====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.1.2932/20562 is trying to acquire lock: ffff88801caf0220 (&root->kernfs_iattr_rwsem){++++}-{4:4}, at: kernfs_unlink_sibling+0xa3/0x320 fs/kernfs/dir.c:424 but task is already holding lock: ffff88801caf0188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_drain+0x29c/0x570 fs/kernfs/dir.c:527 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #10 (&root->kernfs_rwsem){++++}-{4:4}: down_write+0x92/0x200 kernel/locking/rwsem.c:1590 kernfs_add_one+0x38/0x840 fs/kernfs/dir.c:791 kernfs_create_dir_ns+0xfc/0x1a0 fs/kernfs/dir.c:1093 internal_create_group+0x34d/0xf30 fs/sysfs/group.c:170 cpuhp_invoke_callback+0x3d5/0xa10 kernel/cpu.c:195 cpuhp_issue_call+0x1c0/0x980 kernel/cpu.c:2365 __cpuhp_setup_state_cpuslocked+0x3a1/0x7b0 kernel/cpu.c:2511 __cpuhp_setup_state+0xf4/0x300 kernel/cpu.c:2540 do_one_initcall+0x120/0x6e0 init/main.c:1269 do_initcall_level init/main.c:1331 [inline] do_initcalls init/main.c:1347 [inline] do_basic_setup init/main.c:1366 [inline] kernel_init_freeable+0x5c2/0x910 init/main.c:1579 kernel_init+0x1c/0x2b0 init/main.c:1469 ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #9 (cpuhp_state_mutex){+.+.}-{4:4}: -> #8 (cpu_hotplug_lock){++++}-{0:0}: percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read include/linux/percpu-rwsem.h:77 [inline] cpus_read_lock+0x42/0x160 kernel/cpu.c:491 static_key_slow_inc+0x12/0x30 kernel/jump_label.c:190 udp_tunnel_encap_enable include/net/udp_tunnel.h:201 [inline] setup_udp_tunnel_sock+0x53d/0x680 net/ipv4/udp_tunnel_core.c:91 l2tp_tunnel_register+0x9c8/0xbe0 net/l2tp/l2tp_core.c:1679 pppol2tp_tunnel_get.constprop.0+0x3f0/0x540 net/l2tp/l2tp_ppp.c:662 pppol2tp_connect+0xb1b/0x1ce0 net/l2tp/l2tp_ppp.c:710 __sys_connect_file+0x13e/0x1a0 net/socket.c:2086 __sys_connect+0x13b/0x160 net/socket.c:2105 __do_sys_connect net/socket.c:2111 [inline] __se_sys_connect net/socket.c:2108 [inline] __x64_sys_connect+0x72/0xb0 net/socket.c:2108 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #7 (sk_lock-AF_INET6){+.+.}-{0:0}: lock_sock_nested+0x41/0xf0 net/core/sock.c:3711 lock_sock include/net/sock.h:1669 [inline] inet_autobind+0x1a/0x1a0 net/ipv4/af_inet.c:178 inet_send_prepare+0x31b/0x530 net/ipv4/af_inet.c:837 inet_sendmsg+0x43/0x140 net/ipv4/af_inet.c:848 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg net/socket.c:729 [inline] sock_sendmsg+0x37f/0x470 net/socket.c:752 __sock_xmit+0x1e7/0x4f0 drivers/block/nbd.c:574 sock_xmit drivers/block/nbd.c:602 [inline] nbd_send_cmd+0x8e4/0x1c90 drivers/block/nbd.c:712 nbd_handle_cmd drivers/block/nbd.c:1174 [inline] nbd_queue_rq+0x940/0x12d0 drivers/block/nbd.c:1204 blk_mq_dispatch_rq_list+0x416/0x1e20 block/blk-mq.c:2120 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline] __blk_mq_sched_dispatch_requests+0xcb7/0x15f0 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd8/0x1b0 block/blk-mq-sched.c:329 blk_mq_run_hw_queue+0x239/0x670 block/blk-mq.c:2358 blk_mq_dispatch_list+0x514/0x1310 block/blk-mq.c:2919 blk_mq_flush_plug_list block/blk-mq.c:2967 [inline] blk_mq_flush_plug_list+0x130/0x600 block/blk-mq.c:2939 __blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1220 blk_finish_plug block/blk-core.c:1247 [inline] blk_finish_plug block/blk-core.c:1244 [inline] __submit_bio+0x545/0x690 block/blk-core.c:649 __submit_bio_noacct_mq block/blk-core.c:722 [inline] submit_bio_noacct_nocheck+0x660/0xd30 block/blk-core.c:751 submit_bio_noacct+0xc20/0x1ed0 block/blk-core.c:874 submit_bh fs/buffer.c:2829 [inline] block_read_full_folio+0x4db/0x850 fs/buffer.c:2461 filemap_read_folio+0xc5/0x2a0 mm/filemap.c:2413 do_read_cache_folio+0x263/0x5c0 mm/filemap.c:3957 read_mapping_folio include/linux/pagemap.h:991 [inline] read_part_sector+0xd4/0x370 block/partitions/core.c:722 adfspart_check_ICS+0x93/0x940 block/partitions/acorn.c:360 check_partition block/partitions/core.c:141 [inline] blk_add_partitions block/partitions/core.c:589 [inline] bdev_disk_changed+0x720/0x1520 block/partitions/core.c:693 blkdev_get_whole+0x187/0x290 block/bdev.c:748 bdev_open+0x2c7/0xe40 block/bdev.c:957 blkdev_open+0x34e/0x4f0 block/fops.c:694 do_dentry_open+0x97f/0x1530 fs/open.c:965 vfs_open+0x82/0x3f0 fs/open.c:1095 do_open fs/namei.c:3887 [inline] path_openat+0x1de4/0x2cb0 fs/namei.c:4046 do_filp_open+0x20b/0x470 fs/namei.c:4073 do_sys_openat2+0x11b/0x1d0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #6 (&nsock->tx_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x193/0x1060 kernel/locking/mutex.c:760 nbd_handle_cmd drivers/block/nbd.c:1140 [inline] nbd_queue_rq+0x423/0x12d0 drivers/block/nbd.c:1204 blk_mq_dispatch_rq_list+0x416/0x1e20 block/blk-mq.c:2120 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline] __blk_mq_sched_dispatch_requests+0xcb7/0x15f0 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd8/0x1b0 block/blk-mq-sched.c:329 blk_mq_run_hw_queue+0x239/0x670 block/blk-mq.c:2358 blk_mq_dispatch_list+0x514/0x1310 block/blk-mq.c:2919 blk_mq_flush_plug_list block/blk-mq.c:2967 [inline] blk_mq_flush_plug_list+0x130/0x600 block/blk-mq.c:2939 __blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1220 blk_finish_plug block/blk-core.c:1247 [inline] blk_finish_plug block/blk-core.c:1244 [inline] __submit_bio+0x545/0x690 block/blk-core.c:649 __submit_bio_noacct_mq block/blk-core.c:722 [inline] submit_bio_noacct_nocheck+0x660/0xd30 block/blk-core.c:751 submit_bio_noacct+0xc20/0x1ed0 block/blk-core.c:874 submit_bh fs/buffer.c:2829 [inline] block_read_full_folio+0x4db/0x850 fs/buffer.c:2461 filemap_read_folio+0xc5/0x2a0 mm/filemap.c:2413 do_read_cache_folio+0x263/0x5c0 mm/filemap.c:3957 read_mapping_folio include/linux/pagemap.h:991 [inline] read_part_sector+0xd4/0x370 block/partitions/core.c:722 adfspart_check_ICS+0x93/0x940 block/partitions/acorn.c:360 check_partition block/partitions/core.c:141 [inline] blk_add_partitions block/partitions/core.c:589 [inline] bdev_disk_changed+0x720/0x1520 block/partitions/core.c:693 blkdev_get_whole+0x187/0x290 block/bdev.c:748 bdev_open+0x2c7/0xe40 block/bdev.c:957 blkdev_open+0x34e/0x4f0 block/fops.c:694 do_dentry_open+0x97f/0x1530 fs/open.c:965 vfs_open+0x82/0x3f0 fs/open.c:1095 do_open fs/namei.c:3887 [inline] path_openat+0x1de4/0x2cb0 fs/namei.c:4046 do_filp_open+0x20b/0x470 fs/namei.c:4073 do_sys_openat2+0x11b/0x1d0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #5 (&cmd->lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x193/0x1060 kernel/locking/mutex.c:760 nbd_queue_rq+0xbd/0x12d0 drivers/block/nbd.c:1196 blk_mq_dispatch_rq_list+0x416/0x1e20 block/blk-mq.c:2120 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline] __blk_mq_sched_dispatch_requests+0xcb7/0x15f0 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd8/0x1b0 block/blk-mq-sched.c:329 blk_mq_run_hw_queue+0x239/0x670 block/blk-mq.c:2358 blk_mq_dispatch_list+0x514/0x1310 block/blk-mq.c:2919 blk_mq_flush_plug_list block/blk-mq.c:2967 [inline] blk_mq_flush_plug_list+0x130/0x600 block/blk-mq.c:2939 __blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1220 blk_finish_plug block/blk-core.c:1247 [inline] blk_finish_plug block/blk-core.c:1244 [inline] __submit_bio+0x545/0x690 block/blk-core.c:649 __submit_bio_noacct_mq block/blk-core.c:722 [inline] submit_bio_noacct_nocheck+0x660/0xd30 block/blk-core.c:751 submit_bio_noacct+0xc20/0x1ed0 block/blk-core.c:874 submit_bh fs/buffer.c:2829 [inline] block_read_full_folio+0x4db/0x850 fs/buffer.c:2461 filemap_read_folio+0xc5/0x2a0 mm/filemap.c:2413 do_read_cache_folio+0x263/0x5c0 mm/filemap.c:3957 read_mapping_folio include/linux/pagemap.h:991 [inline] read_part_sector+0xd4/0x370 block/partitions/core.c:722 adfspart_check_ICS+0x93/0x940 block/partitions/acorn.c:360 check_partition block/partitions/core.c:141 [inline] blk_add_partitions block/partitions/core.c:589 [inline] bdev_disk_changed+0x720/0x1520 block/partitions/core.c:693 blkdev_get_whole+0x187/0x290 block/bdev.c:748 bdev_open+0x2c7/0xe40 block/bdev.c:957 blkdev_open+0x34e/0x4f0 block/fops.c:694 do_dentry_open+0x97f/0x1530 fs/open.c:965 vfs_open+0x82/0x3f0 fs/open.c:1095 do_open fs/namei.c:3887 [inline] path_openat+0x1de4/0x2cb0 fs/namei.c:4046 do_filp_open+0x20b/0x470 fs/namei.c:4073 do_sys_openat2+0x11b/0x1d0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #4 (set->srcu){.+.+}-{0:0}: srcu_lock_sync include/linux/srcu.h:173 [inline] __synchronize_srcu+0xa1/0x290 kernel/rcu/srcutree.c:1429 blk_mq_wait_quiesce_done block/blk-mq.c:283 [inline] blk_mq_wait_quiesce_done block/blk-mq.c:280 [inline] blk_mq_quiesce_queue block/blk-mq.c:303 [inline] blk_mq_quiesce_queue+0x149/0x1b0 block/blk-mq.c:298 elevator_switch+0x17d/0x810 block/elevator.c:588 elevator_change+0x391/0x580 block/elevator.c:690 elevator_set_default+0x2e9/0x380 block/elevator.c:766 blk_register_queue+0x384/0x4e0 block/blk-sysfs.c:904 __add_disk+0x74a/0xf00 block/genhd.c:528 add_disk_fwnode+0x13f/0x5d0 block/genhd.c:597 add_disk include/linux/blkdev.h:774 [inline] nbd_dev_add+0x783/0xbb0 drivers/block/nbd.c:1973 nbd_init+0x181/0x320 drivers/block/nbd.c:2680 do_one_initcall+0x120/0x6e0 init/main.c:1269 do_initcall_level init/main.c:1331 [inline] do_initcalls init/main.c:1347 [inline] do_basic_setup init/main.c:1366 [inline] kernel_init_freeable+0x5c2/0x910 init/main.c:1579 kernel_init+0x1c/0x2b0 init/main.c:1469 ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #3 (&q->elevator_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x193/0x1060 kernel/locking/mutex.c:760 elevator_change+0x17d/0x580 block/elevator.c:688 elv_iosched_store+0x315/0x3c0 block/elevator.c:823 queue_attr_store+0x26b/0x310 block/blk-sysfs.c:831 sysfs_kf_write+0xef/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x3ac/0x570 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x7d3/0x11d0 fs/read_write.c:686 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&q->q_usage_counter(io)#62){++++}-{0:0}: blk_alloc_queue+0x619/0x760 block/blk-core.c:461 blk_mq_alloc_queue+0x172/0x280 block/blk-mq.c:4400 __blk_mq_alloc_disk+0x29/0x120 block/blk-mq.c:4447 nbd_dev_add+0x492/0xbb0 drivers/block/nbd.c:1943 nbd_init+0x181/0x320 drivers/block/nbd.c:2680 do_one_initcall+0x120/0x6e0 init/main.c:1269 do_initcall_level init/main.c:1331 [inline] do_initcalls init/main.c:1347 [inline] do_basic_setup init/main.c:1366 [inline] kernel_init_freeable+0x5c2/0x910 init/main.c:1579 kernel_init+0x1c/0x2b0 init/main.c:1469 ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #1 (fs_reclaim){+.+.}-{0:0}: __fs_reclaim_acquire mm/page_alloc.c:4234 [inline] fs_reclaim_acquire+0x102/0x150 mm/page_alloc.c:4248 might_alloc include/linux/sched/mm.h:318 [inline] slab_pre_alloc_hook mm/slub.c:4142 [inline] slab_alloc_node mm/slub.c:4220 [inline] kmem_cache_alloc_noprof+0x53/0x3b0 mm/slub.c:4247 __kernfs_iattrs+0x124/0x3e0 fs/kernfs/inode.c:36 kernfs_iattrs fs/kernfs/inode.c:61 [inline] __kernfs_setattr+0x4d/0x3c0 fs/kernfs/inode.c:74 kernfs_iop_setattr+0xda/0x120 fs/kernfs/inode.c:128 notify_change+0x6a6/0x1230 fs/attr.c:552 do_truncate+0x1d7/0x230 fs/open.c:68 handle_truncate fs/namei.c:3508 [inline] do_open fs/namei.c:3891 [inline] path_openat+0x2678/0x2cb0 fs/namei.c:4046 do_filp_open+0x20b/0x470 fs/namei.c:4073 do_sys_openat2+0x11b/0x1d0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&root->kernfs_iattr_rwsem){++++}-{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+0x12a6/0x1ce0 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 down_write+0x92/0x200 kernel/locking/rwsem.c:1590 kernfs_unlink_sibling+0xa3/0x320 fs/kernfs/dir.c:424 __kernfs_remove+0x2c0/0x8a0 fs/kernfs/dir.c:1514 kernfs_remove_by_name_ns+0x68/0x110 fs/kernfs/dir.c:1717 kernfs_remove_by_name include/linux/kernfs.h:633 [inline] cgroup_rm_file kernel/cgroup/cgroup.c:1735 [inline] cgroup_addrm_files+0x82c/0xc20 kernel/cgroup/cgroup.c:4384 css_clear_dir+0x1da/0x290 kernel/cgroup/cgroup.c:1754 cgroup_destroy_locked+0x3a4/0x710 kernel/cgroup/cgroup.c:6086 cgroup_rmdir+0x35/0x2b0 kernel/cgroup/cgroup.c:6126 kernfs_iop_rmdir+0x106/0x170 fs/kernfs/dir.c:1286 vfs_rmdir fs/namei.c:4461 [inline] vfs_rmdir+0x203/0x690 fs/namei.c:4438 do_rmdir+0x2e8/0x3c0 fs/namei.c:4516 __do_sys_rmdir fs/namei.c:4535 [inline] __se_sys_rmdir fs/namei.c:4533 [inline] __x64_sys_rmdir+0xc5/0x110 fs/namei.c:4533 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 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: &root->kernfs_iattr_rwsem --> cpuhp_state_mutex --> &root->kernfs_rwsem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&root->kernfs_rwsem); lock(cpuhp_state_mutex); lock(&root->kernfs_rwsem); lock(&root->kernfs_iattr_rwsem); *** DEADLOCK *** 5 locks held by syz.1.2932/20562: #0: ffff888034472428 (sb_writers#9){.+.+}-{0:0}, at: do_rmdir+0x1e2/0x3c0 fs/namei.c:4504 #1: ffff88805e49a988 (&type->i_mutex_dir_key#6/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:915 [inline] #1: ffff88805e49a988 (&type->i_mutex_dir_key#6/1){+.+.}-{4:4}, at: do_rmdir+0x233/0x3c0 fs/namei.c:4508 #2: ffff888059085568 (&type->i_mutex_dir_key#6){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #2: ffff888059085568 (&type->i_mutex_dir_key#6){++++}-{4:4}, at: vfs_rmdir fs/namei.c:4450 [inline] #2: ffff888059085568 (&type->i_mutex_dir_key#6){++++}-{4:4}, at: vfs_rmdir+0xe9/0x690 fs/namei.c:4438 #3: ffffffff8e61bec8 (cgroup_mutex){+.+.}-{4:4}, at: cgroup_lock include/linux/cgroup.h:387 [inline] #3: ffffffff8e61bec8 (cgroup_mutex){+.+.}-{4:4}, at: cgroup_kn_lock_live+0x116/0x520 kernel/cgroup/cgroup.c:1709 #4: ffff88801caf0188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_drain+0x29c/0x570 fs/kernfs/dir.c:527 stack backtrace: CPU: 1 UID: 0 PID: 20562 Comm: syz.1.2932 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2043 check_noncircular+0x14c/0x170 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+0x12a6/0x1ce0 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 down_write+0x92/0x200 kernel/locking/rwsem.c:1590 kernfs_unlink_sibling+0xa3/0x320 fs/kernfs/dir.c:424 __kernfs_remove+0x2c0/0x8a0 fs/kernfs/dir.c:1514 kernfs_remove_by_name_ns+0x68/0x110 fs/kernfs/dir.c:1717 kernfs_remove_by_name include/linux/kernfs.h:633 [inline] cgroup_rm_file kernel/cgroup/cgroup.c:1735 [inline] cgroup_addrm_files+0x82c/0xc20 kernel/cgroup/cgroup.c:4384 css_clear_dir+0x1da/0x290 kernel/cgroup/cgroup.c:1754 cgroup_destroy_locked+0x3a4/0x710 kernel/cgroup/cgroup.c:6086 cgroup_rmdir+0x35/0x2b0 kernel/cgroup/cgroup.c:6126 kernfs_iop_rmdir+0x106/0x170 fs/kernfs/dir.c:1286 vfs_rmdir fs/namei.c:4461 [inline] vfs_rmdir+0x203/0x690 fs/namei.c:4438 do_rmdir+0x2e8/0x3c0 fs/namei.c:4516 __do_sys_rmdir fs/namei.c:4535 [inline] __se_sys_rmdir fs/namei.c:4533 [inline] __x64_sys_rmdir+0xc5/0x110 fs/namei.c:4533 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fef7b78eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fef7c6d0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 00007fef7b9e6180 RCX: 00007fef7b78eec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000080 RBP: 00007fef7b811f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fef7b9e6218 R14: 00007fef7b9e6180 R15: 00007ffc84e89908