INFO: task syz.4.1943:13380 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1943 state:D stack:27624 pid:13380 tgid:13372 ppid:12414 task_flags:0x400040 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 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 sync_bdevs+0x1ac/0x340 block/bdev.c:1288 ksys_sync+0xb9/0x150 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 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: 0033:0x7fdbfc18efc9 RSP: 002b:00007fdbfd038038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007fdbfc3e6090 RCX: 00007fdbfc18efc9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fdbfc3e6090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdbfc3e6128 R14: 00007fdbfc3e6090 R15: 00007fffd6021648 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 2 locks held by getty/5582: #0: ffff88814dba50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036c32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by udevd/6033: #0: ffff888024d08358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 1 lock held by syz.4.1943/13380: #0: ffff888024d08358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288 2 locks held by syz.0.2520/15527: #0: ffffffff8f4de3c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8f4de3c8 (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.5.2525/15551: #0: ffff888024d08358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288 2 locks held by syz.9.2532/15594: #0: ffffffff8f9ff890 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8f9ff890 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8f9ff890 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f4de3c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f4de3c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f4de3c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 2 locks held by syz.8.2540/15615: 2 locks held by syz.7.2542/15638: #0: ffffffff8dff9228 (sched_core_mutex){+.+.}-{4:4}, at: sched_core_get+0x52/0x170 kernel/sched/core.c:484 #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 ============================================= NMI backtrace for cpu 0 CPU: 0 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:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 15615 Comm: syz.8.2540 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:__lock_release kernel/locking/lockdep.c:5514 [inline] RIP: 0010:lock_release+0xc3/0x3e0 kernel/locking/lockdep.c:5889 Code: 02 00 00 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 48 8b 5c 24 20 fa 48 c7 c7 c7 c2 7f 8d e8 c4 f8 ae 09 65 ff 05 cd cc f3 10 44 24 20 01 00 00 00 83 3d de 86 00 0e 00 0f 84 96 01 00 00 41 RSP: 0018:ffffc90000a08cf8 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000006 RCX: 5c0bf5eb3c1e5b00 RDX: 0000000000000000 RSI: ffffffff8d7fc2c7 RDI: ffffffff8bc073e0 RBP: ffffc90000a08e18 R08: 0000000000000000 R09: ffffffff81ae9c97 R10: dffffc0000000000 R11: fffff520001411b0 R12: dffffc0000000000 R13: ffffffff81ae9c97 R14: ffffffff99a0b3c8 R15: ffff88802e61dac0 FS: 00007feeafb836c0(0000) GS:ffff888125e0d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055556b0485c8 CR3: 00000000673ff000 CR4: 0000000000350ef0 Call Trace: seqcount_lockdep_reader_access+0xde/0x1c0 include/linux/seqlock.h:73 ktime_get_update_offsets_now+0x67/0x3d0 kernel/time/timekeeping.c:2556 hrtimer_update_base kernel/time/hrtimer.c:633 [inline] hrtimer_interrupt+0x132/0xaa0 kernel/time/hrtimer.c:1885 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2034 [inline] RIP: 0010:vprintk_emit+0x49d/0x590 kernel/printk/printk.c:2422 Code: 0f 84 34 ff ff ff e8 92 ed 1f 00 fb eb 44 e8 8a ed 1f 00 e8 a5 2b ac 09 4d 85 f6 74 94 e8 7b ed 1f 00 fb 48 c7 c7 c0 12 13 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 1b 3b RSP: 0018:ffffc9000d737660 EFLAGS: 00000287 RAX: ffffffff81a05675 RBX: ffffffff81a054ce RCX: 0000000000080000 RDX: ffffc9000c199000 RSI: 000000000003824c RDI: ffffffff8e1312c0 RBP: ffffc9000d737770 R08: ffffffff8f9dfa77 R09: 1ffffffff1f3bf4e R10: dffffc0000000000 R11: fffffbfff1f3bf4f R12: 0000000000000000 R13: 000000000000001f R14: 0000000000000200 R15: 1ffff92001ae6ed0 _printk+0xcf/0x120 kernel/printk/printk.c:2448 __xfs_printk fs/xfs/xfs_message.c:24 [inline] xfs_printk_level+0x18b/0x280 fs/xfs/xfs_message.c:44 xfs_log_mount_finish+0x28e/0x3b0 fs/xfs/xfs_log.c:767 xfs_mountfs+0x18b6/0x22c0 fs/xfs/xfs_mount.c:1155 xfs_fs_fill_super+0x11b3/0x1600 fs/xfs/xfs_super.c:1926 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691 vfs_get_tree+0x92/0x2b0 fs/super.c:1751 fc_mount fs/namespace.c:1208 [inline] do_new_mount_fc fs/namespace.c:3651 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3727 do_mount fs/namespace.c:4050 [inline] __do_sys_mount fs/namespace.c:4238 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4215 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: 0033:0x7feeaed9076a Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007feeafb82e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007feeafb82ef0 RCX: 00007feeaed9076a RDX: 0000200000000800 RSI: 0000200000000080 RDI: 00007feeafb82eb0 RBP: 0000200000000800 R08: 00007feeafb82ef0 R09: 0000000002000048 R10: 0000000002000048 R11: 0000000000000246 R12: 0000200000000080 R13: 00007feeafb82eb0 R14: 000000000000b950 R15: 0000200000000000