INFO: task syz.1.3760:21899 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.3760 state:D stack:28616 pid:21899 tgid:21887 ppid:16400 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5257 [inline] __schedule+0x14bc/0x5030 kernel/sched/core.c:6864 __schedule_loop kernel/sched/core.c:6946 [inline] schedule+0x165/0x360 kernel/sched/core.c:6961 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7018 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:1072 [inline] lock_rename fs/namei.c:3681 [inline] __start_renaming+0x148/0x410 fs/namei.c:3777 do_renameat2+0x399/0x8e0 fs/namei.c:5991 __do_sys_rename fs/namei.c:6059 [inline] __se_sys_rename fs/namei.c:6057 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:6057 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: 0033:0x7f38e1d8f749 RSP: 002b:00007f38e2c99038 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 00007f38e1fe6090 RCX: 00007f38e1d8f749 RDX: 0000000000000000 RSI: 0000200000000440 RDI: 0000200000000340 RBP: 00007f38e1e13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f38e1fe6128 R14: 00007f38e1fe6090 R15: 00007ffe8d89a788 INFO: task syz.1.3760:21904 blocked for more than 146 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.3760 state:D stack:28264 pid:21904 tgid:21887 ppid:16400 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5257 [inline] __schedule+0x14bc/0x5030 kernel/sched/core.c:6864 __schedule_loop kernel/sched/core.c:6946 [inline] schedule+0x165/0x360 kernel/sched/core.c:6961 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7018 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:1042 [inline] lookup_slow+0x46/0x70 fs/namei.c:1871 walk_component fs/namei.c:2190 [inline] link_path_walk+0xb4e/0x11f0 fs/namei.c:2558 path_openat+0x29f/0x3d90 fs/namei.c:4752 do_filp_open+0x1fa/0x410 fs/namei.c:4783 do_sys_openat2+0x121/0x1c0 fs/open.c:1432 do_sys_open fs/open.c:1447 [inline] __do_sys_openat fs/open.c:1463 [inline] __se_sys_openat fs/open.c:1458 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1458 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: 0033:0x7f38e1d8f749 RSP: 002b:00007f38e2c57038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f38e1fe6270 RCX: 00007f38e1d8f749 RDX: 0000000000143041 RSI: 0000200000000040 RDI: ffffffffffffff9c RBP: 00007f38e1e13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f38e1fe6308 R14: 00007f38e1fe6270 R15: 00007ffe8d89a788 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5586: #0: ffff888030d670a0 (&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 3 locks held by syz.1.3760/21889: 2 locks held by syz.1.3760/21899: #0: ffff888030432420 (sb_writers#29){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:509 #1: ffff8880358bd3b0 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline] #1: ffff8880358bd3b0 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3681 [inline] #1: ffff8880358bd3b0 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3777 1 lock held by syz.1.3760/21904: #0: ffff8880358bd3b0 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1042 [inline] #0: ffff8880358bd3b0 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1871 2 locks held by dhcpcd/23468: #0: ffff8880a1440208 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff8880a1440208 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline] #0: ffff8880a1440208 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1459 #1: ffffffff8df43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8df43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xfb5/0x1000 kernel/hung_task.c:515 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:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6240 Comm: kworker/u8:21 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: writeback wb_update_bandwidth_workfn RIP: 0010:__set_next_task_fair+0x1db/0x390 kernel/sched/fair.c:13549 Code: 2b 48 b8 00 00 00 00 00 fc ff df 41 80 3c 04 00 74 08 48 89 ef e8 65 f2 93 00 4c 89 7d 00 48 8b 5c 24 08 80 7c 24 04 00 74 41 <4d> 8d be d1 00 00 00 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc RSP: 0018:ffffc900052e76f8 EFLAGS: 00000002 RAX: dffffc0000000000 RBX: ffff8880b873a900 RCX: dffffc0000000000 RDX: ffff88807d5edc40 RSI: ffff8880b873b4f0 RDI: ffff888076b25c40 RBP: ffff8880b873b4f0 R08: ffff88807d5edc27 R09: 0000000000000000 R10: ffff88807d5edc18 R11: ffffffff81956150 R12: 1ffff110170e769e R13: ffff88807d5edc40 R14: ffff888076b25b80 R15: ffff888076b25c40 FS: 0000000000000000(0000) GS:ffff888125fba000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2acd5b6ad8 CR3: 000000000dd38000 CR4: 00000000003526f0 Call Trace: put_prev_set_next_task kernel/sched/sched.h:2645 [inline] pick_next_task kernel/sched/core.c:6199 [inline] __schedule+0x3961/0x5030 kernel/sched/core.c:6806 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7048 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7072 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irq+0x45/0x50 kernel/locking/spinlock.c:202 process_one_work+0x739/0x15e0 kernel/workqueue.c:3230 process_scheduled_works kernel/workqueue.c:3344 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425 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:246