INFO: task syz.6.810:9951 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.810 state:D stack:27424 pid:9951 tgid:9932 ppid:6087 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5257 [inline] __schedule+0x14bc/0x5030 kernel/sched/core.c:6864 __schedule_loop kernel/sched/core.c:6946 [inline] schedule+0x165/0x360 kernel/sched/core.c:6961 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7018 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1539 inode_lock_shared include/linux/fs.h:1042 [inline] lookup_slow+0x46/0x70 fs/namei.c:1871 walk_component+0x2d2/0x400 fs/namei.c:2190 lookup_last fs/namei.c:2691 [inline] path_lookupat+0x163/0x430 fs/namei.c:2715 filename_lookup+0x212/0x570 fs/namei.c:2744 user_path_at+0x3a/0x60 fs/namei.c:3536 do_mount fs/namespace.c:4054 [inline] __do_sys_mount fs/namespace.c:4246 [inline] __se_sys_mount+0x2d4/0x410 fs/namespace.c:4223 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fef1f58f749 RSP: 002b:00007fef20471038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fef1f7e6090 RCX: 00007fef1f58f749 RDX: 0000200000000b80 RSI: 0000200000000100 RDI: 0000000000000000 RBP: 00007fef1f613f91 R08: 0000200000000180 R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fef1f7e6128 R14: 00007fef1f7e6090 R15: 00007ffd6140b068 INFO: task syz.6.810:9953 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.810 state:D stack:26112 pid:9953 tgid:9932 ppid:6087 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5257 [inline] __schedule+0x14bc/0x5030 kernel/sched/core.c:6864 __schedule_loop kernel/sched/core.c:6946 [inline] schedule+0x165/0x360 kernel/sched/core.c:6961 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7018 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1539 inode_lock_shared include/linux/fs.h:1042 [inline] lookup_slow+0x46/0x70 fs/namei.c:1871 walk_component+0x2d2/0x400 fs/namei.c:2190 lookup_last fs/namei.c:2691 [inline] path_lookupat+0x163/0x430 fs/namei.c:2715 filename_lookup+0x212/0x570 fs/namei.c:2744 user_path_at+0x3a/0x60 fs/namei.c:3536 __do_sys_chdir fs/open.c:558 [inline] __se_sys_chdir+0x91/0x280 fs/open.c:552 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fef1f58f749 RSP: 002b:00007fef20450038 EFLAGS: 00000246 ORIG_RAX: 0000000000000050 RAX: ffffffffffffffda RBX: 00007fef1f7e6180 RCX: 00007fef1f58f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000140 RBP: 00007fef1f613f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fef1f7e6218 R14: 00007fef1f7e6180 R15: 00007ffd6140b068 INFO: task syz.6.810:9959 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.810 state:D stack:27648 pid:9959 tgid:9932 ppid:6087 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5257 [inline] __schedule+0x14bc/0x5030 kernel/sched/core.c:6864 __schedule_loop kernel/sched/core.c:6946 [inline] schedule+0x165/0x360 kernel/sched/core.c:6961 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7018 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591 inode_lock include/linux/fs.h:1027 [inline] open_last_lookups fs/namei.c:4506 [inline] path_openat+0xabf/0x3d90 fs/namei.c:4753 do_filp_open+0x1fa/0x410 fs/namei.c:4783 do_sys_openat2+0x121/0x1c0 fs/open.c:1432 do_sys_open fs/open.c:1447 [inline] __do_sys_openat fs/open.c:1463 [inline] __se_sys_openat fs/open.c:1458 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1458 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fef1f58f749 RSP: 002b:00007fef2042f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fef1f7e6270 RCX: 00007fef1f58f749 RDX: 0000000000008042 RSI: 00002000000000c0 RDI: ffffffffffffff9c RBP: 00007fef1f613f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fef1f7e6308 R14: 00007fef1f7e6270 R15: 00007ffd6140b068 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5588: #0: ffff888034b950a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/u8:13/5981: #0: ffff88802f9e7148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x841/0x15e0 kernel/workqueue.c:3236 #1: ffffc9000ac3fb80 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15e0 kernel/workqueue.c:3237 #2: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194 4 locks held by syz.6.810/9933: 1 lock held by syz.6.810/9951: #0: ffff8880592f4c68 (&type->i_mutex_dir_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1042 [inline] #0: ffff8880592f4c68 (&type->i_mutex_dir_key#9){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1871 1 lock held by syz.6.810/9953: #0: ffff8880592f4c68 (&type->i_mutex_dir_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1042 [inline] #0: ffff8880592f4c68 (&type->i_mutex_dir_key#9){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1871 2 locks held by syz.6.810/9959: #0: ffff8880672de420 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:509 #1: ffff8880592f4c68 (&type->i_mutex_dir_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #1: ffff8880592f4c68 (&type->i_mutex_dir_key#9){++++}-{4:4}, at: open_last_lookups fs/namei.c:4506 [inline] #1: ffff8880592f4c68 (&type->i_mutex_dir_key#9){++++}-{4:4}, at: path_openat+0xabf/0x3d90 fs/namei.c:4753 4 locks held by syz.9.1090/11156: #0: ffff88805cb830a0 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:289 [inline] #0: ffff88805cb830a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:335 [inline] #0: ffff88805cb830a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:366 [inline] #0: ffff88805cb830a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0x5c/0x200 drivers/tty/tty_ldisc.c:780 #1: ffff88807ae9f0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: __tty_ldisc_lock_nested drivers/tty/tty_ldisc.c:295 [inline] #1: ffff88807ae9f0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:337 [inline] #1: ffff88807ae9f0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:366 [inline] #1: ffff88807ae9f0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_release+0x80/0x200 drivers/tty/tty_ldisc.c:780 #2: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2144 #3: ffffffff8df43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #3: ffffffff8df43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xfb5/0x1000 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 9933 Comm: syz.6.810 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:preempt_count_add+0x23/0x1a0 kernel/sched/core.c:5720 Code: 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 53 49 bf 00 00 00 00 00 fc ff df 48 c7 c0 e0 a3 81 99 48 c1 e8 03 42 0f b6 04 38 <84> c0 0f 85 f1 00 00 00 83 3d de 7c f0 17 00 75 07 65 8b 05 25 39 RSP: 0018:ffffc90003c6fa60 EFLAGS: 00000a02 RAX: 0000000000000004 RBX: ffff8880592f3d10 RCX: ffff888076aa5b80 RDX: 0000000000000002 RSI: 0000000000000003 RDI: 0000000000000001 RBP: ffff8880672de000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff5200078df40 R12: ffff8880592f3c90 R13: ffff8880592f3d10 R14: ffffc90000c51f40 R15: dffffc0000000000 FS: 00007fef204926c0(0000) GS:ffff888125eba000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f398f1b7198 CR3: 000000007d226000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock+0x12/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] insert_inode_locked+0x1e1/0x5d0 fs/inode.c:1843 ntfs_new_inode+0xc8/0x100 fs/ntfs3/fsntfs.c:1675 ntfs_create_inode+0x606/0x32a0 fs/ntfs3/inode.c:1309 ntfs_mkdir+0x3d/0x50 fs/ntfs3/namei.c:215 vfs_mkdir+0x512/0x5b0 fs/namei.c:5099 do_mkdirat+0x276/0x4b0 fs/namei.c:5133 __do_sys_mkdirat fs/namei.c:5155 [inline] __se_sys_mkdirat fs/namei.c:5153 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:5153 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fef1f58de97 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 02 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:00007fef20491e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fef20491ef0 RCX: 00007fef1f58de97 RDX: 00000000000001ff RSI: 00002000000000c0 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000000c0 R13: 00007fef20491eb0 R14: 0000000000000000 R15: 0000000000000000