LUN: removable file: (no medium)
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G             L     
------------------------------------------------------
syz.3.4206/20547 is trying to acquire lock:
ffff88807ae88460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494

but task is already holding lock:
ffff88807edc7120 (&common->filesem){++++}-{4:4}, at: fsg_store_file+0x163/0x400 drivers/usb/gadget/function/storage_common.c:452

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&common->filesem){++++}-{4:4}:
       down_read+0x4a/0x330 kernel/locking/rwsem.c:1574
       fsg_show_file+0x2d/0x140 drivers/usb/gadget/function/storage_common.c:339
       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:4915 [inline]
       path_openat+0x151f/0x1e50 fs/namei.c:5078
       do_file_open+0x23e/0x4a0 fs/namei.c:5107
       do_sys_openat2+0x115/0x200 fs/open.c:1452
       do_sys_open fs/open.c:1458 [inline]
       __do_sys_openat fs/open.c:1474 [inline]
       __se_sys_openat fs/open.c:1469 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1469
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (&p->frag_sem){.+.+}-{4:4}:
       down_read+0x4a/0x330 kernel/locking/rwsem.c:1574
       __configfs_open_file+0xd8/0x7d0 fs/configfs/file.c:304
       do_dentry_open+0x80e/0x1360 fs/open.c:1000
       vfs_open+0x43/0x350 fs/open.c:1107
       dentry_open+0x61/0xa0 fs/open.c:1149
       ima_calc_file_hash+0x15f/0x890 security/integrity/ima/ima_crypto.c:269
       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:4915 [inline]
       path_openat+0x151f/0x1e50 fs/namei.c:5078
       do_file_open+0x23e/0x4a0 fs/namei.c:5107
       do_sys_openat2+0x115/0x200 fs/open.c:1452
       do_sys_open fs/open.c:1458 [inline]
       __do_sys_openat fs/open.c:1474 [inline]
       __se_sys_openat fs/open.c:1469 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1469
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x19c/0x15a0 kernel/locking/mutex.c:821
       process_measurement+0x7d0/0x1c10 security/integrity/ima/ima_main.c:319
       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:4915 [inline]
       path_openat+0x151f/0x1e50 fs/namei.c:5078
       do_file_open+0x23e/0x4a0 fs/namei.c:5107
       do_sys_openat2+0x115/0x200 fs/open.c:1452
       do_sys_open fs/open.c:1458 [inline]
       __do_sys_openat fs/open.c:1474 [inline]
       __se_sys_openat fs/open.c:1469 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1469
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (sb_writers#5){.+.+}-{0:0}:
       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/0x2e50 kernel/locking/lockdep.c:5254
       lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908
       percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
       percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
       __sb_start_write include/linux/fs/super.h:19 [inline]
       sb_start_write+0x4d/0x1d0 include/linux/fs/super.h:125
       mnt_want_write+0x41/0x90 fs/namespace.c:494
       lookup_open+0x18b/0x1380 fs/namei.c:4518
       open_last_lookups fs/namei.c:4835 [inline]
       path_openat+0x69b/0x1e50 fs/namei.c:5075
       do_file_open+0x23e/0x4a0 fs/namei.c:5107
       file_open_name fs/open.c:1410 [inline]
       filp_open+0x16d/0x1d0 fs/open.c:1427
       fsg_lun_open+0x6c/0xdf0 drivers/usb/gadget/function/storage_common.c:194
       fsg_store_file+0x19e/0x400 drivers/usb/gadget/function/storage_common.c:455
       flush_write_buffer fs/configfs/file.c:207 [inline]
       configfs_write_iter+0x337/0x430 fs/configfs/file.c:229
       new_sync_write fs/read_write.c:595 [inline]
       vfs_write+0x612/0xba0 fs/read_write.c:687
       ksys_write+0x150/0x270 fs/read_write.c:739
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x166/0x520 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:
  sb_writers#5 --> &p->frag_sem --> &common->filesem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&common->filesem);
                               lock(&p->frag_sem);
                               lock(&common->filesem);
  rlock(sb_writers#5);

 *** DEADLOCK ***

locks held by syz.3.4206/20547: 5, last CPU#0:
 #0: ffff8880741170b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
 #1: ffff88801c70a460 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
 #1: ffff88801c70a460 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
 #2: ffff88805dc99680 (&buffer->mutex){+.+.}-{4:4}, at: configfs_write_iter+0x7e/0x430 fs/configfs/file.c:226
 #3: ffff88805f6a8270 (&p->frag_sem){.+.+}-{4:4}, at: flush_write_buffer fs/configfs/file.c:205 [inline]
 #3: ffff88805f6a8270 (&p->frag_sem){.+.+}-{4:4}, at: configfs_write_iter+0x238/0x430 fs/configfs/file.c:229
 #4: ffff88807edc7120 (&common->filesem){++++}-{4:4}, at: fsg_store_file+0x163/0x400 drivers/usb/gadget/function/storage_common.c:452

stack backtrace:
CPU: 0 UID: 0 PID: 20547 Comm: syz.3.4206 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 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/0x2e50 kernel/locking/lockdep.c:5254
 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908
 percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
 percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
 __sb_start_write include/linux/fs/super.h:19 [inline]
 sb_start_write+0x4d/0x1d0 include/linux/fs/super.h:125
 mnt_want_write+0x41/0x90 fs/namespace.c:494
 lookup_open+0x18b/0x1380 fs/namei.c:4518
 open_last_lookups fs/namei.c:4835 [inline]
 path_openat+0x69b/0x1e50 fs/namei.c:5075
 do_file_open+0x23e/0x4a0 fs/namei.c:5107
 file_open_name fs/open.c:1410 [inline]
 filp_open+0x16d/0x1d0 fs/open.c:1427
 fsg_lun_open+0x6c/0xdf0 drivers/usb/gadget/function/storage_common.c:194
 fsg_store_file+0x19e/0x400 drivers/usb/gadget/function/storage_common.c:455
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x337/0x430 fs/configfs/file.c:229
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x612/0xba0 fs/read_write.c:687
 ksys_write+0x150/0x270 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0f87f9e159
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:00007f0f88e1f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f0f88225fa0 RCX: 00007f0f87f9e159
RDX: 0000000000000012 RSI: 0000200000000000 RDI: 0000000000000003
RBP: 00007f0f88035024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0f88226038 R14: 00007f0f88225fa0 R15: 00007fff32885a58
 </TASK>
mass_storage.0/lun.0: unable to open backing file: 0x0000000000010001