INFO: task syz.7.2653:14875 blocked for more than 143 seconds.
Not tainted 6.16.0-rc3-next-20250627-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.2653 state:D stack:23704 pid:14875 tgid:14874 ppid:13718 task_flags:0x400040 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5313 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6696
__schedule_loop kernel/sched/core.c:6774 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6789
io_schedule+0x80/0xd0 kernel/sched/core.c:7634
folio_wait_bit_common+0x6b0/0xb90 mm/filemap.c:1317
folio_lock include/linux/pagemap.h:1114 [inline]
migrate_folio_unmap mm/migrate.c:1182 [inline]
migrate_pages_batch+0x13a6/0x2830 mm/migrate.c:1806
migrate_pages_sync mm/migrate.c:1956 [inline]
migrate_pages+0x2038/0x2930 mm/migrate.c:2038
compact_zone+0x23e1/0x4ab0 mm/compaction.c:2683
compact_node mm/compaction.c:2952 [inline]
compact_nodes mm/compaction.c:2974 [inline]
sysctl_compaction_handler+0x3a4/0x7b0 mm/compaction.c:3025
proc_sys_call_handler+0x509/0x7c0 fs/proc/proc_sysctl.c:600
iter_file_splice_write+0x93a/0x1000 fs/splice.c:738
do_splice_from fs/splice.c:935 [inline]
direct_splice_actor+0x101/0x160 fs/splice.c:1158
splice_direct_to_actor+0x5a5/0xcc0 fs/splice.c:1102
do_splice_direct_actor fs/splice.c:1201 [inline]
do_splice_direct+0x181/0x270 fs/splice.c:1227
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/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f33e9b8e929
RSP: 002b:00007f33ea95e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f33e9db5fa0 RCX: 00007f33e9b8e929
RDX: 0000200000002080 RSI: 0000000000000005 RDI: 0000000000000006
RBP: 00007f33e9c10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000023b R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f33e9db5fa0 R15: 00007fff9d9d1338
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e33bf20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e33bf20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e33bf20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5588:
#0: ffff888034f9e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036b32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by udevd/12405:
#0: ffff888143369358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
2 locks held by kworker/u8:8/13426:
#0: ffff88801e727148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#0: ffff88801e727148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322
#1: ffffc9000e427bc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline]
#1: ffffc9000e427bc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322
1 lock held by syz.7.2653/14875:
#0: ffff8880776c4428 (sb_writers#3){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160 fs/splice.c:1157
1 lock held by syz.9.3688/18932:
#0: ffffffff8e341900 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3792
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc3-next-20250627-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
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: 13426 Comm: kworker/u8:8 Not tainted 6.16.0-rc3-next-20250627-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__kasan_check_byte+0x2c/0x40 mm/kasan/common.c:561
Code: 1f 00 41 56 53 48 89 f3 49 89 fe e8 5e 14 00 00 84 c0 75 16 be 01 00 00 00 4c 89 f7 31 d2 48 89 d9 89 c3 e8 c6 03 00 00 89 d8 <5b> 41 5e c3 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90
RSP: 0018:ffffc9000e427968 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff8b44138f RCX: 5918702661dfa600
RDX: 0000000000000000 RSI: ffffffff8b44138f RDI: 1ffffffff1c677e4
RBP: ffffffff8b441372 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f85587 R12: 0000000000000002
R13: ffffffff8e33bf20 R14: ffffffff8e33bf20 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881259e6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa47ff81178 CR3: 000000007680a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000097 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
kasan_check_byte include/linux/kasan.h:399 [inline]
lock_acquire+0x8d/0x360 kernel/locking/lockdep.c:5845
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719
process_one_work kernel/workqueue.c:3239 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3322
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3403
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245