INFO: task syz.0.449:8946 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.449 state:D stack:28600 pid:8946 tgid:8[ 475.376024][ T38] task:syz.0.449 state:D stack:28600 pid:8946 tgid:8929 ppid:5811 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1028 [inline] open_last_lookups fs/namei.c:4580 [inline] path_openat+0xb5e/0x38a0 fs/namei.c:4827 do_file_open+0x23e/0x4a0 fs/namei.c:4859 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f52831ac799 RSP: 002b:00007f52813c4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f5283426180 RCX: 00007f52831ac799 RDX: 000000000000275a RSI: 0000200000000200 RDI: ffffffffffffff9c RBP: 00007f5283242c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5283426218 R14: 00007f5283426180 R15: 00007ffe0d053a18 Showing all locks held in the system: 5 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/38: #0: ffffffff8ddcba80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcba80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcba80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 5 locks held by kworker/u8:6/138: 2 locks held by getty/5553: #0: ffff888037bad0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 1 lock held by udevd/5919: 1 lock held by udevd/5929: #0: ffff88802268cb70 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline] #0: ffff88802268cb70 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:854 1 lock held by udevd/5958: 4 locks held by syz.0.449/8931: 2 locks held by syz.0.449/8946: #0: ffff88802a3a0480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff8880603c3430 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff8880603c3430 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: open_last_lookups fs/namei.c:4580 [inline] #1: ffff8880603c3430 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: path_openat+0xb5e/0x38a0 fs/namei.c:4827 1 lock held by syz-executor/9070: #0: ffff88805ef740d0 (&type->s_umount_key#75){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88805ef740d0 (&type->s_umount_key#75){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88805ef740d0 (&type->s_umount_key#75){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 3 locks held by syz-executor/10107: 1 lock held by syz.7.685/11006: #0: ffff8880675500d0 (&type->s_umount_key#66/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 2 locks held by syz.8.683/11013: 3 locks held by dhcpcd-run-hook/11068: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 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: 5919 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x28/0x80 kernel/kcov.c:217 Code: 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0d a8 f7 89 10 65 8b 35 c9 f7 89 10 81 e6 00 00 ff 00 ba 00 01 00 00 23 91 a4 0b 00 00 <89> d7 09 f7 74 11 85 f6 75 39 85 d2 74 35 83 b9 74 16 00 00 00 74 RSP: 0018:ffffc900053673f8 EFLAGS: 00000246 RAX: ffffffff8b1c5de3 RBX: ffff88803dcf9a40 RCX: ffff88802c401e80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: ffffc900053675f0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000003 R12: 0000000000000005 R13: dffffc0000000000 R14: ffff88803e58ec00 R15: 000000000000000a FS: 00007f290fa1c880(0000) GS:ffff888126439000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f290f0aa000 CR3: 000000003e3ba000 CR4: 00000000003526f0 Call Trace: mt_validate_nulls lib/maple_tree.c:7139 [inline] mt_validate+0x3c83/0x4340 lib/maple_tree.c:7179 validate_mm+0xd4/0x4c0 mm/vma.c:649 __split_vma+0x8e4/0xa30 mm/vma.c:567 vms_gather_munmap_vmas+0x4fa/0x1370 mm/vma.c:1429 do_vmi_align_munmap+0x2c7/0x4d0 mm/vma.c:1576 do_vmi_munmap+0x252/0x2d0 mm/vma.c:1633 __vm_munmap+0x22c/0x3d0 mm/vma.c:3254 __do_sys_munmap mm/mmap.c:1078 [inline] __se_sys_munmap mm/mmap.c:1075 [inline] __x64_sys_munmap+0x60/0x70 mm/mmap.c:1075 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f290fb81097 Code: 73 01 c3 48 8b 0d 61 2d 0d 00 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 0b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 31 2d 0d 00 f7 d8 64 89 01 48 RSP: 002b:00007ffe78ab2d98 EFLAGS: 00000246 ORIG_RAX: 000000000000000b RAX: ffffffffffffffda RBX: 0000559cbbb42e70 RCX: 00007f290fb81097 RDX: 0000559cbbb42798 RSI: 0000000000000200 RDI: 00007f290f0ba000 RBP: 0000559cbbb410c0 R08: 0000559cbbb3d3d0 R09: 0000000000000003 R10: 0000559cbbb410b0 R11: 0000000000000246 R12: 00007f291025e7c0 R13: 00007f291026039c R14: 0000000000000022 R15: 0000000000000001