INFO: task syz.2.663:9665 blocked for more than 143 seconds. Not tainted 6.16.0-rc2-syzkaller-00269-g11313e2f7812 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.663 state:D stack:26520 pid:9665 tgid:9664 ppid:5824 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6878 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747 bdev_open+0x41a/0xe40 block/bdev.c:945 bdev_file_open_by_dev block/bdev.c:1059 [inline] bdev_file_open_by_dev+0x182/0x210 block/bdev.c:1034 bdev_file_open_by_path+0xed/0x330 block/bdev.c:1082 btrfs_scan_one_device+0xcf/0x680 fs/btrfs/volumes.c:1464 btrfs_get_tree_super fs/btrfs/super.c:1842 [inline] btrfs_get_tree+0x3e8/0x1b70 fs/btrfs/super.c:2088 vfs_get_tree+0x8b/0x340 fs/super.c:1804 fc_mount+0x18/0x110 fs/namespace.c:1290 btrfs_get_tree_subvol fs/btrfs/super.c:2046 [inline] btrfs_get_tree+0xa37/0x1b70 fs/btrfs/super.c:2089 vfs_get_tree+0x8b/0x340 fs/super.c:1804 do_new_mount fs/namespace.c:3885 [inline] path_mount+0x1414/0x2020 fs/namespace.c:4209 do_mount fs/namespace.c:4222 [inline] __do_sys_mount fs/namespace.c:4433 [inline] __se_sys_mount fs/namespace.c:4410 [inline] __x64_sys_mount+0x28d/0x310 fs/namespace.c:4410 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f36fef8e929 RSP: 002b:00007f36ffd1a038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f36ff1b5fa0 RCX: 00007f36fef8e929 RDX: 0000200000000200 RSI: 0000200000000300 RDI: 0000200000000280 RBP: 00007f36ff010b39 R08: 0000200000000380 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f36ff1b5fa0 R15: 00007ffeb0392ae8 Showing all locks held in the system: 2 locks held by kworker/1:0/24: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc900001e7d10 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 1 lock held by khungtaskd/31: #0: ffffffff8e5c4880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c4880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c4880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 2 locks held by getty/5573: #0: ffff8880326df0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by kworker/u8:9/5994: #0: ffff888032107148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000213fd10 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff9034d1a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff9034d1a8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x120/0x14e0 net/ipv6/addrconf.c:4198 1 lock held by udevd/6241: #0: ffff888026b83358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 2 locks held by syz.2.663/9665: #0: ffffffff8edd1e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree_super fs/btrfs/super.c:1836 [inline] #0: ffffffff8edd1e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x3b3/0x1b70 fs/btrfs/super.c:2088 #1: ffff888026b83358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 1 lock held by syz.1.901/11994: #0: ffff888026b83358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0xfd/0x360 block/bdev.c:1288 1 lock held by syz-executor/12436: 8 locks held by syz-executor/12495: #0: ffff88802500c428 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738 #1: ffff88802a0aac88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x510 fs/kernfs/file.c:325 #2: ffff8881443055a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2b2/0x510 fs/kernfs/file.c:326 #3: ffffffff8f8e9ee8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x4a0 drivers/net/netdevsim/bus.c:216 #4: ffff88806a97b0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #4: ffff88806a97b0e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #4: ffff88806a97b0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1292 #5: ffff88806a97e250 (&devlink->lock_key#50){+.+.}-{4:4}, at: nsim_drv_remove+0x4a/0x1d0 drivers/net/netdevsim/dev.c:1675 #6: ffffffff9034d1a8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xfc/0x5d0 drivers/net/netdevsim/netdev.c:1064 #7: ffffffff8e5cfe78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336 1 lock held by syz.5.952/12678: #0: ffffffff9034d1a8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff9034d1a8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3396 1 lock held by cmp/12699: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc2-syzkaller-00269-g11313e2f7812 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 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: 12677 Comm: syz.6.953 Not tainted 6.16.0-rc2-syzkaller-00269-g11313e2f7812 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:stack_trace_consume_entry+0xd7/0x170 kernel/stacktrace.c:93 Code: 02 00 0f 85 9a 00 00 00 8d 45 01 89 43 10 48 8b 03 48 8d 2c e8 48 b8 00 00 00 00 00 fc ff df 48 89 ea 48 c1 ea 03 80 3c 02 00 <75> 64 48 89 75 00 8b 43 08 39 43 10 0f 92 c0 48 83 c4 08 5b 5d c3 RSP: 0018:ffffc90003f4f6f8 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffffc90003f4f7d8 RCX: ffffc90003f4f66c RDX: 1ffff920007e9f10 RSI: ffffffff82351bef RDI: ffffc90003f4f7e4 RBP: ffffc90003f4f880 R08: ffffffff9143ce4e R09: 0000000000000000 R10: 0000000000000000 R11: 000000000000bc1c R12: ffffffff81a77fd0 R13: ffffc90003f4f7d8 R14: 0000000000000000 R15: ffff88802ebd2440 FS: 0000000000000000(0000) GS:ffff888124753000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563ece92a300 CR3: 00000000317e4000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x88/0x100 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706 vfree+0x1fd/0xb50 mm/vmalloc.c:3426 kcov_put kernel/kcov.c:439 [inline] kcov_put kernel/kcov.c:435 [inline] kcov_close+0x34/0x60 kernel/kcov.c:535 __fput+0x3ff/0xb70 fs/file_table.c:465 task_work_run+0x150/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x864/0x2bd0 kernel/exit.c:955 do_group_exit+0xd3/0x2a0 kernel/exit.c:1104 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faa5698e929 Code: Unable to access opcode bytes at 0x7faa5698e8ff. RSP: 002b:00007faa547f6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: 00000000000000b0 RBX: 00007faa56bb5fa0 RCX: 00007faa5698e929 RDX: 0000000000000000 RSI: 0000200000000080 RDI: 0000000000000003 RBP: 00007faa56a10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007faa56bb5fa0 R15: 00007ffcc06893b8