INFO: task syz.7.2643:15493 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.2643 state:D stack:27032 pid:15493 tgid:15487 ppid:10623 task_flags:0x40044c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591 mmap_write_lock include/linux/mmap_lock.h:335 [inline] exit_mmap+0x27b/0xb10 mm/mmap.c:1285 __mmput+0x118/0x430 kernel/fork.c:1173 exit_mm+0x169/0x230 kernel/exit.c:581 do_exit+0x627/0x22f0 kernel/exit.c:959 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4e0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc84078f749 RSP: 002b:00007fc8415cc038 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: fffffffffffffe00 RBX: 00007fc8409e6090 RCX: 00007fc84078f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fc840813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000010008095 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc8409e6128 R14: 00007fc8409e6090 R15: 00007fff92219208 INFO: task syz.3.2658:15534 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.2658 state:D stack:26080 pid:15534 tgid:15533 ppid:5847 task_flags:0x40054c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591 mmap_write_lock include/linux/mmap_lock.h:335 [inline] exit_mmap+0x27b/0xb10 mm/mmap.c:1285 __mmput+0x118/0x430 kernel/fork.c:1173 exit_mm+0x169/0x230 kernel/exit.c:581 do_exit+0x627/0x22f0 kernel/exit.c:959 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4e0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd2dbb8f749 RSP: 002b:00007fd2dc9ce0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fd2dbde5fa8 RCX: 00007fd2dbb8f749 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fd2dbde5fa8 RBP: 00007fd2dbde5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd2dbde6038 R14: 00007ffc537fdb70 R15: 00007ffc537fdc58 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:6/1309: #0: ffff88813ff29148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff29148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc90004c3fbc0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90004c3fbc0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 5 locks held by kworker/u8:7/1964: 2 locks held by kworker/u8:11/3552: #0: ffff88813ff29148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff29148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000cd57bc0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000cd57bc0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 2 locks held by kworker/u8:14/4039: #0: ffff88813ff29148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff29148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000dd47bc0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000dd47bc0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 2 locks held by getty/5592: #0: ffff88814da270a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5820: #0: ffff888078044cc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:353 [inline] #0: ffff888078044cc0 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x211/0x4d0 mm/util.c:579 1 lock held by syz-executor/10615: #0: ffff88807f39c080 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:335 [inline] #0: ffff88807f39c080 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x27b/0xb10 mm/mmap.c:1285 2 locks held by kworker/u8:25/11532: #0: ffff88813ff29148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff29148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000dae7bc0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000dae7bc0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 1 lock held by syz.7.2643/15493: #0: ffff88804becc080 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:335 [inline] #0: ffff88804becc080 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x27b/0xb10 mm/mmap.c:1285 1 lock held by syz.3.2658/15534: #0: ffff88804becd900 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:335 [inline] #0: ffff88804becd900 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x27b/0xb10 mm/mmap.c:1285 1 lock held by syz.5.2660/15536: #0: ffff88813ff1d900 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:335 [inline] #0: ffff88813ff1d900 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x27b/0xb10 mm/mmap.c:1285 2 locks held by syz-executor/15805: #0: ffffffff8dffea30 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1528 [inline] #0: ffffffff8dffea30 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x131/0x4b0 kernel/fork.c:1581 #1: ffff888054ba4080 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:353 [inline] #1: ffff888054ba4080 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x125/0x1b80 mm/mmap.c:1726 1 lock held by syz-executor/15809: #0: ffff888021b14cc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:335 [inline] #0: ffff888021b14cc0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x27b/0xb10 mm/mmap.c:1285 1 lock held by syz.8.2812/16290: #0: ffff88801e383440 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:335 [inline] #0: ffff88801e383440 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x27b/0xb10 mm/mmap.c:1285 1 lock held by syz.2.2814/16289: #0: ffff888027ebccc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:335 [inline] #0: ffff888027ebccc0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x27b/0xb10 mm/mmap.c:1285 1 lock held by modprobe/16303: #0: ffff888078040f80 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:335 [inline] #0: ffff888078040f80 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x27b/0xb10 mm/mmap.c:1285 1 lock held by modprobe/16310: #0: ffff88807c571bc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:353 [inline] #0: ffff88807c571bc0 (&mm->mmap_lock){++++}-{4:4}, at: __do_sys_brk mm/mmap.c:125 [inline] #0: ffff88807c571bc0 (&mm->mmap_lock){++++}-{4:4}, at: __se_sys_brk+0x13d/0xb80 mm/mmap.c:115 1 lock held by modprobe/16311: #0: ffff888054ba0340 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:353 [inline] #0: ffff888054ba0340 (&mm->mmap_lock){++++}-{4:4}, at: __do_sys_brk mm/mmap.c:125 [inline] #0: ffff888054ba0340 (&mm->mmap_lock){++++}-{4:4}, at: __se_sys_brk+0x13d/0xb80 mm/mmap.c:115 1 lock held by modprobe/16314: #0: ffff88807c574080 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:353 [inline] #0: ffff88807c574080 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x211/0x4d0 mm/util.c:579 1 lock held by syz.9.2818/16316: #0: ffff888054ba0f80 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:335 [inline] #0: ffff888054ba0f80 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x27b/0xb10 mm/mmap.c:1285 1 lock held by syz.0.2819/16323: #0: ffff888054ba3440 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:335 [inline] #0: ffff888054ba3440 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x27b/0xb10 mm/mmap.c:1285 1 lock held by dhcpcd-run-hook/16322: #0: ffff88807c570340 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:335 [inline] #0: ffff88807c570340 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x27b/0xb10 mm/mmap.c:1285 ============================================= 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 10/25/2025 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:160 [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+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 53 91 0e 00 f3 0f 1e fa fb f4 08 e3 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197e20 EFLAGS: 000002c6 RAX: 00000000001c39f9 RBX: ffffffff819713ee RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d792920 RDI: ffffffff8bc08360 RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8f822a70 R13: 1ffff110038d4b70 R14: 0000000000000001 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555874f55c8 CR3: 000000000dd3a000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1be/0x4d0 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147