nvmet: adding nsid 1 to subsystem subsys1
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.409/7436 is trying to acquire lock:
ffff8880701a5818 (&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:
ffff88801d39d868 (&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:

-> #2 (&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_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
       __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307
       do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #1 (&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
       __configfs_open_file+0xe8/0x9c0 fs/configfs/file.c:304
       do_dentry_open+0x6ab/0x14d0 fs/open.c:947
       vfs_open+0x82/0x3f0 fs/open.c:1052
       dentry_open+0x71/0xd0 fs/open.c:1075
       ima_calc_file_hash+0xe1/0x380 security/integrity/ima/ima_crypto.c:269
       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+0xcc/0x120 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_compat_sys_openat fs/open.c:1436 [inline]
       __se_compat_sys_openat fs/open.c:1434 [inline]
       __ia32_compat_sys_openat+0x12d/0x210 fs/open.c:1434
       do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
       __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307
       do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #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+0xcc/0x120 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_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
       __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307
       do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

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.0.409/7436:
 #0: ffff8880247f07f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
 #1: ffff888021f68450 (sb_writers#12){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739
 #2: ffff888023467480 (&buffer->mutex){+.+.}-{4:4}, at: configfs_write_iter+0x76/0x4e0 fs/configfs/file.c:226
 #3: ffff88805fa7ed70 (&p->frag_sem){++++}-{4:4}, at: flush_write_buffer fs/configfs/file.c:205 [inline]
 #3: ffff88805fa7ed70 (&p->frag_sem){++++}-{4:4}, at: configfs_write_iter+0x218/0x4e0 fs/configfs/file.c:229
 #4: ffffffff8fd33748 (nvmet_config_sem){+.+.}-{4:4}, at: nvmet_ns_enable_store+0xa5/0x160 drivers/nvme/target/configfs.c:733
 #5: ffff88801d39d868 (&subsys->lock){+.+.}-{4:4}, at: nvmet_ns_enable+0x4f/0x5d0 drivers/nvme/target/core.c:583

stack backtrace:
CPU: 2 UID: 0 PID: 7436 Comm: syz.0.409 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
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+0xcc/0x120 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_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf70befec
Code: Unable to access opcode bytes at 0xf70befc2.
RSP: 002b:00000000f54ad50c EFLAGS: 00000292 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 0000000080000200
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 2 UID: 0 PID: 7436 Comm: syz.0.409 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 fail_dump lib/fault-inject.c:73 [inline]
 should_fail_ex.cold+0x5/0xa lib/fault-inject.c:174
 should_failslab+0xc2/0x120 mm/failslab.c:46
 slab_pre_alloc_hook mm/slub.c:4539 [inline]
 slab_alloc_node mm/slub.c:4897 [inline]
 kmem_cache_alloc_noprof+0x91/0x6a0 mm/slub.c:4931
 mempool_init_node+0x2f7/0x6e0 mm/mempool.c:259
 mempool_create_node_noprof+0xe9/0x1b0 mm/mempool.c:323
 nvmet_file_ns_enable+0x255/0x420 drivers/nvme/target/io-cmd-file.c:59
 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_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf70befec
Code: Unable to access opcode bytes at 0xf70befc2.
RSP: 002b:00000000f54ad50c EFLAGS: 00000292 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 0000000080000200
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>