INFO: task syz.5.2896:19567 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.2896 state:D stack:24280 pid:19567 tgid:19566 ppid:17951 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5290 [inline] __schedule+0x14db/0x5030 kernel/sched/core.c:6902 __schedule_loop kernel/sched/core.c:6984 [inline] schedule+0x165/0x360 kernel/sched/core.c:6999 io_schedule+0x80/0xd0 kernel/sched/core.c:7828 folio_wait_bit_common+0x6b0/0xb80 mm/filemap.c:1323 folio_lock include/linux/pagemap.h:1170 [inline] release_metapage+0x103/0xac0 fs/jfs/jfs_metapage.c:870 discard_metapage fs/jfs/jfs_metapage.h:88 [inline] __get_metapage+0x9a3/0xde0 fs/jfs/jfs_metapage.c:753 dtSearch+0x591/0x21b0 fs/jfs/jfs_dtree.c:624 jfs_lookup+0x155/0x380 fs/jfs/namei.c:1464 lookup_open fs/namei.c:4454 [inline] open_last_lookups fs/namei.c:4581 [inline] path_openat+0x119c/0x3840 fs/namei.c:4825 do_file_open+0x203/0x440 fs/namei.c:4857 do_sys_openat2+0x105/0x1e0 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f59e6b8f749 RSP: 002b:00007f59e793f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f59e6de5fa0 RCX: 00007f59e6b8f749 RDX: 0000000000101142 RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 00007f59e6c13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f59e6de6038 R14: 00007f59e6de5fa0 R15: 00007ffdac9c5858 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e144ce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e144ce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e144ce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:9/3011: #0: ffff888141afe148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc9000bf0fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 #2: ffff888030c760e0 (&type->s_umount_key#102){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 2 locks held by getty/5577: #0: ffff88814e22b0a0 (&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+0x449/0x1460 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:10/7545: #0: ffff88813fe15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc900044cfc40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 #2: ffff88805c414240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1f7/0x3b0 drivers/net/netdevsim/fib.c:1490 4 locks held by kworker/u8:23/10393: #0: ffff888141afe148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc9000455fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 #2: ffff88814e5dc0e0 (&type->s_umount_key#32){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 #3: ffff88814e5deb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #3: ffff88814e5deb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1820 [inline] #3: ffff88814e5deb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1ca/0x350 fs/ext4/inode.c:3025 1 lock held by syz.5.2896/19567: #0: ffff88807b83bc68 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #0: ffff88807b83bc68 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: open_last_lookups fs/namei.c:4578 [inline] #0: ffff88807b83bc68 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: path_openat+0xb4c/0x3840 fs/namei.c:4825 3 locks held by syz-executor/21644: #0: ffffffff8f51be08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f51be08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f51be08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071 #1: ffff888032fecd48 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2786 [inline] #1: ffff888032fecd48 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] #1: ffff888032fecd48 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: do_setlink+0x388/0x41c0 net/core/rtnetlink.c:3068 #2: ffffffff8e14a2f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #2: ffffffff8e14a2f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x36e/0x6e0 kernel/rcu/tree_exp.h:961 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [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+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x389/0x480 kernel/kthread.c:467 ret_from_fork+0x510/0xa50 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: 21644 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:preempt_count_add+0x6/0x190 kernel/sched/core.c:5748 Code: e8 7f e2 96 00 eb 8a e9 e9 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 53 49 bf 00 00 00 00 00 fc ff df 48 c7 c0 20 c4 ad 99 48 c1 RSP: 0018:ffffc900132c64e0 EFLAGS: 00000002 RAX: 0000000000000002 RBX: 0000000000000899 RCX: 0000000000000000 RDX: 0000000000000269 RSI: ffffffff8be09740 RDI: 0000000000000001 RBP: 0000000000000000 R08: ffff888141bf8237 R09: 1ffff1102837f046 R10: dffffc0000000000 R11: ffffffff8b5d43f0 R12: 1ffffffff33c628a R13: 00000000ffffffff R14: 000002699e4e914e R15: 0000000000000818 FS: 0000555571fd5500(0000) GS:ffff888125bf9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9be05135c0 CR3: 0000000040618000 CR4: 00000000003526f0 Call Trace: delay_tsc+0x65/0xc0 arch/x86/lib/delay.c:79 udelay include/asm-generic/delay.h:62 [inline] wait_for_lsr+0x160/0x2f0 drivers/tty/serial/8250/8250_port.c:1967 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline] serial8250_console_write+0x1301/0x1b60 drivers/tty/serial/8250/8250_port.c:3342 console_emit_next_record kernel/printk/printk.c:3131 [inline] console_flush_one_record kernel/printk/printk.c:3217 [inline] console_flush_all+0x713/0xb00 kernel/printk/printk.c:3291 __console_flush_and_unlock kernel/printk/printk.c:3321 [inline] console_unlock+0xbb/0x190 kernel/printk/printk.c:3361 vprintk_emit+0x47b/0x550 kernel/printk/printk.c:2428 dev_vprintk_emit+0x337/0x3f0 drivers/base/core.c:4914 dev_printk_emit+0xe0/0x130 drivers/base/core.c:4925 __netdev_printk+0x3e1/0x480 net/core/dev.c:12934 netdev_info+0x10a/0x160 net/core/dev.c:12989 netif_change_name+0x863/0x930 net/core/dev.c:1478 do_setlink+0x9f6/0x41c0 net/core/rtnetlink.c:3138 rtnl_changelink net/core/rtnetlink.c:3776 [inline] __rtnl_newlink net/core/rtnetlink.c:3935 [inline] rtnl_newlink+0x161c/0x1c90 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:737 __sock_sendmsg net/socket.c:752 [inline] __sys_sendto+0x3ce/0x540 net/socket.c:2221 __do_sys_sendto net/socket.c:2228 [inline] __se_sys_sendto net/socket.c:2224 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2224 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9bdf7915dc Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b RSP: 002b:00007ffeec0bcde0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f9be05135c0 RCX: 00007f9bdf7915dc RDX: 0000000000000030 RSI: 00007f9be0513610 RDI: 0000000000000006 RBP: 0000000000000000 R08: 00007ffeec0bce34 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000006 R13: 0000000000000000 R14: 00007f9be0513610 R15: 0000000000000000