INFO: task syz.0.17:6094 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:26088 pid:6094 tgid:6094 ppid:6018 task_flags:0x400640 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x3da/0x710 kernel/sched/completion.c:121 wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:269 coredump_wait fs/coredump.c:534 [inline] vfs_coredump+0x8cf/0x2a60 fs/coredump.c:1131 get_signal+0x1108/0x1340 kernel/signal.c:3019 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:40 [inline] exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] irqentry_exit_to_user_mode+0x7e/0x110 kernel/entry/common.c:73 exc_page_fault+0xab/0x100 arch/x86/mm/fault.c:1535 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f94f6c4f987 RSP: 002b:00007fffa08bc2e0 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00000000000280a0 RDX: 00007fffa08bc300 RSI: 00007fffa08bc430 RDI: 000000000000000b RBP: 00007f94f6fd7da0 R08: 0000000023074391 R09: 7fffffffffffffff R10: 3fffffffffffffff R11: 0000000000000000 R12: 00000000000285f5 R13: 00007f94f6fd6090 R14: ffffffffffffffff R15: 00007fffa09bb100 INFO: task syz.1.18:6157 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.18 state:D stack:26944 pid:6157 tgid:6157 ppid:6138 task_flags:0x400640 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x3da/0x710 kernel/sched/completion.c:121 wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:269 coredump_wait fs/coredump.c:534 [inline] vfs_coredump+0x8cf/0x2a60 fs/coredump.c:1131 get_signal+0x1108/0x1340 kernel/signal.c:3019 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:40 [inline] exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] irqentry_exit_to_user_mode+0x7e/0x110 kernel/entry/common.c:73 exc_page_fault+0xab/0x100 arch/x86/mm/fault.c:1535 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7ff86524f987 RSP: 002b:00007ffdf9635360 EFLAGS: 00010206 RAX: 0000000000000000 RBX: 000000000000000b RCX: 000000000002c308 RDX: 00007ffdf9635380 RSI: 00007ffdf96354b0 RDI: 000000000000000b RBP: 00007ff8655d7da0 R08: 0000000008792cc5 R09: 7fffffffffffffff R10: 3fffffffffffffff R11: 0000000000000000 R12: 000000000002c6a0 R13: 00007ff8655d6090 R14: ffffffffffffffff R15: 00007ffdf9732a50 Showing all locks held in the system: 5 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/31: #0: ffffffff8e53d260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e53d260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e53d260 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5622: #0: ffff888034ef70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000331e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 ============================================= 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 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: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: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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 33 8a 1a 00 f3 0f 1e fa fb f4 c8 e6 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6 RAX: 4d601e46a9e4a900 RBX: ffffffff8196e2b7 RCX: 4d601e46a9e4a900 RDX: 0000000000000001 RSI: ffffffff8dc89575 RDI: ffffffff8c053d60 RBP: ffffc90000197f10 R08: ffff8880b8732fdb R09: 1ffff110170e65fb R10: dffffc0000000000 R11: ffffed10170e65fc R12: ffffffff8fe4db70 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003adab58 FS: 0000000000000000(0000) GS:ffff8881258a2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055946e818ed0 CR3: 000000000e338000 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:190 [inline] do_idle+0x1e7/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147