INFO: task syz.2.41:6211 blocked for more than 143 seconds. Not tainted 6.15.0-rc3-syzkaller-00032-ga79be02bba5c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.41 state:D stack:26440 pid:6211 tgid:6199 ppid:5831 task_flags:0x400040 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 rwsem_down_write_slowpath+0xedd/0x1420 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write_nested+0x1e2/0x220 kernel/locking/rwsem.c:1694 inode_lock_nested include/linux/fs.h:902 [inline] filename_create+0x262/0x510 fs/namei.c:4132 do_mknodat+0x1af/0x600 fs/namei.c:4265 __do_sys_mknod fs/namei.c:4311 [inline] __se_sys_mknod fs/namei.c:4309 [inline] __x64_sys_mknod+0x8c/0xa0 fs/namei.c:4309 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff2f078e969 RSP: 002b:00007ff2f15ca038 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 00007ff2f09b6080 RCX: 00007ff2f078e969 RDX: 0000000000000704 RSI: 0000000000002000 RDI: 0000200000001940 RBP: 00007ff2f0810ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff2f09b6080 R15: 00007ffde4300db8 INFO: task syz.2.41:6216 blocked for more than 144 seconds. Not tainted 6.15.0-rc3-syzkaller-00032-ga79be02bba5c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.41 state:D stack:27944 pid:6216 tgid:6199 ppid:5831 task_flags:0x400040 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 rwsem_down_write_slowpath+0xedd/0x1420 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write_nested+0x1e2/0x220 kernel/locking/rwsem.c:1694 inode_lock_nested include/linux/fs.h:902 [inline] lock_rename fs/namei.c:3265 [inline] do_renameat2+0x653/0x1410 fs/namei.c:5216 __do_sys_rename fs/namei.c:5317 [inline] __se_sys_rename fs/namei.c:5315 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:5315 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff2f078e969 RSP: 002b:00007ff2f15a9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 00007ff2f09b6160 RCX: 00007ff2f078e969 RDX: 0000000000000000 RSI: 0000200000000f40 RDI: 00002000000003c0 RBP: 00007ff2f0810ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007ff2f09b6160 R15: 00007ffde4300db8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6764 2 locks held by kworker/u8:8/1155: #0: ffff8880b8739998 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605 #1: ffff8880b8723b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x41f/0x7a0 kernel/sched/psi.c:987 4 locks held by kworker/u8:11/3021: #0: ffff888141692948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888141692948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000b18fc60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000b18fc60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffff8880442ec0e0 (&type->s_umount_key#51){++++}-{4:4}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff88805c0de730 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x2a6/0x600 fs/jfs/inode.c:102 2 locks held by getty/5587: #0: ffff888031c6a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900033262f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x5bb/0x1700 drivers/tty/n_tty.c:2222 4 locks held by syz.2.41/6200: 2 locks held by syz.2.41/6211: #0: ffff8880442ec420 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:556 #1: ffff88805c0deae0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #1: ffff88805c0deae0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x262/0x510 fs/namei.c:4132 2 locks held by syz.2.41/6216: #0: ffff8880442ec420 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:556 #1: ffff88805c0deae0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #1: ffff88805c0deae0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3265 [inline] #1: ffff88805c0deae0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: do_renameat2+0x653/0x1410 fs/namei.c:5216 1 lock held by syz-executor/6378: #0: ffffffff8ed43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #0: ffffffff8ed43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x384/0x830 kernel/rcu/tree_exp.h:998 2 locks held by syz.7.192/7608: #0: ffff8880442ec0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880442ec0e0 (&type->s_umount_key#51){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff888142f2a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff888142f2a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x270/0xb50 fs/fs-writeback.c:2831 2 locks held by syz.3.204/7817: #0: ffff8880442ec0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880442ec0e0 (&type->s_umount_key#51){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff888142f2a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff888142f2a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x270/0xb50 fs/fs-writeback.c:2831 2 locks held by syz.0.215/7938: #0: ffff8880442ec0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880442ec0e0 (&type->s_umount_key#51){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff888142f2a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff888142f2a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x270/0xb50 fs/fs-writeback.c:2831 5 locks held by syz-executor/8211: #0: ffff8880240d0420 (sb_writers#9){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #0: ffff8880240d0420 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x23f/0xd10 fs/read_write.c:680 #1: ffff8880442c8c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e2/0x510 fs/kernfs/file.c:325 #2: ffffffff8ed75268 (cgroup_mutex){+.+.}-{4:4}, at: cgroup_lock include/linux/cgroup.h:369 [inline] #2: ffffffff8ed75268 (cgroup_mutex){+.+.}-{4:4}, at: cgroup_kn_lock_live+0x134/0x220 kernel/cgroup/cgroup.c:1675 #3: ffffffff8ebd68f0 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2478 [inline] #3: ffffffff8ebd68f0 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x1a2/0x660 kernel/cgroup/cgroup.c:2982 #4: ffffffff8ed75450 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2480 [inline] #4: ffffffff8ed75450 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x1b7/0x660 kernel/cgroup/cgroup.c:2982 2 locks held by syz.1.222/8453: #0: ffff8880442ec0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880442ec0e0 (&type->s_umount_key#51){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff888142f2a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff888142f2a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x270/0xb50 fs/fs-writeback.c:2831 3 locks held by syz.9.253/8490: 2 locks held by sed/8528: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc3-syzkaller-00032-ga79be02bba5c #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:437 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 8211 Comm: syz-executor Not tainted 6.15.0-rc3-syzkaller-00032-ga79be02bba5c #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__lock_acquire+0xabd/0xd80 kernel/locking/lockdep.c:5232 Code: 83 3d ca 78 c0 0e 00 75 19 90 48 c7 c7 04 10 62 8e 48 c7 c6 6a 7e 54 8e e8 50 a0 e3 ff 90 0f 0b 90 90 90 31 c0 48 83 78 40 00 <0f> 84 b8 01 00 00 4c 89 ef 48 89 de 8b 54 24 10 48 89 e9 e8 1b 44 RSP: 0018:ffffc90003b37cc0 EFLAGS: 00000086 RAX: ffffffff940d9c38 RBX: ffff88802f51a940 RCX: 00000000fc31daf3 RDX: 00000000cb65f367 RSI: 00000000d03be5b4 RDI: 0000000000000002 RBP: 5a4fab0e787bfc02 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000037bf6944 R13: ffff88802f519e00 R14: ffff88802f51a960 R15: 000000002318a400 FS: 0000555559f5f500(0000) GS:ffff8881250cf000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f66d43935e8 CR3: 0000000046748000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] dput+0x54/0x2b0 fs/dcache.c:895 done_path_create fs/namei.c:4169 [inline] do_mkdirat+0x2b7/0x3f0 fs/namei.c:4397 __do_sys_mkdirat fs/namei.c:4409 [inline] __se_sys_mkdirat fs/namei.c:4407 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4407 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9bc578d1d7 Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 02 01 00 00 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:00007ffded1df738 EFLAGS: 00000202 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007ffded1df790 RCX: 00007f9bc578d1d7 RDX: 00000000000001ff RSI: 00007ffded1df790 RDI: 00000000ffffff9c RBP: 0000000000000003 R08: 0000000000000003 R09: 00007ffded1df4d7 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007f9bc597d260 R14: 0000000000000003 R15: 00007ffded1df7d0