INFO: task syz-executor386:5684 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor386 state:D stack:26448 pid:5684 tgid:5684 ppid:5662 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383 rwsem_down_write_slowpath+0x87d/0x1080 kernel/locking/rwsem.c:1215 __down_write_common kernel/locking/rwsem.c:1347 [inline] __down_write kernel/locking/rwsem.c:1356 [inline] down_write+0x1bc/0x200 kernel/locking/rwsem.c:1632 inode_lock include/linux/fs.h:1024 [inline] blkdev_fallocate+0x260/0x530 block/fops.c:882 vfs_fallocate+0x65a/0x7e0 fs/open.c:338 ksys_fallocate fs/open.c:362 [inline] __do_sys_fallocate fs/open.c:367 [inline] __se_sys_fallocate fs/open.c:365 [inline] __x64_sys_fallocate+0xbf/0x110 fs/open.c:365 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7926241579 RSP: 002b:00007ffe42844328 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7926241579 RDX: 0000000000002000 RSI: 0000000000000010 RDI: 0000000000000003 RBP: 00000000000f4240 R08: 0000000000000009 R09: 0000000000000009 R10: 000000100007c000 R11: 0000000000000246 R12: 00000000000264a9 R13: 00007ffe4284433c R14: 00007ffe42844350 R15: 00007ffe42844340 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by klogd/4980: 2 locks held by getty/5382: #0: ffff888035bb70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 2 locks held by syz-executor386/5677: 1 lock held by syz-executor386/5684: #0: ffff8880238887e8 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #0: ffff8880238887e8 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: blkdev_fallocate+0x260/0x530 block/fops.c:882 1 lock held by syz-executor386/5689: #0: ffff8880238887e8 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #0: ffff8880238887e8 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: blkdev_fallocate+0x260/0x530 block/fops.c:882 1 lock held by syz-executor386/5693: #0: ffff8880238887e8 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #0: ffff8880238887e8 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: blkdev_fallocate+0x260/0x530 block/fops.c:882 1 lock held by syz-executor386/5700: #0: ffff8880238887e8 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #0: ffff8880238887e8 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: blkdev_fallocate+0x260/0x530 block/fops.c:882 ============================================= 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 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [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:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 15 Comm: ksoftirqd/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:__lock_acquire+0x6d5/0x2cf0 kernel/locking/lockdep.c:5220 Code: 9e 90 0b 00 00 48 83 3c 24 00 75 1e 48 83 fb ff 0f 94 c0 83 3d 9b d6 d5 18 00 b1 01 0f 84 4c 20 00 00 84 c9 0f 84 4e 20 00 00 <49> 89 5d 00 45 8b be 98 0b 00 00 4d 85 ff 0f 84 88 00 00 00 41 83 RSP: 0018:ffffc90000147580 EFLAGS: 00000002 RAX: 0000000000000007 RBX: 7819e49154d45b3f RCX: ffffffff94161a88 RDX: 0000000000000008 RSI: ffff88801deeaac8 RDI: ffff88801dee9f00 RBP: 0000000000000000 R08: ffffffff8177927f R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb59c60 R12: 00000000ffffff03 R13: ffff88801deeaac8 R14: ffff88801dee9f00 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888124f4b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055556531e7a8 CR3: 000000000e946000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] class_rcu_constructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495 __unwind_start+0x514/0x660 arch/x86/kernel/unwind_orc.c:787 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0xc1e/0xd10 mm/page_alloc.c:2950 rcu_do_batch kernel/rcu/tree.c:2645 [inline] rcu_core+0x78b/0x10a0 kernel/rcu/tree.c:2897 handle_softirqs+0x225/0x840 kernel/softirq.c:622 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1076 smpboot_thread_fn+0x57c/0xa80 kernel/smpboot.c:160 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.096 msecs