INFO: task syz.6.6665:21375 blocked for more than 147 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.6665 state:D stack:24832 pid:21375 tgid:21375 ppid:19418 task_flags:0x400040 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 request_wait_answer fs/fuse/dev.c:585 [inline] __fuse_request_send fs/fuse/dev.c:599 [inline] __fuse_simple_request+0x121f/0x1c60 fs/fuse/dev.c:693 fuse_simple_request fs/fuse/fuse_i.h:1263 [inline] fuse_flush+0x673/0x8b0 fs/fuse/file.c:494 filp_flush+0xc0/0x190 fs/open.c:1469 filp_close+0x1d/0x40 fs/open.c:1482 __range_close fs/file.c:794 [inline] __do_sys_close_range fs/file.c:855 [inline] __se_sys_close_range+0x3d7/0x900 fs/file.c:819 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f537d28c819 RSP: 002b:00007ffd2a0442e8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: ffffffffffffffda RBX: 00007f537d507da0 RCX: 00007f537d28c819 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f537d507da0 R08: 00007f537d506128 R09: 0000000000000000 R10: 00000000005f10f4 R11: 0000000000000246 R12: 00000000000a49c5 R13: 00007f537d50609c R14: 00000000000a4745 R15: 00007ffd2a0443f0 Showing all locks held in the system: 3 locks held by kworker/0:1/10: 3 locks held by kworker/u8:0/12: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90000117c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90000117c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f15cfb8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 6 locks held by ktimers/0/16: 1 lock held by khungtaskd/38: #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:2/43: 2 locks held by kworker/u8:9/1404: #0: ffff88801eace938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801eace938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90005c87c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90005c87c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 4 locks held by kworker/u8:10/2986: #0: ffff88801aee1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801aee1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc9000d77fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc9000d77fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f14e800 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675 #3: ffff88803692d160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #3: ffff88803692d160 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff88803692d160 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x11b/0x3f0 net/devlink/core.c:504 3 locks held by kworker/u8:15/3137: 2 locks held by jbd2/sda1-8/5130: 1 lock held by udevd/5168: #0: ffff888019c4f2c0 (&root->kernfs_iattr_rwsem){++++}-{4:4}, at: kernfs_iop_permission+0x7f/0x430 fs/kernfs/inode.c:289 2 locks held by dhcpcd/5464: #0: ffff8880284ce928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404 #1: ffffffff8f15cfb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f15cfb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6848 2 locks held by getty/5558: #0: ffff8880370f60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by kworker/u8:12/13640: #0: ffff88801eace938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801eace938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90005627c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90005627c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 5 locks held by kworker/u8:13/13641: 3 locks held by kworker/u8:16/13648: #0: ffff888030387138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888030387138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90005717c40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90005717c40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f15cfb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f15cfb8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4738 3 locks held by syz.7.6728/21593: #0: ffff88803748fd28 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1261 #1: ffff888051cfa480 (sb_writers#21){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #1: ffff888051cfa480 (sb_writers#21){.+.+}-{0:0}, at: vfs_writev+0x2b0/0x9a0 fs/read_write.c:1057 #2: ffff888061f889b8 (&sb->s_type->i_mutex_key#30){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #2: ffff888061f889b8 (&sb->s_type->i_mutex_key#30){+.+.}-{4:4}, at: fuse_fsync+0x114/0x310 fs/fuse/file.c:540 3 locks held by syz.3.6737/21632: #0: ffff88802cc56728 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1261 #1: ffff8880753e0480 (sb_writers#21){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #1: ffff8880753e0480 (sb_writers#21){.+.+}-{0:0}, at: vfs_writev+0x2b0/0x9a0 fs/read_write.c:1057 #2: ffff8880537c53f8 (&sb->s_type->i_mutex_key#30){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #2: ffff8880537c53f8 (&sb->s_type->i_mutex_key#30){+.+.}-{4:4}, at: fuse_fsync+0x114/0x310 fs/fuse/file.c:540 7 locks held by kworker/1:2/21670: #0: ffff888021edd538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888021edd538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc900059f7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc900059f7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffff888029be8210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #2: ffff888029be8210 (&dev->mutex){....}-{4:4}, at: hub_event+0x17c/0x4f60 drivers/usb/core/hub.c:5899 #3: ffff888025972210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #3: ffff888025972210 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xde/0x970 drivers/usb/core/hub.c:2336 #4: ffff8880359231d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #4: ffff8880359231d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1166 [inline] #4: ffff8880359231d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870 drivers/base/dd.c:1364 #5: ffff88807e9a1a98 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #5: ffff88807e9a1a98 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1166 [inline] #5: ffff88807e9a1a98 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870 drivers/base/dd.c:1364 #6: ffffffff8ebc79b8 (input_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #6: ffffffff8ebc79b8 (input_mutex){+.+.}-{4:4}, at: __input_unregister_device+0x328/0x640 drivers/input/input.c:2187 9 locks held by syz-executor/22237: 2 locks held by syz.8.6915/22554: 1 lock held by syz.1.6921/22575: #0: ffff888063b3a480 (sb_writers#21){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 3 locks held by syz.1.6921/22580: #0: ffff88803d905d28 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1261 #1: ffff888063b3a480 (sb_writers#21){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #1: ffff888063b3a480 (sb_writers#21){.+.+}-{0:0}, at: vfs_writev+0x2b0/0x9a0 fs/read_write.c:1057 #2: ffff8880537c4378 (&sb->s_type->i_mutex_key#30){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #2: ffff8880537c4378 (&sb->s_type->i_mutex_key#30){+.+.}-{4:4}, at: fuse_cache_write_iter fs/fuse/file.c:1494 [inline] #2: ffff8880537c4378 (&sb->s_type->i_mutex_key#30){+.+.}-{4:4}, at: fuse_file_write_iter+0xaef/0x1130 fs/fuse/file.c:1849 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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: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+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 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: 22581 Comm: syz.0.6920 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:write_comp_data kernel/kcov.c:246 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x2a/0xa0 kernel/kcov.c:314 Code: f3 0f 1e fa 48 8b 04 24 65 48 8b 0d d8 24 8a 10 65 44 8b 05 f8 24 8a 10 41 81 e0 00 00 ff 00 ba 00 01 00 00 23 91 a4 0b 00 00 <41> 89 d1 45 09 c1 74 12 45 85 c0 75 5f 85 d2 74 5b 83 b9 74 16 00 RSP: 0018:ffffc90005ccfa00 EFLAGS: 00000246 RAX: ffffffff81b88ab1 RBX: 0000000000000000 RCX: ffff8880366a3d00 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: 0000000080000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1ed4e37 R12: 1ffff92000b99f51 R13: 0000000000000000 R14: ffffc90005ccfa88 R15: dffffc0000000000 FS: 00007feb16a566c0(0000) GS:ffff888126335000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000023000 CR3: 00000000652a8000 CR4: 00000000003526f0 Call Trace: should_resched arch/x86/include/asm/preempt.h:104 [inline] smp_call_function_single_async+0xa1/0x110 kernel/smp.c:735 rdmsr_safe_on_cpu+0x165/0x2b0 arch/x86/lib/msr-smp.c:179 msr_read+0x153/0x260 arch/x86/kernel/msr.c:66 vfs_read+0x212/0xa80 fs/read_write.c:572 ksys_read+0x156/0x270 fs/read_write.c:717 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7feb187fc819 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007feb16a56028 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007feb18a75fa0 RCX: 00007feb187fc819 RDX: 0000000000018ff0 RSI: 000020000001a400 RDI: 0000000000000003 RBP: 00007feb18892c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007feb18a76038 R14: 00007feb18a75fa0 R15: 00007ffeda0a6e28