type->i_mutex_key#29){++++}-{4:4}: down_write+0x96/0x200 kernel/locking/rwsem.c:1631 inode_lock include/linux/fs.h:1025 [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+0x40c/0x620 fs/namei.c:5410 filename_mkdirat+0x285/0x510 fs/namei.c:5443 __do_sys_mkdir fs/namei.c:5470 [inline] __se_sys_mkdir+0x34/0x150 fs/namei.c:5467 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&opts->dep_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821 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+0x40c/0x620 fs/namei.c:5410 filename_mkdirat+0x285/0x510 fs/namei.c:5443 __do_sys_mkdir fs/namei.c:5470 [inline] __se_sys_mkdir+0x34/0x150 fs/namei.c:5467 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (gadget_subsys.su_mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x1520/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821 uvcg_format_bma_controls_show drivers/usb/gadget/function/uvc_configfs.c:1681 [inline] uvcg_mjpeg_bma_controls_show+0x4d/0x140 drivers/usb/gadget/function/uvc_configfs.c:2635 fill_read_buffer fs/configfs/file.c:68 [inline] configfs_read_iter+0x2b7/0x620 fs/configfs/file.c:88 __kernel_read+0x4ca/0x960 fs/read_write.c:532 integrity_kernel_read+0x89/0xd0 security/integrity/iint.c:28 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:222 [inline] ima_calc_file_hash+0x451/0x890 security/integrity/ima/ima_crypto.c:280 ima_collect_measurement+0x51b/0xa00 security/integrity/ima/ima_api.c:300 process_measurement+0x1272/0x1c10 security/integrity/ima/ima_main.c:425 ima_file_check+0xe1/0x130 security/integrity/ima/ima_main.c:685 security_file_post_open+0xb3/0x260 security/security.c:2755 do_open fs/namei.c:4839 [inline] path_openat+0x1485/0x1d60 fs/namei.c:5000 do_file_open+0x23e/0x4a0 fs/namei.c:5029 do_sys_openat2+0x115/0x200 fs/open.c:1417 do_sys_open fs/open.c:1423 [inline] __do_sys_openat fs/open.c:1439 [inline] __se_sys_openat fs/open.c:1434 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1434 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 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: gadget_subsys.su_mutex --> &sb->s_type->i_mutex_key#29 --> &p->frag_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(&p->frag_sem); lock(&sb->s_type->i_mutex_key#29); lock(&p->frag_sem); lock(gadget_subsys.su_mutex); *** DEADLOCK *** 3 locks held by syz.2.1567/18327: #0: ffff88803139ecc0 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}, at: process_measurement+0x7d0/0x1c10 security/integrity/ima/ima_main.c:319 #1: ffff888052afda80 (&buffer->mutex){+.+.}-{4:4}, at: configfs_read_iter+0x70/0x620 fs/configfs/file.c:86 #2: ffff8880340a7570 (&p->frag_sem){++++}-{4:4}, at: fill_read_buffer fs/configfs/file.c:66 [inline] #2: ffff8880340a7570 (&p->frag_sem){++++}-{4:4}, at: configfs_read_iter+0x1cc/0x620 fs/configfs/file.c:88 stack backtrace: CPU: 0 UID: 0 PID: 18327 Comm: syz.2.1567 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x1520/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821 uvcg_format_bma_controls_show drivers/usb/gadget/function/uvc_configfs.c:1681 [inline] uvcg_mjpeg_bma_controls_show+0x4d/0x140 drivers/usb/gadget/function/uvc_configfs.c:2635 fill_read_buffer fs/configfs/file.c:68 [inline] configfs_read_iter+0x2b7/0x620 fs/configfs/file.c:88 __kernel_read+0x4ca/0x960 fs/read_write.c:532 integrity_kernel_read+0x89/0xd0 security/integrity/iint.c:28 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:222 [inline] ima_calc_file_hash+0x451/0x890 security/integrity/ima/ima_crypto.c:280 ima_collect_measurement+0x51b/0xa00 security/integrity/ima/ima_api.c:300 process_measurement+0x1272/0x1c10 security/integrity/ima/ima_main.c:425 ima_file_check+0xe1/0x130 security/integrity/ima/ima_main.c:685 security_file_post_open+0xb3/0x260 security/security.c:2755 do_open fs/namei.c:4839 [inline] path_openat+0x1485/0x1d60 fs/namei.c:5000 do_file_open+0x23e/0x4a0 fs/namei.c:5029 do_sys_openat2+0x115/0x200 fs/open.c:1417 do_sys_open fs/open.c:1423 [inline] __do_sys_openat fs/open.c:1439 [inline] __se_sys_openat fs/open.c:1434 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1434 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9156b9e0d9 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:00007f9157af6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f9156e26180 RCX: 00007f9156b9e0d9 RDX: 0000000000000002 RSI: 00002000000002c0 RDI: ffffffffffffff9c RBP: 00007f9156c35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9156e26218 R14: 00007f9156e26180 R15: 00007ffdbb4f91f8