INFO: task syz.2.2975:17278 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.2975 state:D stack:28744 pid:17278 tgid:17276 ppid:5821 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5264 [inline] __schedule+0x1848/0x4ec0 kernel/sched/core.c:6872 __schedule_loop kernel/sched/core.c:6954 [inline] schedule+0x165/0x360 kernel/sched/core.c:6969 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7026 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write_nested+0x1b5/0x200 kernel/locking/rwsem.c:1707 inode_lock_nested include/linux/fs.h:1096 [inline] filename_create+0x1f8/0x3c0 fs/namei.c:4226 do_mkdirat+0xa0/0x650 fs/namei.c:4478 __do_sys_mkdir fs/namei.c:4508 [inline] __se_sys_mkdir fs/namei.c:4506 [inline] __x64_sys_mkdir+0x6c/0x80 fs/namei.c:4506 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f73f838f6c9 RSP: 002b:00007f73f65f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007f73f85e6090 RCX: 00007f73f838f6c9 RDX: 0000000000000000 RSI: 0000000000000105 RDI: 0000200000000500 RBP: 00007f73f8411f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f73f85e6128 R14: 00007f73f85e6090 R15: 00007fff40ba4af8 INFO: task syz.2.2975:17279 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.2975 state:D stack:28744 pid:17279 tgid:17276 ppid:5821 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5264 [inline] __schedule+0x1848/0x4ec0 kernel/sched/core.c:6872 __schedule_loop kernel/sched/core.c:6954 [inline] schedule+0x165/0x360 kernel/sched/core.c:6969 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7026 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write_nested+0x1b5/0x200 kernel/locking/rwsem.c:1707 inode_lock_nested include/linux/fs.h:1096 [inline] do_rmdir+0x1b2/0x550 fs/namei.c:4595 __do_sys_rmdir fs/namei.c:4622 [inline] __se_sys_rmdir fs/namei.c:4620 [inline] __x64_sys_rmdir+0x47/0x50 fs/namei.c:4620 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f73f838f6c9 RSP: 002b:00007f73f65d5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 00007f73f85e6180 RCX: 00007f73f838f6c9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000100 RBP: 00007f73f8411f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f73f85e6218 R14: 00007f73f85e6180 R15: 00007fff40ba4af8 INFO: task syz.2.2975:17280 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.2975 state:D stack:25808 pid:17280 tgid:17276 ppid:5821 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5264 [inline] __schedule+0x1848/0x4ec0 kernel/sched/core.c:6872 __schedule_loop kernel/sched/core.c:6954 [inline] schedule+0x165/0x360 kernel/sched/core.c:6969 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7026 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1539 inode_lock_shared include/linux/fs.h:1066 [inline] lookup_slow+0x46/0x70 fs/namei.c:1832 walk_component+0x2d2/0x400 fs/namei.c:2151 lookup_last fs/namei.c:2652 [inline] path_lookupat+0x163/0x430 fs/namei.c:2676 filename_lookup+0x212/0x570 fs/namei.c:2705 kern_path+0x35/0x50 fs/namei.c:2863 unix_find_bsd net/unix/af_unix.c:1216 [inline] unix_find_other+0x183/0xad0 net/unix/af_unix.c:1278 unix_stream_connect+0x429/0x1010 net/unix/af_unix.c:1679 p9_fd_create_unix+0x210/0x400 net/9p/trans_fd.c:960 p9_client_create+0x400/0xc50 net/9p/client.c:894 v9fs_session_init+0x46/0xdf0 fs/9p/v9fs.c:422 v9fs_get_tree+0xb7/0xa60 fs/9p/vfs_super.c:97 vfs_get_tree+0x92/0x2b0 fs/super.c:1752 fc_mount fs/namespace.c:1198 [inline] do_new_mount_fc fs/namespace.c:3641 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3717 do_mount fs/namespace.c:4040 [inline] __do_sys_mount fs/namespace.c:4228 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4205 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f73f838f6c9 RSP: 002b:00007f73f61b2038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f73f85e6270 RCX: 00007f73f838f6c9 RDX: 00002000000000c0 RSI: 0000200000000040 RDI: 0000200000000080 RBP: 00007f73f8411f91 R08: 0000200000000200 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f73f85e6308 R14: 00007f73f85e6270 R15: 00007fff40ba4af8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3b720 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3b720 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df3b720 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5580: #0: ffff88814e2dd0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 4 locks held by syz.2.2975/17277: 2 locks held by syz.2.2975/17278: #0: ffff888054928420 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:498 #1: ffff88805607a230 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1096 [inline] #1: ffff88805607a230 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: filename_create+0x1f8/0x3c0 fs/namei.c:4226 2 locks held by syz.2.2975/17279: #0: ffff888054928420 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:498 #1: ffff88805607a230 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1096 [inline] #1: ffff88805607a230 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: do_rmdir+0x1b2/0x550 fs/namei.c:4595 1 lock held by syz.2.2975/17280: #0: ffff88805607a230 (&type->i_mutex_dir_key#13){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1066 [inline] #0: ffff88805607a230 (&type->i_mutex_dir_key#13){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832 3 locks held by syz.3.3578/19509: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:336 [inline] watchdog+0xfa9/0xff0 kernel/hung_task.c:499 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 2890 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:__rb_change_child include/linux/rbtree_augmented.h:200 [inline] RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:242 [inline] RIP: 0010:rb_erase_augmented include/linux/rbtree_augmented.h:329 [inline] RIP: 0010:rb_erase_augmented_cached include/linux/rbtree_augmented.h:340 [inline] RIP: 0010:__dequeue_entity+0x822/0xc60 kernel/sched/fair.c:859 Code: eb 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 81 fc 91 00 48 89 5c 24 10 4d 89 3e 4d 85 f6 0f 85 5a 01 00 00 eb 36 <43> 80 3c 26 00 74 08 48 89 df e8 5f fc 91 00 48 89 2b 4d 89 fe 48 RSP: 0018:ffffc9000b067368 EFLAGS: 00000046 RAX: ffff888030799f10 RBX: ffff88806ab4e820 RCX: dffffc0000000000 RDX: 0000000000000001 RSI: ffff888030799f00 RDI: ffff888030799f18 RBP: 0000000000000000 R08: ffffffff8f7da977 R09: 1ffffffff1efb52e R10: dffffc0000000000 R11: ffffffff81952160 R12: dffffc0000000000 R13: ffff88806ab4e811 R14: 1ffff1100d569d04 R15: ffff88806ab4e810 FS: 0000000000000000(0000) GS:ffff888125ec2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f72003b4198 CR3: 000000000dd36000 CR4: 00000000003526f0 Call Trace: set_next_entity+0x100/0x690 kernel/sched/fair.c:5473 set_next_task_fair+0x62/0x1d0 kernel/sched/fair.c:13324 put_prev_set_next_task kernel/sched/sched.h:2635 [inline] pick_next_task kernel/sched/core.c:6207 [inline] __schedule+0x3845/0x4ec0 kernel/sched/core.c:6814 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7056 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7080 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 on_each_cpu_cond_mask+0x7a/0x80 kernel/smp.c:1044 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2697 [inline] smp_text_poke_batch_finish+0xb44/0x1130 arch/x86/kernel/alternative.c:2969 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_disable_cpuslocked+0xc5/0x1b0 kernel/jump_label.c:240 static_key_disable+0x1a/0x20 kernel/jump_label.c:248 toggle_allocation_gate+0x1a1/0x240 mm/kfence/core.c:857 process_one_work+0x94a/0x15d0 kernel/workqueue.c:3267 process_scheduled_works kernel/workqueue.c:3350 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3431 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245