INFO: task syz.8.832:9409 blocked for more than 143 seconds. Not tainted 6.15.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.832 state:D stack:27000 pid:9409 tgid:9408 ppid:8467 task_flags:0x400040 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 ___down_common kernel/locking/semaphore.c:229 [inline] __down_common+0x319/0x6a0 kernel/locking/semaphore.c:250 down+0x80/0xd0 kernel/locking/semaphore.c:64 console_lock+0x145/0x1b0 kernel/printk/printk.c:2849 vcs_open+0x5d/0xd0 drivers/tty/vt/vc_screen.c:763 chrdev_open+0x4c9/0x5e0 fs/char_dev.c:414 do_dentry_open+0xdf0/0x1970 fs/open.c:956 vfs_open+0x3b/0x340 fs/open.c:1086 do_open fs/namei.c:3880 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4039 do_filp_open+0x1fa/0x410 fs/namei.c:4066 do_sys_openat2+0x121/0x1c0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1455 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f47b618e969 RSP: 002b:00007f47b70e2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f47b63b5fa0 RCX: 00007f47b618e969 RDX: 0000000000000100 RSI: 0000200000000280 RDI: ffffffffffffff9c RBP: 00007f47b6210ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f47b63b5fa0 R15: 00007f47b64dfa28 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3d860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3d860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3d860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 2 locks held by kworker/1:1/47: #0: ffff88801a080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90000b87c60 (console_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000b87c60 (console_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 2 locks held by getty/5588: #0: ffff8880303a30a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222 6 locks held by syz.1.570/8189: 1 lock held by syz.0.582/8222: 2 locks held by syz.0.1259/11867: #0: ffffffff8e78b488 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline] #0: ffffffff8e78b488 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x200/0xd10 drivers/tty/tty_io.c:2129 #1: ffff888048dce1c0 (&tty->legacy_mutex){+.+.}-{4:4}, at: tty_init_dev+0x74/0x4d0 drivers/tty/tty_io.c:1415 1 lock held by syz.4.1270/11917: #0: ffffffff8e78b488 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline] #0: ffffffff8e78b488 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x200/0xd10 drivers/tty/tty_io.c:2129 1 lock held by syz.5.1284/12067: #0: ffffffff8e78b488 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0xdc/0x2e0 drivers/tty/pty.c:823 7 locks held by syz-executor/12079: 1 lock held by syz.9.1291/12128: 3 locks held by syz-executor/12138: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc6-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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: 12138 Comm: syz-executor Not tainted 6.15.0-rc6-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:write_comp_data kernel/kcov.c:246 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x18/0x90 kernel/kcov.c:314 Code: 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 14 25 08 70 75 92 65 8b 0d 68 9c b5 10 <81> e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75 5b 83 ba 3c 16 00 00 RSP: 0018:ffffc90002eaf4f0 EFLAGS: 00000246 RAX: ffffffff825b3c79 RBX: 0000000000000001 RCX: 0000000080000000 RDX: ffff888042043c00 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff8880569c1148 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff825b0eac R12: ffff88808842d130 R13: ffff8880569c1128 R14: 0000000011458a0a R15: ffffffff8c715040 FS: 000055557ba77500(0000) GS:ffff8881261c9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4eadf10850 CR3: 000000008b1be000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000c DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: kernfs_rcu_name fs/kernfs/kernfs-internal.h:112 [inline] kernfs_sd_compare fs/kernfs/dir.c:349 [inline] kernfs_link_sibling+0xd9/0x3e0 fs/kernfs/dir.c:380 kernfs_add_one+0x1e0/0x520 fs/kernfs/dir.c:810 __kernfs_create_file+0x22b/0x2e0 fs/kernfs/file.c:1067 sysfs_add_file_mode_ns+0x238/0x300 fs/sysfs/file.c:319 create_files fs/sysfs/group.c:76 [inline] internal_create_group+0x66d/0x1110 fs/sysfs/group.c:183 internal_create_groups fs/sysfs/group.c:223 [inline] sysfs_create_groups+0x59/0x120 fs/sysfs/group.c:249 device_add_groups drivers/base/core.c:2839 [inline] device_add_attrs+0x1c4/0x5a0 drivers/base/core.c:2914 device_add+0x496/0xb50 drivers/base/core.c:3646 netdev_register_kobject+0x156/0x2f0 net/core/net-sysfs.c:2336 register_netdevice+0x126c/0x1af0 net/core/dev.c:10997 register_netdev+0x40/0x60 net/core/dev.c:11114 ip6gre_init_net+0x27d/0x3b0 net/ipv6/ip6_gre.c:1629 ops_init+0x359/0x5c0 net/core/net_namespace.c:138 setup_net+0x238/0x830 net/core/net_namespace.c:364 copy_net_ns+0x32e/0x590 net/core/net_namespace.c:518 create_new_namespaces+0x3d3/0x700 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11c/0x170 kernel/nsproxy.c:228 ksys_unshare+0x4c8/0x8c0 kernel/fork.c:3375 __do_sys_unshare kernel/fork.c:3446 [inline] __se_sys_unshare kernel/fork.c:3444 [inline] __x64_sys_unshare+0x38/0x50 kernel/fork.c:3444 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1a76990167 Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 10 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1a76cdffa8 EFLAGS: 00000206 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f1a76a123d9 RCX: 00007f1a76990167 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 0000000000000000 R08: 00007f1a776e7d60 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000