INFO: task syz.8.3035:17163 blocked in I/O wait for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.3035 state:D stack:26400 pid:17163 tgid:17160 ppid:12656 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x1259/0x6920 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7362 io_schedule+0x8a/0xf0 kernel/sched/core.c:8190 folio_wait_bit_common+0x3c0/0xac0 mm/filemap.c:1329 folio_lock include/linux/pagemap.h:1186 [inline] migrate_folio_unmap mm/migrate.c:1261 [inline] migrate_pages_batch+0x81d/0x46f0 mm/migrate.c:1919 migrate_pages_sync+0x4db/0x880 mm/migrate.c:2063 migrate_pages+0x1a83/0x2850 mm/migrate.c:2145 compact_zone+0x2643/0x4640 mm/compaction.c:2698 compact_node+0x17f/0x2c0 mm/compaction.c:2945 compact_nodes mm/compaction.c:2967 [inline] sysctl_compaction_handler mm/compaction.c:3018 [inline] sysctl_compaction_handler+0x141/0x210 mm/compaction.c:3005 proc_sys_call_handler+0x47f/0x5a0 fs/proc/proc_sysctl.c:600 iter_file_splice_write+0x830/0x10b0 fs/splice.c:736 do_splice_from fs/splice.c:936 [inline] direct_splice_actor+0x192/0x690 fs/splice.c:1159 splice_direct_to_actor+0x345/0xa30 fs/splice.c:1103 do_splice_direct_actor fs/splice.c:1202 [inline] do_splice_direct+0x174/0x240 fs/splice.c:1228 do_sendfile+0xadc/0xe20 fs/read_write.c:1371 __do_sys_sendfile64 fs/read_write.c:1426 [inline] __se_sys_sendfile64 fs/read_write.c:1418 [inline] __x64_sys_sendfile64+0x154/0x220 fs/read_write.c:1418 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbb5059e0d9 RSP: 002b:00007fbb514a0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fbb50825fa0 RCX: 00007fbb5059e0d9 RDX: 00002000000000c0 RSI: 0000000000000003 RDI: 0000000000000004 RBP: 00007fbb50635024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbb50826038 R14: 00007fbb50825fa0 R15: 00007fffe159e4e8 Showing all locks held in the system: locks held by khungtaskd/43: 1, last CPU#0: #0: ffffffff8ede9d40 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8ede9d40 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8ede9d40 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6793 locks held by getty/5527: 2, last CPU#2: #0: ffff8880235800a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffff8880235804f8 (&tty->atomic_write_lock){+.+.}-{4:4}, at: tty_write_lock drivers/tty/tty_io.c:939 [inline] #1: ffff8880235804f8 (&tty->atomic_write_lock){+.+.}-{4:4}, at: iterate_tty_write drivers/tty/tty_io.c:958 [inline] #1: ffff8880235804f8 (&tty->atomic_write_lock){+.+.}-{4:4}, at: file_tty_write.isra.0+0x24b/0x890 drivers/tty/tty_io.c:1054 locks held by udevd/11294: 1, on CPU#0: #0: ffff888028fe3350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990 locks held by syz.8.3035/17163: 1, on CPU#2: #0: ffff88802ee84460 (sb_writers#3){.+.+}-{0:0}, at: splice_direct_to_actor+0x345/0xa30 fs/splice.c:1103 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 43 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x21f/0x2a0 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 2: NMI backtrace for cpu 2 CPU: 2 UID: 0 PID: 20232 Comm: syz.1.3816 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1163 [inline] RIP: 0010:debug_check_no_obj_freed+0x210/0x630 lib/debugobjects.c:1201 Code: 00 00 48 89 c2 31 f6 49 89 df 4c 89 74 24 28 48 c1 ea 03 89 f3 42 80 3c 22 00 0f 85 dd 00 00 00 48 8d 78 18 83 c3 01 4c 8b 30 <48> 89 fa 48 c1 ea 03 42 80 3c 22 00 0f 85 27 03 00 00 48 8b 50 18 RSP: 0018:ffffc900039ff740 EFLAGS: 00000012 RAX: ffff88802befd4d0 RBX: 0000000000000020 RCX: ffffffff81e6ac68 RDX: 1ffff110057dfa9a RSI: 0000000000000000 RDI: ffff88802befd4e8 RBP: ffffc900039ff870 R08: 0000000000000001 R09: fffff5200073fed6 R10: 0000000000000003 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff88812b095000 R14: ffff88803cfd87a8 R15: ffff88812b096000 FS: 0000000000000000(0000) GS:ffff8880d5da2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000559484e2fce8 CR3: 000000002a719000 CR4: 0000000000352ef0 Call Trace: __free_pages_prepare mm/page_alloc.c:1425 [inline] free_pages_prepare+0x3a7/0xe00 mm/page_alloc.c:1463 __free_contig_range_common+0x14f/0x250 mm/page_alloc.c:7060 __free_contig_range mm/page_alloc.c:7105 [inline] free_pages_bulk+0x12a/0x200 mm/page_alloc.c:5322 vm_area_free_pages+0xad/0x2b0 mm/vmalloc.c:3462 vfree mm/vmalloc.c:3511 [inline] vfree+0x108/0x730 mm/vmalloc.c:3485 kcov_put kernel/kcov.c:447 [inline] kcov_put kernel/kcov.c:443 [inline] kcov_close+0x34/0x60 kernel/kcov.c:554 __fput+0x3ff/0xb50 fs/file_table.c:512 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x951/0x2ae0 kernel/exit.c:1008 do_group_exit+0xd5/0x2a0 kernel/exit.c:1151 get_signal+0x1ec7/0x21e0 kernel/signal.c:3046 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x139/0x700 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline] do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fac5679e0d9 Code: Unable to access opcode bytes at 0x7fac5679e0af. RSP: 002b:00007fac576b1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: fffffffffffffff5 RBX: 00007fac56a25fa0 RCX: 00007fac5679e0d9 RDX: 0000000000000090 RSI: 00002000000000c0 RDI: 0000000000000005 RBP: 00007fac56835024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fac56a26038 R14: 00007fac56a25fa0 R15: 00007fffdd86c7a8