INFO: task syz.0.285:7740 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.285 state:D stack:27208 pid:7740 tgid:7737 ppid:5605 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x16ec/0x5620 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7564 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1662 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1739 [inline] __rt_mutex_slowlock_locked+0x1f28/0x2550 kernel/locking/rtmutex.c:1779 __rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1496 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1570 filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline] do_page_cache_ra mm/readahead.c:333 [inline] page_cache_ra_order+0x2a5/0x490 mm/readahead.c:538 filemap_get_pages+0x47c/0x1e70 mm/filemap.c:2696 filemap_splice_read+0x5d3/0xd20 mm/filemap.c:3085 do_splice_read fs/splice.c:980 [inline] splice_direct_to_actor+0x483/0xc80 fs/splice.c:1084 do_splice_direct_actor fs/splice.c:1202 [inline] do_splice_direct+0x19b/0x2a0 fs/splice.c:1228 do_sendfile+0x547/0x7e0 fs/read_write.c:1372 __do_sys_sendfile64 fs/read_write.c:1433 [inline] __se_sys_sendfile64+0x144/0x1a0 fs/read_write.c:1419 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff691c4ce59 RSP: 002b:00007ff68fe7d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007ff691ec6090 RCX: 00007ff691c4ce59 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004 RBP: 00007ff691ce2d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff691ec6128 R14: 00007ff691ec6090 R15: 00007ffd35a1c698 Showing all locks held in the system: 1 lock held by khungtaskd/37: #0: ffffffff8dfc8180 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc8180 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfc8180 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:3/56: #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc9000122fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc9000122fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 3 locks held by kworker/u8:6/126: #0: ffff888032b1f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff888032b1f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc9000388fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc9000388fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4206 5 locks held by kworker/u8:15/1452: #0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc9000689fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc9000689fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffffffff8f348920 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673 #3: ffff888039920160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #3: ffff888039920160 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline] #3: ffff888039920160 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:555 #4: ffff8880560ce310 (&devlink->lock_key#15){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline] #4: ffff8880560ce310 (&devlink->lock_key#15){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline] #4: ffff8880560ce310 (&devlink->lock_key#15){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:555 2 locks held by dhcpcd/5265: #0: ffff88803cd66928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404 #1: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6864 2 locks held by getty/5355: #0: ffff888036fcc0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 3 locks held by syz.1.267/7618: 1 lock held by syz.0.285/7740: #0: ffff888026cd67d8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline] #0: ffff888026cd67d8 (mapping.invalidate_lock){++++}-{4:4}, at: do_page_cache_ra mm/readahead.c:333 [inline] #0: ffff888026cd67d8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x2a5/0x490 mm/readahead.c:538 1 lock held by syz.3.310/8741: #0: ffff888026cd67d8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline] #0: ffff888026cd67d8 (mapping.invalidate_lock){++++}-{4:4}, at: do_page_cache_ra mm/readahead.c:333 [inline] #0: ffff888026cd67d8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x2a5/0x490 mm/readahead.c:538 7 locks held by syz-executor/10765: #0: ffff8880378cc480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2724 [inline] #0: ffff8880378cc480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff8880610fac78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff888028cb4968 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888028cb4968 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ebcfa58 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x710 drivers/net/netdevsim/bus.c:184 #4: ffff88806084b160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #4: ffff88806084b160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076 #5: ffff88802ab80310 (&devlink->lock_key#17){+.+.}-{4:4}, at: nsim_drv_probe+0xc9/0xc30 drivers/net/netdevsim/dev.c:1658 #6: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2162 4 locks held by syz-executor/10827: #0: ffff8880378cc480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2724 [inline] #0: ffff8880378cc480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff8880393cbc78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff888028cb4968 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888028cb4968 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ebcfa58 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x710 drivers/net/netdevsim/bus.c:184 2 locks held by syz-executor/11239: #0: ffffffff8f891368 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8f891368 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8f891368 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4109 1 lock held by syz-executor/11474: #0: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4109 2 locks held by syz-executor/11818: #0: ffffffff8f348920 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575 #1: ffffffff8f357678 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d7/0x840 net/ipv4/ip_tunnel.c:1146 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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:162 [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:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: fb 6d 02 e9 c3 c9 03 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 23 8c 2c 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc900001d7e20 EFLAGS: 00000246 RAX: 00000000000492b1 RBX: ffffffff8199580a RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d605220 RDI: ffffffff8ba74fe0 RBP: ffffc900001d7f10 R08: ffff8880b8933e9b R09: 1ffff110171267d3 R10: dffffc0000000000 R11: ffffed10171267d4 R12: 0000000000000001 R13: 1ffff11003a59000 R14: 0000000000000001 R15: 1ffff11003a59000 FS: 0000000000000000(0000) GS:ffff888126274000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1921f40bde CR3: 000000005ecec000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x36a/0x5f0 kernel/sched/idle.c:352 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147