INFO: task syz-executor:7763 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22352 pid:7763 tgid:7763 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x14ea/0x5050 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0x164/0x360 kernel/sched/core.c:6964 bit_wait+0x11/0xd0 kernel/sched/wait_bit.c:240 __wait_on_bit+0xb9/0x310 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_bit include/linux/wait_bit.h:77 [inline] gfs2_glock_wait+0xbd/0x2a0 fs/gfs2/glock.c:1268 gfs2_glock_nq_init fs/gfs2/glock.h:252 [inline] __gfs2_lookup+0x134/0x2a0 fs/gfs2/inode.c:999 __lookup_slow+0x2b7/0x410 fs/namei.c:1866 lookup_slow+0x53/0x70 fs/namei.c:1883 walk_component fs/namei.c:2229 [inline] lookup_last fs/namei.c:2730 [inline] path_lookupat+0x3f5/0x8c0 fs/namei.c:2754 filename_lookup+0x256/0x5d0 fs/namei.c:2783 user_path_at+0x3a/0x60 fs/namei.c:3576 ksys_umount fs/namespace.c:2058 [inline] __do_sys_umount fs/namespace.c:2066 [inline] __se_sys_umount fs/namespace.c:2064 [inline] __x64_sys_umount+0xf6/0x170 fs/namespace.c:2064 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdcc439c117 RSP: 002b:00007fffb7f89db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00007fdcc440471f RCX: 00007fdcc439c117 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffb7f89e70 RBP: 00007fffb7f89e70 R08: 0000000000000000 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffb7f8af60 R13: 00007fdcc440471f R14: 0000000000182b03 R15: 00007fffb7f8d120 Showing all locks held in the system: 1 lock held by khungtaskd/32: #0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 1 lock held by dhcpcd/5484: #0: ffffffff8f9ac148 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f9ac148 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x32b/0x1b30 net/ipv4/devinet.c:1120 2 locks held by getty/5578: #0: ffff88814cdc40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by kworker/1:3/302: 1 lock held by syz-executor/7763: #0: ffff88804dfe5e08 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1042 [inline] #0: ffff88804dfe5e08 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1882 2 locks held by udevd/9511: #0: ffff888034802420 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff88807d1b9ca8 (&type->i_mutex_dir_key#5){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #1: ffff88807d1b9ca8 (&type->i_mutex_dir_key#5){++++}-{4:4}, at: open_last_lookups fs/namei.c:4546 [inline] #1: ffff88807d1b9ca8 (&type->i_mutex_dir_key#5){++++}-{4:4}, at: path_openat+0xb53/0x3e20 fs/namei.c:4793 2 locks held by syz.0.15392/17824: 2 locks held by syz.4.15399/17869: #0: ffffffff8f9ac148 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8f9ac148 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 #1: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #1: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:956 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [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+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5189 Comm: udevd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:146 [inline] RIP: 0010:lock_acquire+0xd4/0x330 kernel/locking/lockdep.c:5869 Code: 2c 0b 00 00 00 0f 85 aa 00 00 00 4c 89 74 24 10 4d 89 fe 9c 41 5f fa 48 c7 c7 d3 2c ce 8d e8 a3 dc f6 09 65 ff 05 fc a7 52 11 <45> 31 c9 4c 89 7c 24 08 41 f7 c7 00 02 00 00 41 0f 94 c1 4c 89 ef RSP: 0018:ffffc900039ffbd8 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 0000000000000000 RSI: ffffffff8dce2cd3 RDI: ffffffff8c073a00 RBP: ffffffff826b8acc R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed100f6e7401 R12: 0000000000000002 R13: ffffffff8e55a360 R14: 0000000000000000 R15: 0000000000000246 FS: 00007f46aaf44880(0000) GS:ffff8881257f5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fffaa353b1c CR3: 0000000034be2000 CR4: 0000000000350ef0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] kernfs_root+0x38/0x230 fs/kernfs/kernfs-internal.h:75 kernfs_root_is_locked fs/kernfs/kernfs-internal.h:109 [inline] kernfs_parent+0x51/0x190 fs/kernfs/kernfs-internal.h:133 kernfs_get_target_path fs/kernfs/symlink.c:83 [inline] kernfs_getlink fs/kernfs/symlink.c:122 [inline] kernfs_iop_get_link+0x30c/0x6c0 fs/kernfs/symlink.c:140 vfs_readlink+0x24a/0x540 fs/namei.c:6149 do_readlinkat+0x222/0x510 fs/stat.c:590 __do_sys_readlink fs/stat.c:613 [inline] __se_sys_readlink fs/stat.c:610 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:610 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f46ab03e3a7 Code: 00 00 90 48 83 ec 10 48 63 ff 45 31 c9 45 31 c0 6a 00 31 c9 e8 8a 20 f9 ff 48 83 c4 18 c3 0f 1f 44 00 00 b8 59 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 21 ba 0d 00 f7 d8 64 89 02 48 RSP: 002b:00007fff62c89818 EFLAGS: 00000246 ORIG_RAX: 0000000000000059 RAX: ffffffffffffffda RBX: 00007fff62c89cf0 RCX: 00007f46ab03e3a7 RDX: 0000000000000400 RSI: 00007fff62c89820 RDI: 00007fff62c89cf0 RBP: 00007fff62c89820 R08: 0000000000000075 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000400 R13: 00005631182fa100 R14: 0000000000000001 R15: 00007fff62c8b5f0