INFO: task kworker/u8:1:12 blocked for more than 143 seconds. Not tainted 6.12.0-rc6-syzkaller-00169-g906bd684e4b1 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:1 state:D stack:24080 pid:12 tgid:12 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x17fa/0x4bd0 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6782 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6839 rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write+0x1d7/0x220 kernel/locking/rwsem.c:1578 f2fs_down_write fs/f2fs/f2fs.h:2199 [inline] f2fs_balance_fs+0x5b0/0x7a0 fs/f2fs/segment.c:448 f2fs_write_inode+0x3a0/0x4d0 fs/f2fs/inode.c:787 write_inode fs/fs-writeback.c:1503 [inline] __writeback_single_inode+0x711/0x10d0 fs/fs-writeback.c:1723 writeback_sb_inodes+0x80c/0x1370 fs/fs-writeback.c:1954 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2025 wb_writeback+0x42f/0xbd0 fs/fs-writeback.c:2136 wb_check_background_flush fs/fs-writeback.c:2206 [inline] wb_do_writeback fs/fs-writeback.c:2294 [inline] wb_workfn+0xc58/0x1090 fs/fs-writeback.c:2321 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 4 locks held by kworker/u8:1/12: #0: ffff8881422b9148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff8881422b9148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90000117d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000117d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffff88807e3060e0 (&type->s_umount_key#44){.+.+}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff888012ff1350 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2199 [inline] #3: ffff888012ff1350 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x5b0/0x7a0 fs/f2fs/segment.c:448 1 lock held by ksoftirqd/0/16: 1 lock held by khungtaskd/30: #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 2 locks held by getty/5595: #0: ffff888031bb90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 5 locks held by syz-executor514/5850: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc6-syzkaller-00169-g906bd684e4b1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5850 Comm: syz-executor514 Not tainted 6.12.0-rc6-syzkaller-00169-g906bd684e4b1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 RIP: 0010:__kasan_check_write+0x4/0x20 mm/kasan/shadow.c:37 Code: 31 d2 e9 6f e6 ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <89> f6 48 8b 0c 24 ba 01 00 00 00 e9 3c e6 ff ff 66 2e 0f 1f 84 00 RSP: 0018:ffffc90003fa6b40 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000002 RCX: ffffffff81ccf56e RDX: ffff88807e07bc00 RSI: 0000000000000004 RDI: ffffea0001e089b4 RBP: 1ffffd40003c1136 R08: ffffffff81ccf58f R09: 1ffffd40003c1136 R10: dffffc0000000000 R11: fffff940003c1137 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffffffff81ccf4ae R15: ffffea0001e089b4 FS: 0000555568fb4380(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000556439a1f600 CR3: 000000007aa5a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_add_unless include/linux/atomic/atomic-instrumented.h:1517 [inline] page_ref_add_unless include/linux/page_ref.h:238 [inline] folio_ref_add_unless include/linux/page_ref.h:248 [inline] folio_try_get+0x114/0x350 include/linux/page_ref.h:264 filemap_get_entry+0x240/0x3b0 mm/filemap.c:1852 __filemap_get_folio+0x71/0xbd0 mm/filemap.c:1887 pagecache_get_page+0x2c/0x200 mm/folio-compat.c:81 find_get_page_flags include/linux/pagemap.h:830 [inline] f2fs_grab_cache_page+0x2b/0x320 fs/f2fs/f2fs.h:2784 __get_node_page+0x131/0xfc0 fs/f2fs/node.c:1449 is_alive fs/f2fs/gc.c:1149 [inline] gc_data_segment fs/f2fs/gc.c:1581 [inline] do_garbage_collect+0x259d/0x8210 fs/f2fs/gc.c:1829 f2fs_gc+0xf90/0x2ff0 fs/f2fs/gc.c:1933 f2fs_balance_fs+0x5f8/0x7a0 fs/f2fs/segment.c:450 f2fs_map_blocks+0x44ec/0x4f10 fs/f2fs/data.c:1788 f2fs_expand_inode_data+0x622/0xbb0 fs/f2fs/file.c:1811 f2fs_fallocate+0x448/0x960 fs/f2fs/file.c:1914 vfs_fallocate+0x569/0x6e0 fs/open.c:333 ksys_fallocate fs/open.c:356 [inline] __do_sys_fallocate fs/open.c:364 [inline] __se_sys_fallocate fs/open.c:362 [inline] __x64_sys_fallocate+0xbd/0x110 fs/open.c:362 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd1f9525dd9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcad636958 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd1f9525dd9 RDX: 0000000000000009 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007fd1f959f5f0 R08: 0000555568fb54c0 R09: 0000555568fb54c0 R10: 0000000000000022 R11: 0000000000000246 R12: 00007ffcad636980 R13: 00007ffcad636ba8 R14: 431bde82d7b634db R15: 00007fd1f956f03b INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.797 msecs