INFO: task syz.1.3063:16771 blocked for more than 143 seconds. Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.3063 state:D stack:25992 pid:16771 tgid:16767 ppid:15704 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5351 [inline] __schedule+0x1737/0x4d30 kernel/sched/core.c:6954 __schedule_loop kernel/sched/core.c:7036 [inline] schedule+0x165/0x360 kernel/sched/core.c:7051 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7108 rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1187 __down_write_common kernel/locking/rwsem.c:1319 [inline] __down_write kernel/locking/rwsem.c:1328 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1593 mmap_write_lock include/linux/mmap_lock.h:356 [inline] do_mbind mm/mempolicy.c:1460 [inline] kernel_mbind mm/mempolicy.c:1682 [inline] __do_sys_mbind mm/mempolicy.c:1756 [inline] __se_sys_mbind+0x613/0xc30 mm/mempolicy.c:1752 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: 0033:0x7f3365b8e9a9 RSP: 002b:00007f33669d2038 EFLAGS: 00000246 ORIG_RAX: 00000000000000ed RAX: ffffffffffffffda RBX: 00007f3365db6080 RCX: 00007f3365b8e9a9 RDX: 0000000000000004 RSI: 0000000000800000 RDI: 0000200000001000 RBP: 00007f3365c10d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3365db6080 R15: 00007ffedaf74ec8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 3 locks held by kworker/u8:9/3556: #0: ffff88801a889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801a889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000bd9fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000bd9fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8f938688 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by getty/5609: #0: ffff88814dc810a0 (&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 syz.3.2946/16431: 1 lock held by syz.1.3063/16767: #0: ffff888069588ca0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:412 [inline] #0: ffff888069588ca0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0xcc/0x2c0 kernel/exit.c:557 1 lock held by syz.1.3063/16769: 1 lock held by syz.1.3063/16771: #0: ffff888069588ca0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:356 [inline] #0: ffff888069588ca0 (&mm->mmap_lock){++++}-{4:4}, at: do_mbind mm/mempolicy.c:1460 [inline] #0: ffff888069588ca0 (&mm->mmap_lock){++++}-{4:4}, at: kernel_mbind mm/mempolicy.c:1682 [inline] #0: ffff888069588ca0 (&mm->mmap_lock){++++}-{4:4}, at: __do_sys_mbind mm/mempolicy.c:1756 [inline] #0: ffff888069588ca0 (&mm->mmap_lock){++++}-{4:4}, at: __se_sys_mbind+0x613/0xc30 mm/mempolicy.c:1752 2 locks held by syz-executor/16779: #0: ffffffff8f938688 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8f938688 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3435 #1: ffffffff8e543338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #1: ffffffff8e543338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:967 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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+0x3f9/0x770 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: 16769 Comm: syz.1.3063 Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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 5b c1 67 07 48 3b 4c 24 08 0f 85 cc 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d e9 01 cb 02 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 50 e7 92 41 RSP: 0018:ffffc90004a8f298 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 00000000ffffffff RCX: 0000000080000000 RDX: 0000000000000000 RSI: ffffffff8dc7dde5 RDI: ffffffff8c04d400 RBP: 00000000ffffffff R08: ffff8880257e9e00 R09: 0000000000000004 R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000246 R13: ffff8880257e9e00 R14: ffff888069588ca0 R15: ffffffffffffffff FS: 00007f33669f36c0(0000) GS:ffff8881257ab000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055ff0f36ff38 CR3: 000000002897c000 CR4: 00000000003526f0 DR0: 0000000060000014 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:468 [inline] lock_is_held_type+0x79/0x190 kernel/locking/lockdep.c:5942 lock_is_held include/linux/lockdep.h:249 [inline] mt_locked lib/maple_tree.c:-1 [inline] mt_slot lib/maple_tree.c:800 [inline] mas_next_slot+0x97a/0xcf0 lib/maple_tree.c:4746 mas_find+0xb0e/0xd30 lib/maple_tree.c:6062 vma_next include/linux/mm.h:864 [inline] validate_mm+0xe1/0x4b0 mm/vma.c:652 vma_link+0x366/0x450 mm/vma.c:1799 copy_vma+0x70c/0x940 mm/vma.c:1880 copy_vma_and_data mm/mremap.c:1184 [inline] move_vma+0x81f/0x1840 mm/mremap.c:1282 mremap_to+0x6d6/0x7a0 mm/mremap.c:1406 remap_move mm/mremap.c:1863 [inline] do_mremap mm/mremap.c:1906 [inline] __do_sys_mremap mm/mremap.c:1970 [inline] __se_sys_mremap+0xa0b/0xef0 mm/mremap.c:1938 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: 0033:0x7f3365b8e9a9 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:00007f33669f3038 EFLAGS: 00000246 ORIG_RAX: 0000000000000019 RAX: ffffffffffffffda RBX: 00007f3365db5fa0 RCX: 00007f3365b8e9a9 RDX: 0000000000002000 RSI: 0000000000002000 RDI: 00002000003c9000 RBP: 00007f3365c10d69 R08: 00002000001de000 R09: 0000000000000000 R10: 0000000000000007 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3365db5fa0 R15: 00007ffedaf74ec8