====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.3.2104/13767 is trying to acquire lock: ffff88806b460450 (sb_writers#5){.+.+}-{0:0}, at: open_last_lookups fs/namei.c:4597 [inline] ffff88806b460450 (sb_writers#5){.+.+}-{0:0}, at: path_openat+0xad9/0x4280 fs/namei.c:4860 but task is already holding lock: ffff888013f4b068 (&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_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 -> #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 __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 -> #1 (&ima_iint_mutex_key[depth]){+.+.}-{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 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 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+0x115/0x840 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (sb_writers#5){.+.+}-{0:0}: 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 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 include/linux/fs/super.h:125 [inline] mnt_want_write+0x6f/0x410 fs/namespace.c:494 open_last_lookups fs/namei.c:4597 [inline] path_openat+0xad9/0x4280 fs/namei.c:4860 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: sb_writers#5 --> &p->frag_sem --> &subsys->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&subsys->lock); lock(&p->frag_sem); lock(&subsys->lock); rlock(sb_writers#5); *** DEADLOCK *** 6 locks held by syz.3.2104/13767: #0: ffff888024dc8ef0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259 #1: ffff888021f28450 (sb_writers#22){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739 #2: ffff88804be3b880 (&buffer->mutex#2){+.+.}-{4:4}, at: configfs_write_iter+0x76/0x4e0 fs/configfs/file.c:226 #3: ffff88806beb1170 (&p->frag_sem){.+.+}-{4:4}, at: flush_write_buffer fs/configfs/file.c:205 [inline] #3: ffff88806beb1170 (&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: ffff888013f4b068 (&subsys->lock){+.+.}-{4:4}, at: nvmet_ns_enable+0x4f/0x5d0 drivers/nvme/target/core.c:583 stack backtrace: CPU: 1 UID: 0 PID: 13767 Comm: syz.3.2104 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_circular_bug.cold+0x178/0x1c7 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 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 include/linux/fs/super.h:125 [inline] mnt_want_write+0x6f/0x410 fs/namespace.c:494 open_last_lookups fs/namei.c:4597 [inline] path_openat+0xad9/0x4280 fs/namei.c:4860 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: 0023:0xf6feefec Code: Unable to access opcode bytes at 0xf6feefc2. RSP: 002b:00000000f53dd50c EFLAGS: 00000292 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000080000200 RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 nvmet: failed to open file ./file0: (-2)