INFO: task syz.4.83:6278 blocked for more than 144 seconds. Not tainted 6.15.0-rc1-syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.83 state:D stack:26792 pid:6278 tgid:6278 ppid:5834 task_flags:0x40004c flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 rwsem_down_write_slowpath+0xedd/0x1420 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write+0x1da/0x220 kernel/locking/rwsem.c:1578 mmap_write_lock include/linux/mmap_lock.h:128 [inline] exit_mmap+0x305/0xde0 mm/mmap.c:1292 __mmput+0x115/0x420 kernel/fork.c:1379 exit_mm+0x221/0x310 kernel/exit.c:589 do_exit+0x994/0x27f0 kernel/exit.c:940 do_group_exit+0x207/0x2c0 kernel/exit.c:1102 __do_sys_exit_group kernel/exit.c:1113 [inline] __se_sys_exit_group kernel/exit.c:1111 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111 x64_sys_call+0x26c3/0x26d0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f17b238d169 RSP: 002b:00007fffd6e38fc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f17b238d169 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fffd6e3902c R08: 00000008d6e390bf R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000008 R13: 00000000000927c0 R14: 00000000000221ca R15: 00007fffd6e39080 Showing all locks held in the system: 3 locks held by kworker/0:0/9: #0: ffff88801b078d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b078d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc900000e7c60 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc900000e7c60 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8ed434f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #2: ffffffff8ed434f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x384/0x830 kernel/rcu/tree_exp.h:998 1 lock held by khungtaskd/31: #0: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6764 8 locks held by kworker/u8:9/3032: #0: ffff88801bef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801bef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000ba8fc60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000ba8fc60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff900f0850 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x17c/0xd60 net/core/net_namespace.c:608 #3: ffff88805ae760e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff88805ae760e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff88805ae760e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x13d/0x450 net/devlink/core.c:506 #4: ffff88805ae75250 (&devlink->lock_key#8){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff88805ae75250 (&devlink->lock_key#8){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff88805ae75250 (&devlink->lock_key#8){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x14f/0x450 net/devlink/core.c:506 #5: ffffffff900fd388 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x10d/0x690 drivers/net/netdevsim/netdev.c:1059 #6: ffff88803506cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #6: ffff88803506cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] #6: ffff88803506cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x5a1/0x2510 net/core/dev.c:11947 #7: ffffffff8ed434f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #7: ffffffff8ed434f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x454/0x830 kernel/rcu/tree_exp.h:998 2 locks held by getty/5596: #0: ffff88814d6140a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900033532f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x5bb/0x1700 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5833: #0: ffff8880336747e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:128 [inline] #0: ffff8880336747e0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x305/0xde0 mm/mmap.c:1292 1 lock held by syz-executor/5839: #0: ffffffff900fd388 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff900fd388 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3390 1 lock held by syz.4.83/6278: #0: ffff888024823de0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:128 [inline] #0: ffff888024823de0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x305/0xde0 mm/mmap.c:1292 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc1-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:437 kthread+0x7b9/0x940 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153 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: 6440 Comm: syz-executor Not tainted 6.15.0-rc1-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:arch_stack_walk+0x125/0x150 arch/x86/kernel/stacktrace.c:24 Code: e1 b8 09 00 48 85 c0 74 23 4c 89 f7 48 89 c6 4d 89 eb e8 ee 55 cf 0a 84 c0 74 11 48 89 df e8 12 ba 09 00 83 bd 70 ff ff ff 00 <75> d0 48 c7 c0 20 a0 68 93 65 48 8b 00 48 3b 45 d0 75 13 48 83 c4 RSP: 0018:ffffc9000e3e7540 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffc9000e3e7540 RCX: 0000000000000000 RDX: 0000000000000010 RSI: ffffffff8e4fd4cc RDI: ffffffff8ca1b620 RBP: ffffc9000e3e75d0 R08: ffffc9000e3e759f R09: ffffc9000e3e7590 R10: dffffc0000000000 R11: fffff52001c7ceb4 R12: ffff88802aa39e00 R13: ffffffff81aee970 R14: ffffc9000e3e7620 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124f96000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f24b5fa6038 CR3: 0000000035748000 CR4: 0000000000350ef0 Call Trace: stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122 save_stack+0xfc/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x1e0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1262 [inline] __free_frozen_pages+0xde8/0x10a0 mm/page_alloc.c:2680 vfree+0x1c3/0x360 mm/vmalloc.c:3383 kcov_put kernel/kcov.c:439 [inline] kcov_close+0x28/0x50 kernel/kcov.c:535 __fput+0x3eb/0x9f0 fs/file_table.c:465 task_work_run+0x253/0x310 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa11/0x27f0 kernel/exit.c:953 do_group_exit+0x207/0x2c0 kernel/exit.c:1102 get_signal+0x1696/0x1730 kernel/signal.c:3034 arch_do_signal_or_restart+0x98/0x840 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:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7facf1b8e497 Code: Unable to access opcode bytes at 0x7facf1b8e46d. RSP: 002b:00007ffcb4307738 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007facf1c0e08c RCX: 00007facf1b8e497 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcb43077f0 RBP: 00007ffcb43077f0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffcb4308880 R13: 00007facf1c0e08c R14: 0000000000046ddf R15: 00007ffcb43088c0