INFO: task syz.4.7818:23199 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.7818 state:D stack:23840 pid:23199 tgid:23198 ppid:11768 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
io_schedule+0x80/0xd0 kernel/sched/core.c:7792
folio_wait_bit_common+0x6b0/0xb80 mm/filemap.c:1323
folio_lock include/linux/pagemap.h:1159 [inline]
migrate_folio_unmap mm/migrate.c:1249 [inline]
migrate_pages_batch+0x14cd/0x35e0 mm/migrate.c:1890
migrate_pages_sync mm/migrate.c:2034 [inline]
migrate_pages+0x2006/0x28e0 mm/migrate.c:2116
compact_zone+0x25ba/0x4760 mm/compaction.c:2647
compact_node mm/compaction.c:2916 [inline]
compact_nodes mm/compaction.c:2938 [inline]
sysctl_compaction_handler+0x3a1/0x7b0 mm/compaction.c:2989
proc_sys_call_handler+0x4cb/0x700 fs/proc/proc_sysctl.c:600
iter_file_splice_write+0x972/0x10b0 fs/splice.c:738
do_splice_from fs/splice.c:938 [inline]
direct_splice_actor+0x101/0x160 fs/splice.c:1161
splice_direct_to_actor+0x5a8/0xcc0 fs/splice.c:1105
do_splice_direct_actor fs/splice.c:1204 [inline]
do_splice_direct+0x181/0x270 fs/splice.c:1230
do_sendfile+0x4da/0x7e0 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/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f67bb38f749
RSP: 002b:00007f67bc28a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f67bb5e5fa0 RCX: 00007f67bb38f749
RDX: 0000200000000180 RSI: 0000000000000003 RDI: 0000000000000004
RBP: 00007f67bb413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000003fffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f67bb5e6038 R14: 00007f67bb5e5fa0 R15: 00007ffd6a39c898
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e33f8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e33f8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e33f8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:10/3437:
#0: ffff88801c387148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc9000bf37b80 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
2 locks held by getty/5580:
#0: ffff88814d6650a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211
3 locks held by kworker/1:3/5887:
#0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc9000424fb80 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffffffff8e3453f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#2: ffffffff8e3453f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:956
1 lock held by udevd/21460:
#0: ffff8880262b3358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962
3 locks held by kworker/1:4/22636:
1 lock held by syz.4.7818/23199:
#0: ffff88806e90a420 (sb_writers#3){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160 fs/splice.c:1160
1 lock held by syz.6.9020/25878:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
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]
__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:363 [inline]
watchdog+0xe40/0xe90 kernel/hung_task.c:557
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 25878 Comm: syz.6.9020 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:check_preemption_disabled+0x40/0x120 lib/smp_processor_id.c:53
Code: 08 65 8b 05 c6 41 5d 07 65 8b 0d bb 41 5d 07 f7 c1 ff ff ff 7f 74 23 65 48 8b 0d 9b 41 5d 07 48 3b 4c 24 08 0f 85 cc 00 00 00 <48> 83 c4 10 5b 41 5e 41 5f 5d e9 81 cd 02 00 cc 48 c7 04 24 00 00
RSP: 0018:ffffc9000b687458 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffffffff90584901 RCX: ecaee8962db51e00
RDX: ffffc9000b687601 RSI: ffffffff8be243c0 RDI: ffffffff8be24380
RBP: dffffc0000000000 R08: ffffc9000b687c60 R09: 0000000000000000
R10: ffffc9000b687638 R11: fffff520016d0ec9 R12: ffffc9000b687c70
R13: ffffffff81746f85 R14: ffffffff8e33f8a0 R15: ffffffff81746f85
FS: 0000000000000000(0000) GS:ffff888125ae1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000140 CR3: 000000000e138000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:751
trace_lock_release include/trace/events/lock.h:69 [inline]
lock_release+0x4b/0x3b0 kernel/locking/lockdep.c:5879
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:897 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0x1ab1/0x23d0 arch/x86/kernel/unwind_orc.c:695
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 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+0xbc8/0xd30 mm/page_alloc.c:2943
vfree+0x25a/0x400 mm/vmalloc.c:3471
kcov_put kernel/kcov.c:439 [inline]
kcov_close+0x28/0x50 kernel/kcov.c:535
__fput+0x44c/0xa70 fs/file_table.c:468
task_work_run+0x1d4/0x260 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6c5/0x2310 kernel/exit.c:971
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: f0df:0x9ade3b5fcbc7f515
Code: Unable to access opcode bytes at 0x9ade3b5fcbc7f4eb.
RSP: 000b:ef1a4a14bea5489e EFLAGS: 00050f47 ORIG_RAX: 28f5d0669e63ef2d
RAX: b4479265aea11ea0 RBX: c4d7cfc1cfb8fa39 RCX: d58af6dd852ac5bf
RDX: 8d6f5a4031d65101 RSI: ff4dd0ac2272ad10 RDI: 826f04d17a53db6c
RBP: 7a62a17fc0673791 R08: a9b7dd6a329c7eb9 R09: 3611b8ee2ae2943c
R10: 2e5d0286e8a92051 R11: 42c1d6567a18f68c R12: 3e91493a4aeb0fdd
R13: 21068466b382b223 R14: 0395461d403a0691 R15: f6eee41c95dd6d7b