INFO: task syz.2.73:6168 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.73 state:D stack:27272 pid:6168 tgid:6168 ppid:5827 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 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 filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline] page_cache_ra_order+0x3a2/0xe70 mm/readahead.c:494 do_sync_mmap_readahead+0x66a/0x870 mm/filemap.c:3354 filemap_fault+0x6bc/0x12b0 mm/filemap.c:3503 __do_fault+0x138/0x390 mm/memory.c:5324 do_shared_fault mm/memory.c:5806 [inline] do_fault mm/memory.c:5880 [inline] do_pte_missing mm/memory.c:4405 [inline] handle_pte_fault mm/memory.c:6221 [inline] __handle_mm_fault+0x1842/0x5440 mm/memory.c:6363 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6532 do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f314cf56b2d RSP: 002b:00007ffda12daef8 EFLAGS: 00010283 RAX: 00002000000001c0 RBX: 0000000000000004 RCX: ffffffffffffffaf RDX: 0000000000000050 RSI: 0000001b2f820c54 RDI: 00002000000001c0 RBP: 00007f314d1e7da0 R08: 0000001b2fc20000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: 00007f314d1e5fac R13: 00007ffda12daff0 R14: fffffffffffffffe R15: 00007ffda12db010 INFO: task syz.2.73:6169 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.73 state:D stack:26568 pid:6169 tgid:6168 ppid:5827 task_flags:0x440140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 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 filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline] page_cache_ra_order+0x3a2/0xe70 mm/readahead.c:494 do_sync_mmap_readahead+0x66a/0x870 mm/filemap.c:3354 filemap_fault+0x6bc/0x12b0 mm/filemap.c:3503 __do_fault+0x138/0x390 mm/memory.c:5324 do_read_fault mm/memory.c:5742 [inline] do_fault mm/memory.c:5876 [inline] do_pte_missing mm/memory.c:4405 [inline] handle_pte_fault mm/memory.c:6221 [inline] __handle_mm_fault+0x35dc/0x5440 mm/memory.c:6363 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6532 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x1650/0x29f0 mm/gup.c:1428 populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1860 __mm_populate+0x24c/0x380 mm/gup.c:1963 mm_populate include/linux/mm.h:3486 [inline] vm_mmap_pgoff+0x387/0x4d0 mm/util.c:586 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604 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: 0033:0x7f314cf8eec9 RSP: 002b:00007f314de9a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f314d1e5fa0 RCX: 00007f314cf8eec9 RDX: 0000000001000002 RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007f314d011f91 R08: 000000000000000e R09: 000000002c93a000 R10: 0000000000028011 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f314d1e6038 R14: 00007f314d1e5fa0 R15: 00007ffda12dad98 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:3/50: #0: ffff88802f3f6148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88802f3f6148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90000bb7ba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90000bb7ba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f4e65c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f4e65c8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194 3 locks held by kworker/u8:8/3513: #0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000b837ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000b837ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f4e65c8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by getty/5587: #0: ffff88814d4360a0 (&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 2 locks held by kworker/0:4/5914: 3 locks held by syz.1.38/6045: 1 lock held by syz.2.73/6168: #0: ffff888148c614c8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline] #0: ffff888148c614c8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x3a2/0xe70 mm/readahead.c:494 1 lock held by syz.2.73/6169: #0: ffff888148c614c8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline] #0: ffff888148c614c8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x3a2/0xe70 mm/readahead.c:494 1 lock held by syz.4.249/6837: #0: ffff888148c614c8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline] #0: ffff888148c614c8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x3a2/0xe70 mm/readahead.c:494 1 lock held by syz.5.327/7103: #0: ffff888148c614c8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline] #0: ffff888148c614c8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x3a2/0xe70 mm/readahead.c:494 1 lock held by syz.5.327/7104: #0: ffff888148c614c8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline] #0: ffff888148c614c8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x3a2/0xe70 mm/readahead.c:494 1 lock held by syz.6.357/7211: #0: ffff888148c614c8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline] #0: ffff888148c614c8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x3a2/0xe70 mm/readahead.c:494 1 lock held by syz.0.385/7305: #0: ffff888148c614c8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline] #0: ffff888148c614c8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x3a2/0xe70 mm/readahead.c:494 1 lock held by syz.0.385/7308: #0: ffff888148c614c8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline] #0: ffff888148c614c8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x3a2/0xe70 mm/readahead.c:494 2 locks held by syz-executor/7357: #0: ffffffff8f4e65c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8f4e65c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 #1: ffffffff8e142d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8e142d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 1 lock held by syz-executor/7960: 1 lock held by syz.3.589/8169: ============================================= 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:337 [inline] watchdog+0xfa9/0xff0 kernel/hung_task.c:500 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: 9 Comm: kworker/0:0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: events legacy_dvb_usb_read_remote_control RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400 Code: e8 fe 6f a2 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 ef 2e 08 fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07 RSP: 0018:ffffc900000e72b0 EFLAGS: 00000002 RAX: 1ffffffff33a0c00 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffffff99d062d0 R08: ffff888024608237 R09: 1ffff110048c1046 R10: dffffc0000000000 R11: ffffffff851dec60 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff99d06040 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125d22000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0e99a89e9c CR3: 000000007eb6e000 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+0x1a1/0x2f0 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:3257 [inline] serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3342 console_emit_next_record kernel/printk/printk.c:3111 [inline] console_flush_all+0x6f3/0xb10 kernel/printk/printk.c:3199 __console_flush_and_unlock kernel/printk/printk.c:3258 [inline] console_unlock+0xbb/0x190 kernel/printk/printk.c:3298 vprintk_emit+0x4c5/0x590 kernel/printk/printk.c:2423 _printk+0xcf/0x120 kernel/printk/printk.c:2448 m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline] m920x_rc_query+0x2f6/0x830 drivers/media/usb/dvb-usb/m920x.c:-1 legacy_dvb_usb_read_remote_control+0x100/0x470 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 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