nvmet: adding nsid 1 to subsystem testnqn
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G             L     
------------------------------------------------------
syz.6.5281/25699 is trying to acquire lock:
ffff888060f32ed0 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}, at: process_measurement+0x5ab/0x2350 security/integrity/ima/ima_main.c:319

but task is already holding lock:
ffff88807e111068 (&subsys->lock){+.+.}-{4:4}, at: nvmet_ns_enable+0x4f/0x5d0 drivers/nvme/target/core.c:583

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&subsys->lock){+.+.}-{4:4}:
       lock_acquire kernel/locking/lockdep.c:5868 [inline]
       lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821
       nvmet_ns_device_path_store+0x57/0x1c0 drivers/nvme/target/configfs.c:536
       flush_write_buffer fs/configfs/file.c:207 [inline]
       configfs_write_iter+0x302/0x4e0 fs/configfs/file.c:229
       new_sync_write fs/read_write.c:595 [inline]
       vfs_write+0x6ac/0x1050 fs/read_write.c:687
       ksys_write+0x12a/0x250 fs/read_write.c:739
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (&p->frag_sem){.+.+}-{4:4}:
       lock_acquire kernel/locking/lockdep.c:5868 [inline]
       lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
       down_read+0x99/0x4c0 kernel/locking/rwsem.c:1574
       fill_read_buffer fs/configfs/file.c:66 [inline]
       configfs_read_iter+0x346/0x6f0 fs/configfs/file.c:88
       __kernel_read+0x397/0xad0 fs/read_write.c:532
       integrity_kernel_read+0x7e/0xb0 security/integrity/iint.c:28
       ima_calc_file_hash_tfm+0x25e/0x350 security/integrity/ima/ima_crypto.c:222
       ima_calc_file_hash+0x1e3/0x380 security/integrity/ima/ima_crypto.c:280
       ima_collect_measurement+0x94f/0xb30 security/integrity/ima/ima_api.c:300
       process_measurement+0xdfe/0x2350 security/integrity/ima/ima_main.c:425
       ima_file_check+0xc3/0x110 security/integrity/ima/ima_main.c:685
       security_file_post_open+0xc4/0x210 security/security.c:2755
       do_open fs/namei.c:4702 [inline]
       path_openat+0x985/0x4280 fs/namei.c:4863
       do_file_open+0x20e/0x430 fs/namei.c:4892
       do_sys_openat2+0x10f/0x1e0 fs/open.c:1368
       do_sys_open fs/open.c:1374 [inline]
       __do_sys_openat fs/open.c:1390 [inline]
       __se_sys_openat fs/open.c:1385 [inline]
       __x64_sys_openat+0x12d/0x210 fs/open.c:1385
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&buffer->mutex){+.+.}-{4:4}:
       lock_acquire kernel/locking/lockdep.c:5868 [inline]
       lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821
       configfs_read_iter+0x79/0x6f0 fs/configfs/file.c:86
       __kernel_read+0x397/0xad0 fs/read_write.c:532
       integrity_kernel_read+0x7e/0xb0 security/integrity/iint.c:28
       ima_calc_file_hash_tfm+0x25e/0x350 security/integrity/ima/ima_crypto.c:222
       ima_calc_file_hash+0x1e3/0x380 security/integrity/ima/ima_crypto.c:280
       ima_collect_measurement+0x94f/0xb30 security/integrity/ima/ima_api.c:300
       process_measurement+0xdfe/0x2350 security/integrity/ima/ima_main.c:425
       ima_file_check+0xc3/0x110 security/integrity/ima/ima_main.c:685
       security_file_post_open+0xc4/0x210 security/security.c:2755
       do_open fs/namei.c:4702 [inline]
       path_openat+0x985/0x4280 fs/namei.c:4863
       do_file_open+0x20e/0x430 fs/namei.c:4892
       do_sys_openat2+0x10f/0x1e0 fs/open.c:1368
       do_sys_open fs/open.c:1374 [inline]
       __do_sys_openat fs/open.c:1390 [inline]
       __se_sys_openat fs/open.c:1385 [inline]
       __x64_sys_openat+0x12d/0x210 fs/open.c:1385
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}:
       check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3165
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x136c/0x1a40 kernel/locking/lockdep.c:5237
       lock_acquire kernel/locking/lockdep.c:5868 [inline]
       lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821
       process_measurement+0x5ab/0x2350 security/integrity/ima/ima_main.c:319
       ima_file_check+0xc3/0x110 security/integrity/ima/ima_main.c:685
       security_file_post_open+0xc4/0x210 security/security.c:2755
       do_open fs/namei.c:4702 [inline]
       path_openat+0x985/0x4280 fs/namei.c:4863
       do_file_open+0x20e/0x430 fs/namei.c:4892
       file_open_name+0x1c3/0x3e0 fs/open.c:1326
       filp_open+0x2e/0x50 fs/open.c:1343
       nvmet_file_ns_enable+0x95/0x420 drivers/nvme/target/io-cmd-file.c:41
       nvmet_ns_enable+0x35f/0x5d0 drivers/nvme/target/core.c:596
       nvmet_ns_enable_store+0x11e/0x160 drivers/nvme/target/configfs.c:735
       flush_write_buffer fs/configfs/file.c:207 [inline]
       configfs_write_iter+0x302/0x4e0 fs/configfs/file.c:229
       new_sync_write fs/read_write.c:595 [inline]
       vfs_write+0x6ac/0x1050 fs/read_write.c:687
       ksys_write+0x12a/0x250 fs/read_write.c:739
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x115/0x870 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:
  &ima_iint_mutex_key[depth] --> &p->frag_sem --> &subsys->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&subsys->lock);
                               lock(&p->frag_sem);
                               lock(&subsys->lock);
  lock(&ima_iint_mutex_key[depth]);

 *** DEADLOCK ***

6 locks held by syz.6.5281/25699:
 #0: ffff88807dc290b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
 #1: ffff88801df98450 (sb_writers#15){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739
 #2: ffff88807a313280 (&buffer->mutex){+.+.}-{4:4}, at: configfs_write_iter+0x76/0x4e0 fs/configfs/file.c:226
 #3: ffff88802cce2470 (&p->frag_sem){.+.+}-{4:4}, at: flush_write_buffer fs/configfs/file.c:205 [inline]
 #3: ffff88802cce2470 (&p->frag_sem){.+.+}-{4:4}, at: configfs_write_iter+0x218/0x4e0 fs/configfs/file.c:229
 #4: ffffffff8fd27d08 (nvmet_config_sem){+.+.}-{4:4}, at: nvmet_ns_enable_store+0xa5/0x160 drivers/nvme/target/configfs.c:733
 #5: ffff88807e111068 (&subsys->lock){+.+.}-{4:4}, at: nvmet_ns_enable+0x4f/0x5d0 drivers/nvme/target/core.c:583

stack backtrace:
CPU: 1 UID: 0 PID: 25699 Comm: syz.6.5281 Tainted: G             L      syzkaller #0 PREEMPT(lazy) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_circular_bug.cold+0x178/0x1c7 kernel/locking/lockdep.c:2043
 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2175
 check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3165
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x136c/0x1a40 kernel/locking/lockdep.c:5237
 lock_acquire kernel/locking/lockdep.c:5868 [inline]
 lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
 __mutex_lock_common kernel/locking/mutex.c:646 [inline]
 __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821
 process_measurement+0x5ab/0x2350 security/integrity/ima/ima_main.c:319
 ima_file_check+0xc3/0x110 security/integrity/ima/ima_main.c:685
 security_file_post_open+0xc4/0x210 security/security.c:2755
 do_open fs/namei.c:4702 [inline]
 path_openat+0x985/0x4280 fs/namei.c:4863
 do_file_open+0x20e/0x430 fs/namei.c:4892
 file_open_name+0x1c3/0x3e0 fs/open.c:1326
 filp_open+0x2e/0x50 fs/open.c:1343
 nvmet_file_ns_enable+0x95/0x420 drivers/nvme/target/io-cmd-file.c:41
 nvmet_ns_enable+0x35f/0x5d0 drivers/nvme/target/core.c:596
 nvmet_ns_enable_store+0x11e/0x160 drivers/nvme/target/configfs.c:735
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x302/0x4e0 fs/configfs/file.c:229
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6ac/0x1050 fs/read_write.c:687
 ksys_write+0x12a/0x250 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb5dc19e0d9
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:00007fb5dcfdf028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fb5dc425fa0 RCX: 00007fb5dc19e0d9
RDX: 0000000000000001 RSI: 0000200000000580 RDI: 0000000000000008
RBP: 00007fb5dc235024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb5dc426038 R14: 00007fb5dc425fa0 R15: 00007ffdec8f6028
 </TASK>
nvme nvme0: creating 2 I/O queues.
nvme nvme0: new ctrl: "testnqn"