INFO: task syz.3.2015:10491 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.2015 state:D stack:25768 pid:10491 tgid:10490 ppid:5843 task_flags:0x400040 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 io_schedule+0xbf/0x130 kernel/sched/core.c:7903 folio_wait_bit_common+0x3d6/0x9e0 mm/filemap.c:1317 folio_lock include/linux/pagemap.h:1133 [inline] migrate_folio_unmap mm/migrate.c:1246 [inline] migrate_pages_batch+0x147d/0x3bd0 mm/migrate.c:1873 migrate_pages_sync+0x4c5/0x8a0 mm/migrate.c:2023 migrate_pages+0x1b67/0x23b0 mm/migrate.c:2105 compact_zone+0x2018/0x4760 mm/compaction.c:2647 compact_node+0x1a4/0x2d0 mm/compaction.c:2916 compact_nodes mm/compaction.c:2938 [inline] sysctl_compaction_handler mm/compaction.c:2989 [inline] sysctl_compaction_handler+0x141/0x210 mm/compaction.c:2976 proc_sys_call_handler+0x43d/0x570 fs/proc/proc_sysctl.c:600 iter_file_splice_write+0xa21/0x12e0 fs/splice.c:738 do_splice_from fs/splice.c:938 [inline] direct_splice_actor+0x192/0x6c0 fs/splice.c:1161 splice_direct_to_actor+0x342/0xa30 fs/splice.c:1105 do_splice_direct_actor fs/splice.c:1204 [inline] do_splice_direct+0x174/0x240 fs/splice.c:1230 do_sendfile+0xb06/0xe50 fs/read_write.c:1370 __do_sys_sendfile64 fs/read_write.c:1425 [inline] __se_sys_sendfile64 fs/read_write.c:1417 [inline] __x64_sys_sendfile64+0x154/0x220 fs/read_write.c:1417 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3ee058eec9 RSP: 002b:00007f3ee1419038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f3ee07e5fa0 RCX: 00007f3ee058eec9 RDX: 00002000000000c0 RSI: 0000000000000003 RDI: 0000000000000004 RBP: 00007f3ee0611f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3ee07e6038 R14: 00007f3ee07e5fa0 R15: 00007ffcdd1f2258 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e5c15a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c15a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c15a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by getty/5609: #0: ffff88814d5460a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by udevd/5834: #0: ffff888142f95358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 3 locks held by kworker/u8:15/9890: #0: ffff88814728a148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000c497d10 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff8880b853a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:636 2 locks held by kworker/u8:43/9921: #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000fb57d10 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 1 lock held by syz.3.2015/10491: #0: ffff888032254428 (sb_writers#3){.+.+}-{0:0}, at: splice_direct_to_actor+0x342/0xa30 fs/splice.c:1105 2 locks held by syz.2.4426/16031: #0: ffff88807a76e298 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{4:4}, at: pfkey_sendmsg+0x427/0x850 net/key/af_key.c:3698 #1: ffffffff9059be28 (pfkey_mutex){+.+.}-{4:4}, at: pfkey_register+0xf4/0x910 net/key/af_key.c:1700 1 lock held by syz.6.4434/16063: #0: ffffffff8e5cca00 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3815 2 locks held by modprobe/16091: #0: ffff8880b853a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:636 #1: ffff8880b8524088 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:220 [inline] #1: ffff8880b8524088 (psi_seq){-.-.}-{0:0}, at: __schedule+0x1861/0x5de0 kernel/sched/core.c:6955 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 9891 Comm: kworker/u8:16 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:native_irq_enable arch/x86/include/asm/irqflags.h:42 [inline] RIP: 0010:arch_local_irq_enable arch/x86/include/asm/irqflags.h:119 [inline] RIP: 0010:arch_local_irq_restore arch/x86/include/asm/irqflags.h:159 [inline] RIP: 0010:lock_release+0x17d/0x2f0 kernel/locking/lockdep.c:5892 Code: b8 ff ff ff ff 65 0f c1 05 f8 4d 3f 12 83 f8 01 0f 85 1d 01 00 00 9c 58 f6 c4 02 0f 85 08 01 00 00 41 f7 c5 00 02 00 00 74 01 48 8b 44 24 10 65 48 2b 05 0d 0c 3f 12 0f 85 58 01 00 00 48 83 RSP: 0018:ffffc9000c4a7ae0 EFLAGS: 00000006 RAX: 0000000000000046 RBX: ffffffff8e5c15a0 RCX: ffffc9000c4a7aec RDX: 0000000000000002 RSI: ffffffff8de2d7c8 RDI: ffffffff8c163400 RBP: 00000000000003f6 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8b61d2e5 R13: 0000000000000202 R14: ffff888052db2440 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8881247b2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbef5d5aa40 CR3: 000000007422f000 CR4: 00000000003526f0 Call Trace: rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0x89a/0x1030 net/batman-adv/network-coding.c:719 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245