INFO: task syz.0.1732:9319 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1732 state:D stack:27904 pid:9319 ppid:4268 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189 lock_rename include/linux/fs.h:-1 [inline] do_renameat2+0x423/0xc70 fs/namei.c:4966 __do_sys_renameat2 fs/namei.c:5060 [inline] __se_sys_renameat2 fs/namei.c:5057 [inline] __x64_sys_renameat2+0xce/0xe0 fs/namei.c:5057 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f059078eec9 RSP: 002b:00007f0591653038 EFLAGS: 00000246 ORIG_RAX: 000000000000013c RAX: ffffffffffffffda RBX: 00007f05909e6090 RCX: 00007f059078eec9 RDX: 0000000000000004 RSI: 0000200000000140 RDI: 0000000000000004 RBP: 00007f0590811f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000200 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f05909e6128 R14: 00007f05909e6090 R15: 00007ffd927732b8 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b570 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2bd90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by getty/4030: #0: ffff88814d136098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 3 locks held by syz.0.1732/9310: 2 locks held by syz.0.1732/9319: #0: ffff888024624460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:393 #1: ffff888051c42218 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: lock_rename include/linux/fs.h:-1 [inline] #1: ffff888051c42218 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: do_renameat2+0x423/0xc70 fs/namei.c:4966 2 locks held by ext4lazyinit/9312: 1 lock held by syz-executor/10888: #0: ffff888024aac0e0 (&type->s_umount_key#70){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9312 Comm: ext4lazyinit Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:check_preemption_disabled+0x1/0x110 lib/smp_processor_id.c:13 Code: 20 74 bc 8c 4c 89 f6 e8 fd 1c 17 fa e9 6e ff ff ff 00 00 cc cc 00 00 cc cc 48 c7 c7 80 fc de 8a 48 c7 c6 c0 fc de 8a eb 00 55 <41> 57 41 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 RSP: 0018:ffffc9001745fa10 EFLAGS: 00000282 RAX: ffffffff81aa4025 RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff888053a5bb80 RSI: ffffffff8adefcc0 RDI: ffffffff8adefc80 RBP: ffffc9001745fb58 R08: dffffc0000000000 R09: fffffbfff215c449 R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: 0000000000000007 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff888140d33f00 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fce9687c000 CR3: 0000000049f7e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline] rcu_is_watching+0x11/0xa0 kernel/rcu/tree.c:721 rcu_read_lock include/linux/rcupdate.h:792 [inline] mapping_get_entry mm/filemap.c:1878 [inline] __filemap_get_folio+0x12e/0xdd0 mm/filemap.c:1943 pagecache_get_page+0x26/0x250 mm/folio-compat.c:110 find_or_create_page include/linux/pagemap.h:646 [inline] grow_dev_page fs/buffer.c:946 [inline] grow_buffers fs/buffer.c:1011 [inline] __getblk_slow fs/buffer.c:1038 [inline] __getblk_gfp+0x2d8/0xb20 fs/buffer.c:1333 sb_getblk include/linux/buffer_head.h:356 [inline] ext4_read_block_bitmap_nowait+0x1fb/0x960 fs/ext4/balloc.c:482 ext4_mb_prefetch+0x440/0x620 fs/ext4/mballoc.c:2582 ext4_run_li_request fs/ext4/super.c:3654 [inline] ext4_lazyinit_thread+0x749/0x1800 fs/ext4/super.c:3780 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295