INFO: task kworker/u4:1:144 blocked for more than 143 seconds. Not tainted 5.15.180-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:1 state:D stack:25728 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+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 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8cb1f4e0 ( rcu_read_lock ){....}-{1:2} , at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:1/144: #0: ffff8880191cb938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc9000169fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffff888029f120e0 (&type->s_umount_key#43){.+.+}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418 #3: ffff888077f511b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:528 2 locks held by getty/3924: #0: ffff88802ca05098 (&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 7 locks held by syz-executor356/4180: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.180-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 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:212 [inline] watchdog+0xe72/0xeb0 kernel/hung_task.c:369 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4180 Comm: syz-executor356 Not tainted 5.15.180-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:unwind_next_frame+0x142d/0x1fa0 arch/x86/kernel/unwind_orc.c:616 Code: 00 80 3b 00 0f 85 85 02 00 00 80 3d 4f 6b be 0c 00 0f 85 78 02 00 00 c6 05 42 6b be 0c 01 48 c7 c7 60 83 a8 8a e9 0e fa ff ff 01 00 00 00 e8 b9 b5 1e 00 65 8b 0d 9a d2 c9 7e b0 01 85 c9 0f RSP: 0018:ffffc9000325e068 EFLAGS: 00000212 RAX: ffffc90003260000 RBX: ffffc9000325e130 RCX: ffffc9000325ff38 RDX: dffffc0000000000 RSI: ffffc9000325ff20 RDI: ffffc9000325e128 RBP: ffffc9000325ff30 R08: ffffc9000325ff20 R09: ffffc9000325e170 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff1d1ade6 R13: 1ffffffff1d1ade6 R14: ffffc90003258000 R15: ffffc9000325e120 FS: 00005555654db380(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555654e46f8 CR3: 0000000073f33000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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+0x2d56/0x3720 fs/f2fs/data.c:1746 expand_inode_data+0x5dd/0xa40 fs/f2fs/file.c:1716 f2fs_fallocate+0x435/0x910 fs/f2fs/file.c:1818 vfs_fallocate+0x54a/0x6b0 fs/open.c:308 file_ioctl fs/ioctl.c:-1 [inline] 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/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f6d8e0ebd59 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:00007ffe2270b858 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00002000000000c0 RCX: 00007f6d8e0ebd59 RDX: 00002000000000c0 RSI: 0000000040305828 RDI: 0000000000000004 RBP: 00002000000000e0 R08: 00005555654dc4c0 R09: 00005555654dc4c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000000d0 R13: 00002000000000c8 R14: 00002000000000c2 R15: 00007f6d8e13503b INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.182 msecs