INFO: task syz.7.1394:8843 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.1394 state:D stack:29184 pid:8843 ppid:8384 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747 __fdget_pos+0x2ae/0x360 fs/file.c:1038 fdget_pos include/linux/file.h:74 [inline] __do_sys_getdents fs/readdir.c:282 [inline] __se_sys_getdents+0xbe/0x250 fs/readdir.c:271 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fb31f98f749 RSP: 002b:00007fb31dbd5038 EFLAGS: 00000246 ORIG_RAX: 000000000000004e RAX: ffffffffffffffda RBX: 00007fb31fbe6090 RCX: 00007fb31f98f749 RDX: 00000000000000bb RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007fb31fa13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb31fbe6128 R14: 00007fb31fbe6090 R15: 00007ffe2ede6e28 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b630 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2be50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by getty/4026: #0: ffff88802f5c7098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 3 locks held by kworker/0:6/5373: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90003337d00 ( fqdir_free_work ){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8cb30840 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x600 kernel/rcu/tree.c:4023 6 locks held by kworker/u4:19/6085: #0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004ef7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd34a10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594 #3: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: caif_exit_net+0x66/0x490 net/caif/caif_dev.c:527 #4: ffff888028c3ab80 (&caifn->caifdevs.lock){+.+.}-{3:3}, at: caif_exit_net+0x79/0x490 net/caif/caif_dev.c:528 #5: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #5: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 2 locks held by kworker/0:13/8267: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000eb0fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 3 locks held by kworker/0:14/8268: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000ed97d00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #2: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962 6 locks held by syz.7.1394/8838: 1 lock held by syz.7.1394/8843: #0: ffff88807bd85268 (&f->f_pos_lock){+.+.}-{3:3} , at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 1 lock held by syz-executor/8982: #0: ffff88807974c0e0 ( &type->s_umount_key #106){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 1 lock held by syz-executor/10250: #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147 6 locks held by syz.1.1809/10290: #0: ffffffff8dd34a10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:504 #1: ffffffff8db08590 (devices_rwsem){++++}-{3:3}, at: rdma_dev_init_net+0x193/0x270 drivers/infiniband/core/device.c:1188 #2: ffffffff8db08750 (rdma_nets_rwsem){++++}-{3:3}, at: rdma_dev_init_net+0x1cb/0x270 drivers/infiniband/core/device.c:1193 #3: ffff8880729f4f20 (&device->compat_devs_mutex){+.+.}-{3:3}, at: add_one_compat_dev+0xee/0x5c0 drivers/infiniband/core/device.c:952 #4: ffff8880729f5150 (&rxe->usdev_lock){+.+.}-{3:3}, at: rxe_query_port+0x46/0x190 drivers/infiniband/sw/rxe/rxe_verbs.c:37 #5: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: ib_get_eth_speed+0x149/0x4c0 drivers/infiniband/core/verbs.c:1897 1 lock held by dhcpcd/10308: #0: ffff8880186c4130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1792 [inline] (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xce0 net/packet/af_packet.c:3248 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8838 Comm: syz.7.1394 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:io_serial_out+0x78/0xb0 drivers/tty/serial/8250/8250_port.c:468 Code: 78 09 fd 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 30 a7 59 fd 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d c3 44 89 f9 80 e1 07 38 c1 7c aa 4c 89 ff RSP: 0018:ffffc90003437090 EFLAGS: 00000002 RAX: 0000000000000034 RBX: 0000000000000034 RCX: 0000000000000000 RDX: 00000000000003f8 RSI: 000000000007ffff RDI: 0000000000080000 RBP: 00000000000003f8 R08: dffffc0000000000 R09: ffffed100485e047 R10: ffffed100485e047 R11: 1ffff1100485e046 R12: dffffc0000000000 R13: ffffffff96c2be05 R14: ffffffff96f704c0 R15: 0000000000000000 FS: 00007fb31dbf66c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc6cdc0f32 CR3: 000000004ea53000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_out drivers/tty/serial/8250/8250.h:122 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline] serial8250_console_write+0x10fa/0x17a0 drivers/tty/serial/8250/8250_port.c:3473 call_console_driver kernel/printk/printk.c:1977 [inline] console_emit_next_record+0x947/0xc90 kernel/printk/printk.c:2777 console_flush_all kernel/printk/printk.c:-1 [inline] console_unlock+0x223/0x630 kernel/printk/printk.c:2906 vprintk_emit+0x489/0x680 kernel/printk/printk.c:2303 _printk+0xcc/0x110 kernel/printk/printk.c:2328 _erofs_err+0x11f/0x170 fs/erofs/super.c:35 z_erofs_pcluster_readmore+0x367/0x4f0 fs/erofs/zdata.c:1658 z_erofs_read_folio+0x23b/0x5b0 fs/erofs/zdata.c:1681 filemap_read_folio+0x160/0x760 mm/filemap.c:2490 do_read_cache_folio+0x2a0/0x760 mm/filemap.c:3627 erofs_bread+0x18e/0x670 fs/erofs/data.c:50 erofs_readdir+0x2a3/0xb20 fs/erofs/dir.c:65 iterate_dir+0x218/0x560 fs/readdir.c:-1 __do_sys_getdents fs/readdir.c:286 [inline] __se_sys_getdents+0xe5/0x250 fs/readdir.c:271 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fb31f98f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007fb31dbf6038 EFLAGS: 00000246 ORIG_RAX: 000000000000004e RAX: ffffffffffffffda RBX: 00007fb31fbe5fa0 RCX: 00007fb31f98f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007fb31fa13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb31fbe6038 R14: 00007fb31fbe5fa0 R15: 00007ffe2ede6e28