syzbot

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:
 <TASK>
 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
 </TASK>

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:
 <TASK>
 __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
 </TASK>
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:
 <NMI>
 </NMI>
 <TASK>
 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
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.797 msecs