INFO: task syz.4.5791:23653 blocked for more than 145 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.5791 state:D stack:24200 pid:23653 tgid:23652 ppid:14338 task_flags:0x400040 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
io_schedule+0x81/0xe0 kernel/sched/core.c:7871
folio_wait_bit_common+0x6b5/0xb90 mm/filemap.c:1330
folio_lock include/linux/pagemap.h:1141 [inline]
migrate_folio_unmap mm/migrate.c:1241 [inline]
migrate_pages_batch+0x10ab/0x2ec0 mm/migrate.c:1882
migrate_pages_sync mm/migrate.c:2026 [inline]
migrate_pages+0x201d/0x2910 mm/migrate.c:2108
compact_zone+0x238f/0x49d0 mm/compaction.c:2647
compact_node mm/compaction.c:2916 [inline]
compact_nodes mm/compaction.c:2938 [inline]
sysctl_compaction_handler+0x3a4/0x7b0 mm/compaction.c:2989
proc_sys_call_handler+0x4cc/0x700 fs/proc/proc_sysctl.c:600
iter_file_splice_write+0x97a/0x10f0 fs/splice.c:738
do_splice_from fs/splice.c:938 [inline]
direct_splice_actor+0x104/0x160 fs/splice.c:1161
splice_direct_to_actor+0x5b3/0xcd0 fs/splice.c:1105
do_splice_direct_actor fs/splice.c:1204 [inline]
do_splice_direct+0x187/0x270 fs/splice.c:1230
do_sendfile+0x4ec/0x7f0 fs/read_write.c:1370
__do_sys_sendfile64 fs/read_write.c:1425 [inline]
__se_sys_sendfile64+0xd9/0x190 fs/read_write.c:1417
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa11d13f749
RSP: 002b:00007fa11b3a6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fa11d395fa0 RCX: 00007fa11d13f749
RDX: 00002000000000c0 RSI: 0000000000000003 RDI: 0000000000000004
RBP: 00007fa11d1c3f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa11d396038 R14: 00007fa11d395fa0 R15: 00007ffe0f27a4c8
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:4/66:
2 locks held by getty/5552:
#0: ffff88823bf3c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222
1 lock held by udevd/5952:
#0: ffff8880244ae4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:945
1 lock held by udevd/5960:
#0: ffff8880244aa4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:945
1 lock held by syz.4.5791/23653:
#0: ffff8880330b4480 (sb_writers#3){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160 fs/splice.c:1160
3 locks held by syz.9.6033/24670:
2 locks held by syz.3.6037/24679:
2 locks held by syz.0.6038/24685:
4 locks held by syz.8.6042/24705:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 24705 Comm: syz.8.6042 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:146 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:153 [inline]
RIP: 0010:lock_release+0x29a/0x3e0 kernel/locking/lockdep.c:5892
Code: c7 09 56 f6 8c e8 66 bc 24 09 b8 ff ff ff ff 65 0f c1 05 59 f1 06 10 83 f8 01 75 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b
RSP: 0018:ffffc9000d137098 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000002 RCX: 11cc02b2e1074b00
RDX: 0000000000000001 RSI: ffffffff8cf65609 RDI: ffffffff8b3ddfe0
RBP: ffff888028766588 R08: ffff88805d29ac17 R09: 1ffff1100ba53582
R10: dffffc0000000000 R11: ffffed100ba53583 R12: 0000000000000001
R13: 0000000000000001 R14: ffff88805d29abd8 R15: ffff888028765a00
FS: 0000000000000000(0000) GS:ffff888126df6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000000d3a6000 CR4: 00000000003526f0
Call Trace:
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
_raw_spin_unlock_irqrestore+0x70/0x110 kernel/locking/spinlock.c:194
raw_spin_unlock_irqrestore_wake include/linux/sched/wake_q.h:94 [inline]
rtlock_slowlock kernel/locking/rtmutex.c:1896 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x16d/0x3e0 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:44 [inline]
filemap_remove_folio+0xd0/0x200 mm/filemap.c:254
truncate_inode_folio+0x5d/0x70 mm/truncate.c:176
shmem_undo_range+0x3a9/0x14b0 mm/shmem.c:1115
shmem_truncate_range mm/shmem.c:1231 [inline]
shmem_evict_inode+0x272/0xa70 mm/shmem.c:1359
evict+0x504/0x9c0 fs/inode.c:810
__dentry_kill+0x209/0x660 fs/dcache.c:669
dput+0x19f/0x2b0 fs/dcache.c:911
__fput+0x69d/0xa80 fs/file_table.c:476
task_work_run+0x1d4/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6b5/0x2300 kernel/exit.c:966
do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
get_signal+0x125d/0x1310 kernel/signal.c:3034
arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f140b39f749
Code: Unable to access opcode bytes at 0x7f140b39f71f.
RSP: 002b:00007f14095c40e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f140b5f6188 RCX: 00007f140b39f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f140b5f6188
RBP: 00007f140b5f6180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f140b5f6218 R14: 00007ffe4f0cc7d0 R15: 00007ffe4f0cc8b8