INFO: task syz-executor:293 blocked for more than 122 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:0 pid:293 tgid:293 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:6054 [inline] __schedule+0x1496/0x20b0 kernel/sched/core.c:7867 __schedule_loop kernel/sched/core.c:7944 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7959 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8016 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x902/0x1b90 kernel/locking/mutex.c:806 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285 rcu_barrier+0x4d/0x580 kernel/rcu/tree.c:4589 netdev_run_todo+0x118/0xce0 net/core/dev.c:10912 rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152 tun_detach drivers/net/tun.c:704 [inline] tun_chr_close+0xc5/0x150 drivers/net/tun.c:3520 __fput+0x20b/0xa30 fs/file_table.c:447 ____fput+0x20/0x30 fs/file_table.c:475 task_work_run+0x1e8/0x260 kernel/task_work.c:246 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0xa46/0x2850 kernel/exit.c:955 do_group_exit+0x21f/0x2f0 kernel/exit.c:1098 get_signal+0x134c/0x1490 kernel/signal.c:2933 arch_do_signal_or_restart+0xbc/0x700 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x57/0xb0 kernel/entry/common.c:218 do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f4f5af58fd7 RSP: 002b:00007ffda8948260 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000555591abd500 RCX: 00007f4f5af58fd7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007ffda89482ec R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000004e R13: 0000000000000057 R14: 000000000001e335 R15: 00007ffda8948340 INFO: task syz.2.143:782 blocked for more than 126 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.143 state:D stack:0 pid:782 tgid:782 ppid:299 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:6054 [inline] __schedule+0x1496/0x20b0 kernel/sched/core.c:7867 __schedule_loop kernel/sched/core.c:7944 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7959 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8016 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x902/0x1b90 kernel/locking/mutex.c:806 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285 rcu_barrier+0x4d/0x580 kernel/rcu/tree.c:4589 netdev_run_todo+0x118/0xce0 net/core/dev.c:10912 rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152 tun_detach drivers/net/tun.c:704 [inline] tun_chr_close+0xc5/0x150 drivers/net/tun.c:3520 __fput+0x20b/0xa30 fs/file_table.c:447 ____fput+0x20/0x30 fs/file_table.c:475 task_work_run+0x1e8/0x260 kernel/task_work.c:246 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0xa46/0x2850 kernel/exit.c:955 do_group_exit+0x21f/0x2f0 kernel/exit.c:1098 get_signal+0x134c/0x1490 kernel/signal.c:2933 arch_do_signal_or_restart+0xbc/0x700 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x57/0xb0 kernel/entry/common.c:218 do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: ffff:0x11 RSP: 002b:0000000000000000 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 7d836c68f7d55d9b8be32a3afed0c3f02dc2df9e Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120 dump_stack+0x19/0x20 lib/dump_stack.c:129 nmi_cpu_backtrace+0x2ba/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline] watchdog+0xe45/0xf90 kernel/hung_task.c:423 kthread+0x2c7/0x360 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 285 Comm: sshd-session Not tainted syzkaller #0 7d836c68f7d55d9b8be32a3afed0c3f02dc2df9e Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:update_stack_state+0x426/0x4d0 arch/x86/kernel/unwind_frame.c:257 Code: 8b 5d d0 48 83 c3 48 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 d7 8a 9b 00 4c 89 33 43 80 7c 3d 00 00 48 8b 5d c0 <74> 08 48 89 df e8 a0 89 9b 00 b0 01 48 83 3b 00 0f 85 62 fe ff ff RSP: 0018:ffffc900011ef5a8 EFLAGS: 00000246 RAX: 1ffff9200023dee2 RBX: ffffc900011ef708 RCX: ffffc900011efc01 RDX: ffffc900011efc68 RSI: 1ffff9200023deda RDI: ffffc900011ef6f0 RBP: ffffc900011ef658 R08: ffffc900011ef790 R09: ffffc900011ef788 R10: 0000000000000007 R11: ffffffff81759d20 R12: ffffc900011ef720 R13: 1ffff9200023dee1 R14: ffffffff81e035b5 R15: dffffc0000000000 FS: 00007fae75546300(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fae74ff84c0 CR3: 0000000108692000 CR4: 00000000003526b0 Call Trace: unwind_next_frame+0x39e/0x6b0 arch/x86/kernel/unwind_frame.c:315 arch_stack_walk+0x138/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 save_stack+0x125/0x240 mm/page_owner.c:174 __reset_page_owner+0x79/0x450 mm/page_owner.c:315 reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1390 [inline] free_unref_page+0xbb8/0xf70 mm/page_alloc.c:2876 __free_pages+0x6b/0x3b0 mm/page_alloc.c:5402 __free_slab+0xb2/0x110 mm/slub.c:2758 free_slab+0x18/0xe0 mm/slub.c:2781 discard_slab mm/slub.c:2787 [inline] __put_partials+0x115/0x150 mm/slub.c:3256 put_cpu_partial+0x91/0xc0 mm/slub.c:3331 __slab_free+0x1cf/0x2a0 mm/slub.c:4584 do_slab_free mm/slub.c:4666 [inline] ___cache_free+0xc9/0xe0 mm/slub.c:4781 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0xb5/0x130 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x180 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x28/0x90 mm/kasan/common.c:331 kasan_slab_alloc include/linux/kasan.h:251 [inline] slab_post_alloc_hook mm/slub.c:4202 [inline] slab_alloc_node mm/slub.c:4251 [inline] kmem_cache_alloc_lru_noprof+0x1c2/0x410 mm/slub.c:4272 sock_alloc_inode+0x48/0x150 net/socket.c:308 alloc_inode+0x7d/0x270 fs/inode.c:269 new_inode_pseudo+0x19/0x40 fs/inode.c:1117 sock_alloc net/socket.c:634 [inline] __sock_create+0x130/0x810 net/socket.c:1540 sock_create net/socket.c:1634 [inline] __sys_socket_create net/socket.c:1671 [inline] __sys_socket+0xe1/0x1c0 net/socket.c:1718 __do_sys_socket net/socket.c:1732 [inline] __se_sys_socket net/socket.c:1730 [inline] __x64_sys_socket+0x7e/0x90 net/socket.c:1730 x64_sys_call+0x2608/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:42 do_syscall_x64 arch/x86/entry/common.c:47 [inline] do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fae74f22707 Code: 54 24 0c e8 6b ac ff ff 83 f8 ff 74 04 8b 44 24 0c 48 83 c4 18 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 b8 29 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d c1 e6 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd41ec4638 EFLAGS: 00000202 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 0000000000000026 RCX: 00007fae74f22707 RDX: 0000000000000000 RSI: 0000000000080002 RDI: 0000000000000001 RBP: 00007fae74fae560 R08: 00000000000001f4 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002 R13: 00007ffd41ec4760 R14: 0000000000000049 R15: 00007ffd41ec4760