INFO: task kworker/u4:1:144 blocked for more than 143 seconds. Not tainted 5.15.158-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:1 state:D stack:21760 pid: 144 ppid: 2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 rwsem_down_write_slowpath+0xf0c/0x16a0 kernel/locking/rwsem.c:1165 f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:528 f2fs_write_inode+0x4c3/0x540 fs/f2fs/inode.c:727 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:300 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:1/144: #0: ffff88801458c938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc900010bfd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffff8880157ca0e0 (&type->s_umount_key#43){.+.+}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418 #3: ffff88807a6ed108 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:528 2 locks held by getty/3259: #0: ffff8880251d8098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc9000249b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158 5 locks held by syz-executor371/3523: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.158-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __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:300 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3523 Comm: syz-executor371 Not tainted 5.15.158-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:memset_erms+0xb/0x10 arch/x86/lib/memset_64.S:65 Code: 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3 aa <4c> 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 01 01 RSP: 0018:ffffc900025b6d18 EFLAGS: 00000202 RAX: ffffffff81a9b800 RBX: ffffffff91586c98 RCX: 0000000000000000 RDX: 0000000000000028 RSI: 0000000000000000 RDI: ffffc900025b6de8 RBP: ffffc900025b6e70 R08: dffffc0000000000 R09: ffffc900025b6dc0 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920004b6db4 R13: ffffc900025b6dc0 R14: dffffc0000000000 R15: 0000000000000c00 FS: 000055555717a380(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f51896c1580 CR3: 0000000070826000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mempool_alloc+0xa4/0x590 mm/mempool.c:379 bio_alloc_bioset+0x132/0x8c0 block/bio.c:466 f2fs_grab_read_bio+0x9f/0x720 fs/f2fs/data.c:990 f2fs_submit_page_read+0xb8/0x2c0 fs/f2fs/data.c:1035 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:1698 f2fs_fallocate+0x35a/0x820 fs/f2fs/file.c:1788 vfs_fallocate+0x54a/0x6b0 fs/open.c:308 ksys_fallocate fs/open.c:331 [inline] __do_sys_fallocate fs/open.c:339 [inline] __se_sys_fallocate fs/open.c:337 [inline] __x64_sys_fallocate+0xb9/0x100 fs/open.c:337 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: 0033:0x7f17ad3a0d99 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:00007fffdccb91d8 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f17ad3a0d99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007f17ad41a5f0 R08: 000055555717b4c0 R09: 000055555717b4c0 R10: 0000000002000402 R11: 0000000000000246 R12: 00007fffdccb9200 R13: 00007fffdccb9428 R14: 431bde82d7b634db R15: 00007f17ad3ea03b INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.400 msecs