INFO: task syz.1.1535:11094 blocked for more than 145 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1535 state:D stack:24496 pid:11094 ppid:5789 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
io_schedule+0x80/0xd0 kernel/sched/core.c:9022
folio_wait_bit_common+0x6eb/0xf70 mm/filemap.c:1329
migrate_folio_unmap mm/migrate.c:1162 [inline]
migrate_pages_batch+0x1364/0x3430 mm/migrate.c:1672
migrate_pages_sync mm/migrate.c:1865 [inline]
migrate_pages+0x2085/0x2920 mm/migrate.c:1947
compact_zone+0x21df/0x44b0 mm/compaction.c:2515
compact_node+0x167/0x2b0 mm/compaction.c:2807
compact_nodes mm/compaction.c:2820 [inline]
sysctl_compaction_handler+0xf9/0x1a0 mm/compaction.c:2866
proc_sys_call_handler+0x45d/0x6d0 fs/proc/proc_sysctl.c:599
do_iter_readv_writev fs/read_write.c:-1 [inline]
do_iter_write+0x79a/0xc70 fs/read_write.c:860
iter_file_splice_write+0x66f/0xc50 fs/splice.c:736
do_splice_from fs/splice.c:933 [inline]
direct_splice_actor+0xe8/0x130 fs/splice.c:1142
splice_direct_to_actor+0x2f0/0x870 fs/splice.c:1088
do_splice_direct+0x1b7/0x2c0 fs/splice.c:1194
do_sendfile+0x5dc/0xf70 fs/read_write.c:1254
__do_sys_sendfile64 fs/read_write.c:1316 [inline]
__se_sys_sendfile64+0xda/0x190 fs/read_write.c:1308
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f50f5b8eec9
RSP: 002b:00007f50f6aa6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f50f5de5fa0 RCX: 00007f50f5b8eec9
RDX: 00002000000000c0 RSI: 0000000000000005 RDI: 0000000000000006
RBP: 00007f50f5c11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f50f5de6038 R14: 00007f50f5de5fa0 R15: 00007ffd3082cd08
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by getty/5550:
#0: ffff88802c97c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
1 lock held by udevd/10238:
#0: ffff888141ba94c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:788
1 lock held by syz.1.1535/11094:
#0: ffff888023444418 (sb_writers#3){.+.+}-{0:0}, at: do_sendfile+0x5b9/0xf70 fs/read_write.c:1253
2 locks held by kworker/u4:14/11573:
#0: ffff888140a86938 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140a86938 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000ba9fd00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000ba9fd00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 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+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 2947 Comm: kworker/u4:9 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:check_preemption_disabled+0x60/0x110 lib/smp_processor_id.c:19
Code: 00 48 3b 4c 24 08 0f 85 c4 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d c3 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 <74> cc 65 4c 8b 3d 86 38 95 75 41 f6 47 2f 04 74 0a 41 83 bf 10 04
RSP: 0018:ffffc9000c1c7a08 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffff88802b6d28dc RCX: 0000000080000000
RDX: 0000000000000000 RSI: ffffffff8aaac9c0 RDI: ffffffff8afc63c0
RBP: ffffc9000c1c7b50 R08: ffffffff8e4a82ef R09: 1ffffffff1c9505d
R10: dffffc0000000000 R11: fffffbfff1c9505e R12: ffffffff8a36c2a2
R13: dffffc0000000000 R14: ffff88802b6d1e00 R15: 1ffff92001838f54
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f06271b4198 CR3: 000000001a6b5000 CR4: 00000000003506e0
Call Trace:
lockdep_recursion_inc kernel/locking/lockdep.c:462 [inline]
lock_release+0x155/0x8b0 kernel/locking/lockdep.c:5773
rcu_lock_release include/linux/rcupdate.h:344 [inline]
rcu_read_unlock include/linux/rcupdate.h:819 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
batadv_nc_worker+0x291/0x610 net/batman-adv/network-coding.c:719
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293