INFO: task syz.8.6596:23641 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.6596 state:D stack:25032 pid:23641 tgid:23641 ppid:23027 task_flags:0x400040 flags:0x00080003 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] schedule+0x165/0x360 kernel/sched/core.c:7026 request_wait_answer fs/fuse/dev.c:565 [inline] __fuse_request_send fs/fuse/dev.c:579 [inline] __fuse_simple_request+0xf1b/0x18e0 fs/fuse/dev.c:673 fuse_simple_request fs/fuse/fuse_i.h:1244 [inline] fuse_flush+0x5dd/0x810 fs/fuse/file.c:476 filp_flush+0xbd/0x190 fs/open.c:1549 filp_close+0x1d/0x40 fs/open.c:1562 __range_close fs/file.c:767 [inline] __do_sys_close_range fs/file.c:826 [inline] __se_sys_close_range+0x35c/0x650 fs/file.c:790 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7e8afceec9 RSP: 002b:00007ffd91f48678 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: ffffffffffffffda RBX: 00007f7e8b227da0 RCX: 00007f7e8afceec9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f7e8b227da0 R08: 00000000000000cc R09: 0000000891f4896f R10: 00007f7e8b227cb0 R11: 0000000000000246 R12: 000000000012feba R13: 00007ffd91f48770 R14: ffffffffffffffff R15: 00007ffd91f48790 INFO: task syz.5.6649:23772 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.6649 state:D stack:25160 pid:23772 tgid:23772 ppid:13058 task_flags:0x400040 flags:0x00080003 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] schedule+0x165/0x360 kernel/sched/core.c:7026 request_wait_answer fs/fuse/dev.c:565 [inline] __fuse_request_send fs/fuse/dev.c:579 [inline] __fuse_simple_request+0xf1b/0x18e0 fs/fuse/dev.c:673 fuse_simple_request fs/fuse/fuse_i.h:1244 [inline] fuse_flush+0x5dd/0x810 fs/fuse/file.c:476 filp_flush+0xbd/0x190 fs/open.c:1549 filp_close+0x1d/0x40 fs/open.c:1562 __range_close fs/file.c:767 [inline] __do_sys_close_range fs/file.c:826 [inline] __se_sys_close_range+0x35c/0x650 fs/file.c:790 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f356dceeec9 RSP: 002b:00007ffe5710e288 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: ffffffffffffffda RBX: 00007f356df47da0 RCX: 00007f356dceeec9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f356df47da0 R08: 000000000000a47c R09: 000000085710e57f R10: 00007f356df47cb0 R11: 0000000000000246 R12: 0000000000131d2a R13: 00007ffe5710e380 R14: ffffffffffffffff R15: 00007ffe5710e3a0 Showing all locks held in the system: 3 locks held by rcuc/1/28: 5 locks held by ktimers/1/29: 1 lock held by khungtaskd/38: #0: ffffffff8d3aa300 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d3aa300 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d3aa300 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5574: #0: ffff88823bf500a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e762e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222 6 locks held by kworker/u8:32/18072: #0: ffff888019a94138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff888019a94138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90008537bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90008537bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e652460 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820 net/core/net_namespace.c:669 #3: ffff88801bb890d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #3: ffff88801bb890d8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff88801bb890d8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x10a/0x3d0 net/devlink/core.c:506 #4: ffff888027f80300 (&devlink->lock_key#14){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff888027f80300 (&devlink->lock_key#14){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff888027f80300 (&devlink->lock_key#14){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x11c/0x3d0 net/devlink/core.c:506 #5: ffffffff8e65f378 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #5: ffffffff8e65f378 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2142 3 locks held by kworker/u8:38/18079: #0: ffff88813ff29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000a5afbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000a5afbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e65f378 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 5 locks held by syz.7.7075/25118: 2 locks held by syz-executor/25131: #0: ffffffff8e652460 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:576 #1: ffffffff8e65f378 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800 net/ipv4/ip_tunnel.c:1160 1 lock held by syz.7.7091/25181: #0: ffffffff8e65f378 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8e65f378 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3436 1 lock held by syz.6.7098/25209: 1 lock held by syz.1.7099/25216: 1 lock held by syz.2.7100/25213: #0: ffffffff8d267958 (sched_core_mutex){+.+.}-{4:4}, at: sched_core_get+0x52/0x170 kernel/sched/core.c:484 ============================================= 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 08/18/2025 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+0x436/0x7d0 arch/x86/kernel/process.c:148 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: 25205 Comm: syz.6.7098 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0033:0x7f3e8d0681c5 Code: 72 f3 48 83 e8 08 48 39 f2 73 17 66 2e 0f 1f 84 00 00 00 00 00 48 8b 70 f8 48 83 e8 08 48 39 f2 72 f3 48 39 c3 73 3e 48 89 33 <48> 83 c3 08 48 8b 70 f8 48 89 08 48 8b 0b 49 8b 14 24 eb bf 48 39 RSP: 002b:00007fff3816a300 EFLAGS: 00000283 RAX: 00007f3e8cacc750 RBX: 00007f3e8c8f7000 RCX: ffffffff889d0d2f RDX: ffffffff8896b798 RSI: ffffffff818ac052 RDI: 00007f3e8cbfd000 RBP: 00007f3e8c7fd010 R08: 00007f3e8c9fd000 R09: 00007f3e8d3d2000 R10: 00007f3e8c7fd008 R11: 000000000000000a R12: 00007f3e8c7fd008 R13: 0000000000000023 R14: ffffffffffffffff R15: 00007f3e8c7fd008 FS: 00005555599e2500 GS: 0000000000000000