INFO: task syz.6.1953:13783 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.1953 state:D stack:27464 pid:13783 tgid:13774 ppid:10936 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 io_schedule+0x81/0xe0 kernel/sched/core.c:7903 folio_wait_bit_common+0x6b5/0xb90 mm/filemap.c:1317 folio_wait_writeback+0xb0/0x100 mm/page-writeback.c:3124 __filemap_fdatawait_range+0x147/0x230 mm/filemap.c:539 filemap_fdatawait_keep_errors+0x31/0xd0 mm/filemap.c:633 wait_sb_inodes fs/fs-writeback.c:2715 [inline] sync_inodes_sb+0x7a9/0xa50 fs/fs-writeback.c:2837 __iterate_supers+0x13d/0x290 fs/super.c:924 ksys_sync+0x94/0x150 fs/sync.c:102 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 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: 0033:0x7ff45c59eec9 RSP: 002b:00007ff45a399038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007ff45c7f6270 RCX: 00007ff45c59eec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ff45c7f6270 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff45c7f6308 R14: 00007ff45c7f6270 R15: 00007ffca011e3e8 Showing all locks held in the system: 4 locks held by kworker/u8:1/13: #0: ffff88801a6f4138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801a6f4138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90000127bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90000127bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecc6a20 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:658 #3: ffffffff8d9ae730 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3815 1 lock held by khungtaskd/38: #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:7/1434: 2 locks held by getty/5595: #0: ffff88823bf320a0 (&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+0x444/0x1410 drivers/tty/n_tty.c:2222 3 locks held by kworker/u8:15/6037: #0: ffff88814d1f8138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88814d1f8138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000549fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000549fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194 3 locks held by kworker/1:7/7805: #0: ffff8880199ad938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff8880199ad938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90004cdfbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90004cdfbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffff88814634c188 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #2: ffff88814634c188 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898 3 locks held by kworker/u8:14/12284: #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000520fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000520fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 3 locks held by syz.8.1824/13374: #0: ffff88804fa28488 (sb_writers#25){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3108 [inline] #0: ffff88804fa28488 (sb_writers#25){.+.+}-{0:0}, at: vfs_writev+0x28e/0x970 fs/read_write.c:1055 #1: ffff8880221d0178 (&sb->s_type->i_mutex_key#29){++++}-{4:4}, at: netfs_start_io_write+0xd8/0x100 fs/netfs/locking.c:112 #2: ffff8880221d0578 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_begin_writethrough+0x67/0x140 fs/netfs/write_issue.c:626 2 locks held by syz.6.1953/13783: #0: ffff88804fa280d0 (&type->s_umount_key#87){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88804fa280d0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88804fa28b10 (&s->s_sync_lock){+.+.}-{4:4}, at: wait_sb_inodes fs/fs-writeback.c:2654 [inline] #1: ffff88804fa28b10 (&s->s_sync_lock){+.+.}-{4:4}, at: sync_inodes_sb+0x252/0xa50 fs/fs-writeback.c:2837 3 locks held by syz-executor/14559: 2 locks held by syz-executor/14631: #0: ffffffff8f1f10d0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8f1f10d0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8f1f10d0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 1 lock held by syz.5.2207/14702: #0: ffff888024d872d0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:415 [inline] #0: ffff888024d872d0 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x214/0x4d0 mm/util.c:578 1 lock held by syz.5.2207/14703: ============================================= 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:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/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: 14703 Comm: syz.5.2207 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline] RIP: 0010:check_preemption_disabled+0x59/0x120 lib/smp_processor_id.c:19 Code: 8b 0d db 14 ff 06 48 3b 4c 24 08 0f 85 cc 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d e9 41 95 03 00 cc 48 c7 04 24 00 00 00 00 9c <8f> 04 24 f7 04 24 00 02 00 00 74 c8 65 4c 8b 3c 25 08 40 f6 91 41 RSP: 0018:ffffc90004dff588 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 00000000ffffffff RCX: 0000000080000000 RDX: 0000000000000002 RSI: ffffffff8d04e087 RDI: ffffffff8b621680 RBP: 00000000ffffffff R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff940003a63bf R12: 0000000000000246 R13: ffff888030861dc0 R14: ffffffff8d9a8d80 R15: ffff88805c7fbea0 FS: 00007fb256e3e6c0(0000) GS:ffff8881268bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d823ffc CR3: 000000003b1dc000 CR4: 00000000003526f0 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline] lock_is_held_type+0x79/0x190 kernel/locking/lockdep.c:5939 xa_entry include/linux/xarray.h:1226 [inline] xas_next_entry+0x202/0x3d0 include/linux/xarray.h:1731 next_uptodate_folio+0x32/0x5d0 mm/filemap.c:3595 filemap_map_pages+0xd15/0x1380 mm/filemap.c:3789 do_fault_around mm/memory.c:5531 [inline] do_read_fault mm/memory.c:5564 [inline] do_fault mm/memory.c:5707 [inline] do_pte_missing mm/memory.c:4234 [inline] handle_pte_fault mm/memory.c:6052 [inline] __handle_mm_fault mm/memory.c:6195 [inline] handle_mm_fault+0x227f/0x3400 mm/memory.c:6364 faultin_page mm/gup.c:1144 [inline] __get_user_pages+0x16e4/0x2b60 mm/gup.c:1446 populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1880 __mm_populate+0x24c/0x380 mm/gup.c:1983 mm_populate include/linux/mm.h:3367 [inline] vm_mmap_pgoff+0x38a/0x4d0 mm/util.c:585 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: 0033:0x7fb258bdeec9 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:00007fb256e3e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fb258e35fa0 RCX: 00007fb258bdeec9 RDX: b635773f05ebbeee RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007fb258c61f91 R08: ffffffffffffffff R09: 0000000033afe000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb258e36038 R14: 00007fb258e35fa0 R15: 00007ffc1913c8e8