syzbot

INFO: task kworker/u4:1:144 blocked for more than 143 seconds.
      Not tainted 5.15.178-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:1    state:D stack:19488 pid:  144 ppid:     2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 rwsem_down_write_slowpath+0xf0c/0x16a0 kernel/locking/rwsem.c:1165
 f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:528
 f2fs_write_inode+0x4be/0x660 fs/f2fs/inode.c:738
 write_inode fs/fs-writeback.c:1495 [inline]
 __writeback_single_inode+0x644/0xe30 fs/fs-writeback.c:1705
 writeback_sb_inodes+0xbce/0x1a40 fs/fs-writeback.c:1930
 __writeback_inodes_wb+0x114/0x400 fs/fs-writeback.c:2001
 wb_writeback+0x465/0xc50 fs/fs-writeback.c:2106
 wb_check_background_flush fs/fs-writeback.c:2172 [inline]
 wb_do_writeback fs/fs-writeback.c:2260 [inline]
 wb_workfn+0xd07/0x1130 fs/fs-writeback.c:2288
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8cb1fce0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
4 locks held by kworker/u4:1/144:
 #0: ffff88814478c938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc9000163fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffff88802ba180e0 (&type->s_umount_key#43){.+.+}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418
 #3: ffff88807b7fd1b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:528
2 locks held by getty/3927:
 #0: ffff88814d3b3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002cd62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
5 locks held by syz-executor435/4180:

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4180 Comm: syz-executor435 Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:__read_once_word_nocheck+0x0/0x10 include/asm-generic/rwonce.h:67
Code: e1 07 38 c1 0f 8c dc fc ff ff 48 89 df e8 68 9d 91 00 48 ba 00 00 00 00 00 fc ff df e9 c5 fc ff ff 66 0f 1f 84 00 00 00 00 00 <48> 8b 07 c3 cc cc cc cc cc cc cc cc cc cc cc cc 31 c0 81 ff 03 00
RSP: 0018:ffffc900031be060 EFLAGS: 00000287
RAX: ffffc900031bea60 RBX: ffffc900031bea58 RCX: ffffffff8e35a9e8
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffc900031bea58
RBP: ffffc900031c0000 R08: 0000000000000001 R09: ffffc900031be210
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff1d59c30
R13: 1ffffffff1d59c30 R14: ffffc900031b8000 R15: ffffc900031be120
FS:  00005555768e8380(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005625d45e7600 CR3: 000000001eee9000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 deref_stack_reg arch/x86/kernel/unwind_orc.c:360 [inline]
 unwind_next_frame+0xb35/0x1fa0 arch/x86/kernel/unwind_orc.c:539
 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x80 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1705 [inline]
 slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731
 slab_free mm/slub.c:3499 [inline]
 kmem_cache_free+0x91/0x1f0 mm/slub.c:3515
 submit_bio_checks+0x323/0x1940 block/blk-core.c:899
 __submit_bio+0x5a1/0x850 block/blk-core.c:911
 __submit_bio_noacct_mq block/blk-core.c:997 [inline]
 submit_bio_noacct+0x955/0xb30 block/blk-core.c:1027
 submit_bio+0x2dd/0x560 block/blk-core.c:1089
 f2fs_submit_page_read+0x24c/0x2c0 fs/f2fs/data.c:1050
 f2fs_get_read_data_page+0x455/0x6b0 fs/f2fs/data.c:1224
 gc_data_segment fs/f2fs/gc.c:1504 [inline]
 do_garbage_collect+0x4972/0x7540 fs/f2fs/gc.c:1671
 f2fs_gc+0x9d2/0x1c30 fs/f2fs/gc.c:1765
 f2fs_balance_fs+0x4e8/0x6a0 fs/f2fs/segment.c:529
 f2fs_map_blocks+0x265b/0x3720 fs/f2fs/data.c:1700
 expand_inode_data+0x5dd/0xa40 fs/f2fs/file.c:1709
 f2fs_fallocate+0x42d/0x910 fs/f2fs/file.c:1805
 vfs_fallocate+0x54a/0x6b0 fs/open.c:308
 do_vfs_ioctl+0x2317/0x2b70 fs/ioctl.c:853
 __do_sys_ioctl fs/ioctl.c:872 [inline]
 __se_sys_ioctl+0x81/0x160 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f7d162b1b99
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:00007ffddaafb458 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007f7d162b1b99
RDX: 00000000200000c0 RSI: 0000000040305828 RDI: 0000000000000004
RBP: 00007f7d1632a5f0 R08: 00005555768e94c0 R09: 00005555768e94c0
R10: 00005555768e94c0 R11: 0000000000000246 R12: 00007ffddaafb480
R13: 00007ffddaafb6a8 R14: 431bde82d7b634db R15: 00007f7d162fa03b
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.732 msecs