INFO: task syz.7.3335:16000 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.3335 state:D stack:25032 pid:16000 ppid:10791 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747 sync_bdevs+0x1af/0x330 block/bdev.c:1076 ksys_sync+0xc6/0x170 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fdfc4d9cdd9 RSP: 002b:00007fdfc5d17028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007fdfc5015fa0 RCX: 00007fdfc4d9cdd9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fdfc5015fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdfc5016038 R14: 00007fdfc5015fa0 R15: 00007ffcbace3288 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5529: #0: ffff88814bf4e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217 1 lock held by udevd/6567: #0: ffff8880223db4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805 1 lock held by syz.7.3335/16000: #0: ffff8880223db4c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1af/0x330 block/bdev.c:1076 4 locks held by syz.2.4391/19032: #0: ffff888024e44418 (sb_writers#21){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412 #1: ffff8880738446d0 (&type->i_mutex_dir_key#15/1){+.+.}-{3:3}, at: lock_rename include/linux/fs.h:-1 [inline] #1: ffff8880738446d0 (&type->i_mutex_dir_key#15/1){+.+.}-{3:3}, at: do_renameat2+0x439/0xce0 fs/namei.c:4972 #2: ffff888073845020 (&sb->s_type->i_mutex_key#24){++++}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline] #2: ffff888073845020 (&sb->s_type->i_mutex_key#24){++++}-{3:3}, at: lock_two_inodes fs/inode.c:1172 [inline] #2: ffff888073845020 (&sb->s_type->i_mutex_key#24){++++}-{3:3}, at: lock_two_nondirectories+0x1ab/0x270 fs/inode.c:1192 #3: ffff8880738462c0 (&sb->s_type->i_mutex_key#24/4){+.+.}-{3:3}, at: vfs_rename+0x6b9/0xed0 fs/namei.c:4851 5 locks held by syz.2.4391/19069: 3 locks held by udevadm/19067: 3 locks held by syz.8.4397/19070: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf3d/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 19067 Comm: udevadm Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:lookup_object lib/debugobjects.c:196 [inline] RIP: 0010:lookup_object_or_alloc lib/debugobjects.c:565 [inline] RIP: 0010:debug_object_activate+0xb1/0x4f0 lib/debugobjects.c:711 Code: 4c 89 7c 24 10 4d 8b 2c 24 45 31 ff eb 07 4d 8b 6d 00 41 ff c7 4d 85 ed 74 3c 49 8d 6d 18 48 89 e8 48 c1 e8 03 42 80 3c 30 00 <74> 08 48 89 ef e8 55 1e ae fd 48 39 5d 00 0f 84 fc 00 00 00 4c 89 RSP: 0018:ffffc9000da6fd40 EFLAGS: 00000046 RAX: 1ffff1100be28850 RBX: ffff8880786d2f00 RCX: 0000000000000001 RDX: ffffffff97510120 RSI: 0000000000000004 RDI: ffffc9000da6fc20 RBP: ffff88805f144280 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52001b4df84 R12: ffffffff97510110 R13: ffff88805f144268 R14: dffffc0000000000 R15: 0000000000000002 FS: 00007fc147dfc880(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3120bff8 CR3: 000000006b596000 CR4: 00000000003506f0 Call Trace: debug_rcu_head_queue kernel/rcu/rcu.h:227 [inline] __call_rcu_common kernel/rcu/tree.c:2706 [inline] call_rcu+0xa6/0x950 kernel/rcu/tree.c:2837 __do_sys_close fs/open.c:1573 [inline] __se_sys_close+0x15f/0x220 fs/open.c:1558 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc147715a67 Code: 44 00 00 48 83 ec 10 48 63 ff 45 31 c9 45 31 c0 6a 01 31 c9 e8 ca 19 f9 ff 48 83 c4 18 c3 0f 1f 44 00 00 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 61 b3 0d 00 f7 d8 64 89 02 b8 RSP: 002b:00007ffe87275678 EFLAGS: 00000297 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 00005557c28f82a0 RCX: 00007fc147715a67 RDX: 00007fc1477efea0 RSI: 00005557c290adf0 RDI: 0000000000000005 RBP: 00007fc1477efff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000000 R13: 3d45505954564544 R14: 3d5845444e494649 R15: 3d454d414e564544