INFO: task syz.1.73:6365 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.73 state:D stack:27112 pid:6365 tgid:6354 ppid:5805 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 __rwbase_read_lock+0xbc/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1466 [inline] down_read+0x127/0x1f0 kernel/locking/rwsem.c:1539 inode_lock_shared include/linux/fs.h:995 [inline] lookup_slow+0x46/0x70 fs/namei.c:1832 walk_component fs/namei.c:2151 [inline] link_path_walk+0x935/0xea0 fs/namei.c:2519 path_parentat fs/namei.c:2723 [inline] __filename_parentat+0x246/0x670 fs/namei.c:2747 filename_parentat fs/namei.c:2765 [inline] filename_create+0xd2/0x3c0 fs/namei.c:4207 do_mkdirat+0xa0/0x590 fs/namei.c:4478 __do_sys_mkdirat fs/namei.c:4503 [inline] __se_sys_mkdirat fs/namei.c:4501 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4501 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: 0033:0x7f546534efc9 RSP: 002b:00007f546356c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f54655a6180 RCX: 00007f546534efc9 RDX: 00000000000001ff RSI: 0000200000000000 RDI: ffffffffffffff9c RBP: 00007f54653d1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f54655a6218 R14: 00007f54655a6180 R15: 00007ffdc50d4668 INFO: task syz.1.73:6366 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.73 state:D stack:28136 pid:6366 tgid:6354 ppid:5805 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 __rwbase_read_lock+0xbc/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1466 [inline] down_read+0x127/0x1f0 kernel/locking/rwsem.c:1539 inode_lock_shared include/linux/fs.h:995 [inline] lookup_slow+0x46/0x70 fs/namei.c:1832 walk_component fs/namei.c:2151 [inline] link_path_walk+0x935/0xea0 fs/namei.c:2519 path_lookupat+0x97/0x430 fs/namei.c:2675 do_o_path+0x97/0x1f0 fs/namei.c:4105 path_openat+0x312b/0x3840 fs/namei.c:4127 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 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: 0033:0x7f546534efc9 RSP: 002b:00007f5463149038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f54655a6270 RCX: 00007f546534efc9 RDX: 0000000000200002 RSI: 0000200000000000 RDI: ffffffffffffff9c RBP: 00007f54653d1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f54655a6308 R14: 00007f54655a6270 R15: 00007ffdc50d4668 Showing all locks held in the system: 4 locks held by pr/legacy/17: 1 lock held by khungtaskd/38: #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:7/1171: #0: ffff8881436e9138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff8881436e9138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90004f57ba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90004f57ba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff88803647a0d0 (&type->s_umount_key#58){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562 #3: ffff88805d736368 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 1 lock held by dhcpcd/5468: #0: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50 net/ipv4/devinet.c:1120 2 locks held by getty/5563: #0: ffff88823bf308a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5804: #0: ffff88803cfa20d0 (&type->s_umount_key#61){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88803cfa20d0 (&type->s_umount_key#61){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88803cfa20d0 (&type->s_umount_key#61){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 4 locks held by kworker/1:4/5872: 4 locks held by syz.1.73/6355: 1 lock held by syz.1.73/6365: #0: ffff88805d736738 (&type->i_mutex_dir_key#11){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:995 [inline] #0: ffff88805d736738 (&type->i_mutex_dir_key#11){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832 1 lock held by syz.1.73/6366: #0: ffff88805d736738 (&type->i_mutex_dir_key#11){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:995 [inline] #0: ffff88805d736738 (&type->i_mutex_dir_key#11){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832 3 locks held by kworker/u8:25/7177: #0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9001f45fba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9001f45fba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 4 locks held by kworker/u8:26/7178: 2 locks held by syz-executor/7777: #0: ffffffff8e201220 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e201220 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e201220 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 3 locks held by syz.5.304/8190: 2 locks held by syz.0.307/8196: 2 locks held by syz-executor/8198: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(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:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400 Code: e8 2e 9b b2 fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 bf 52 14 fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 da 4c bf 05 cc 44 89 f9 80 e1 07 RSP: 0018:ffffc90000167870 EFLAGS: 00000202 RAX: 1ffffffff3218b00 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff990c61d0 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff850c7200 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff990c5f40 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888126bc2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4d2918f742 CR3: 0000000031924000 CR4: 00000000003526f0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:137 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline] wait_for_lsr+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:1961 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3275 [inline] serial8250_console_write+0x1341/0x1b40 drivers/tty/serial/8250/8250_port.c:3342 console_emit_next_record kernel/printk/printk.c:3091 [inline] console_flush_all+0x666/0xb40 kernel/printk/printk.c:3199 __console_flush_and_unlock+0x9b/0x160 kernel/printk/printk.c:3258 legacy_kthread_func+0x13b/0x1a0 kernel/printk/printk.c:3611 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245