INFO: task syz.3.1902:12733 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.3.1902 state:D stack:25784 pid:12733 tgid:12733 ppid:5847 task_flags:0x40004c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 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:312 [inline] exit_mmap+0x281/0xb20 mm/mmap.c:1288 __mmput+0x118/0x430 kernel/fork.c:1130 exit_mm+0x1da/0x2c0 kernel/exit.c:583 do_exit+0x658/0x2310 kernel/exit.c:961 do_group_exit+0x21c/0x2d0 kernel/exit.c:1114 __do_sys_exit_group kernel/exit.c:1125 [inline] __se_sys_exit_group kernel/exit.c:1123 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1123 x64_sys_call+0x2210/0x2210 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd073f8f749 RSP: 002b:00007fffb53a2578 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd073f8f749 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fffb53a25dc R08: 0000001eb53a266f R09: 00000000000927c0 R10: 0000000000000210 R11: 0000000000000246 R12: 0000000000000175 R13: 00000000000927c0 R14: 00000000000317e8 R15: 00007fffb53a2630 INFO: task syz.2.1912:12765 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.2.1912 state:D stack:26680 pid:12765 tgid:12762 ppid:5838 task_flags:0x40054c flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 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:312 [inline] exit_mmap+0x281/0xb20 mm/mmap.c:1288 __mmput+0x118/0x430 kernel/fork.c:1130 exit_mm+0x1da/0x2c0 kernel/exit.c:583 do_exit+0x658/0x2310 kernel/exit.c:961 do_group_exit+0x21c/0x2d0 kernel/exit.c:1114 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+0x87/0x4f0 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+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdf9858f749 RSP: 002b:00007fdf9938f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffed RBX: 00007fdf987e6180 RCX: 00007fdf9858f749 RDX: 00002000000007c0 RSI: 0000000000008933 RDI: 000000000000000c RBP: 00007fdf98613f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdf987e6218 R14: 00007fdf987e6180 R15: 00007ffd906c9518 INFO: task syz.1.1915:12766 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.1.1915 state:D stack:26680 pid:12766 tgid:12766 ppid:5833 task_flags:0x40044c flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 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:312 [inline] exit_mmap+0x281/0xb20 mm/mmap.c:1288 __mmput+0x118/0x430 kernel/fork.c:1130 exit_mm+0x1da/0x2c0 kernel/exit.c:583 do_exit+0x658/0x2310 kernel/exit.c:961 do_group_exit+0x21c/0x2d0 kernel/exit.c:1114 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+0x87/0x4f0 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+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f209a18f783 RSP: 002b:00007ffd189a4668 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: fffffffffffffffc RBX: 0000001b31164000 RCX: 00007f209a18f783 RDX: 0000000000000003 RSI: 00000000003c0000 RDI: 0000001b31164000 RBP: 0000000000400000 R08: 0000000000000004 R09: 0000000000040000 R10: 0000000000100001 R11: 0000000000000246 R12: 00000000000001a4 R13: 00000000000927c0 R14: 0000000000031a8b R15: 00007ffd189a4950 INFO: task syz.0.1913:12768 blocked for more than 144 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1913 state:D stack:26648 pid:12768 tgid:12768 ppid:5843 task_flags:0x40044c flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 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:312 [inline] exit_mmap+0x281/0xb20 mm/mmap.c:1288 __mmput+0x118/0x430 kernel/fork.c:1130 exit_mm+0x1da/0x2c0 kernel/exit.c:583 do_exit+0x658/0x2310 kernel/exit.c:961 do_group_exit+0x21c/0x2d0 kernel/exit.c:1114 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+0x87/0x4f0 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+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f44c2d8f783 RSP: 002b:00007ffc7b8fd8f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: fffffffffffffffc RBX: 00007f44c17f76c0 RCX: 00007f44c2d8f783 RDX: 0000000000000000 RSI: 0000000000021000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000020022 R11: 0000000000000246 R12: 00007ffc7b8fda50 R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000 INFO: task syz.4.1914:12769 blocked for more than 144 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1914 state:D stack:25272 pid:12769 tgid:12769 ppid:5842 task_flags:0x40044c flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 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:312 [inline] exit_mmap+0x281/0xb20 mm/mmap.c:1288 __mmput+0x118/0x430 kernel/fork.c:1130 exit_mm+0x1da/0x2c0 kernel/exit.c:583 do_exit+0x658/0x2310 kernel/exit.c:961 do_group_exit+0x21c/0x2d0 kernel/exit.c:1114 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+0x87/0x4f0 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+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc083f8f783 RSP: 002b:00007ffc7b010878 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: fffffffffffffffc RBX: 00007fc0829f76c0 RCX: 00007fc083f8f783 RDX: 0000000000000000 RSI: 0000000000021000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000020022 R11: 0000000000000246 R12: 00007ffc7b0109d0 R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df41cc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df41cc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df41cc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:2/36: #0: ffff88801a069148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88801a069148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc90000ac7b80 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90000ac7b80 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 2 locks held by kworker/u8:8/1321: #0: ffff88801a069148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88801a069148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000450fb80 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000450fb80 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 2 locks held by dhcpcd/5499: #0: ffffffff8dffdcf0 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1485 [inline] #0: ffffffff8dffdcf0 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x131/0x4b0 kernel/fork.c:1538 #1: ffff88807f146540 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:330 [inline] #1: ffff88807f146540 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x126/0x1b10 mm/mmap.c:1727 2 locks held by getty/5597: #0: ffff88814e9680a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5823: #0: ffff8880307d4080 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:330 [inline] #0: ffff8880307d4080 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x211/0x4d0 mm/util.c:579 1 lock held by syz-executor/5843: #0: ffff8880335e3440 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:312 [inline] #0: ffff8880335e3440 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x281/0xb20 mm/mmap.c:1288 1 lock held by udevd/12234: #0: ffff888024a76358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962 1 lock held by syz.3.1902/12733: #0: ffff88807f098340 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:312 [inline] #0: ffff88807f098340 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x281/0xb20 mm/mmap.c:1288 1 lock held by syz.2.1912/12765: #0: ffff8880265c5900 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:312 [inline] #0: ffff8880265c5900 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x281/0xb20 mm/mmap.c:1288 1 lock held by syz.1.1915/12766: #0: ffff88804874c080 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:312 [inline] #0: ffff88804874c080 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x281/0xb20 mm/mmap.c:1288 1 lock held by modprobe/12767: #0: ffff888048748340 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:330 [inline] #0: ffff888048748340 (&mm->mmap_lock){++++}-{4:4}, at: setup_arg_pages+0x2ab/0xa90 fs/exec.c:650 1 lock held by syz.0.1913/12768: #0: ffff8880265c6540 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:312 [inline] #0: ffff8880265c6540 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x281/0xb20 mm/mmap.c:1288 1 lock held by syz.4.1914/12769: #0: ffff888028217180 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:312 [inline] #0: ffff888028217180 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x281/0xb20 mm/mmap.c:1288 1 lock held by modprobe/12770: #0: ffff88804874f180 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:330 [inline] #0: ffff88804874f180 (&mm->mmap_lock){++++}-{4:4}, at: setup_arg_pages+0x2ab/0xa90 fs/exec.c:650 1 lock held by dhcpcd/12771: #0: ffff88804874a800 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:330 [inline] #0: ffff88804874a800 (&mm->mmap_lock){++++}-{4:4}, at: __vm_munmap+0x136/0x380 mm/vma.c:3153 ============================================= 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+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+0xf3c/0xf80 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 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: 53 ec 02 00 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 0d 1f 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6 RAX: cf900434dc24c000 RBX: ffffffff8197438a RCX: cf900434dc24c000 RDX: 0000000000000001 RSI: ffffffff8d76be8f RDI: ffffffff8bbfc660 RBP: ffffc90000197f10 R08: ffff8880b893359b R09: 1ffff110171266b3 R10: dffffc0000000000 R11: ffffed10171266b4 R12: ffffffff8f805a70 R13: 1ffff11003953b70 R14: 0000000000000001 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881261b1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b213e1d168 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+0x1ea/0x520 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