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:23904 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: ffff888141f9a938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc9000125fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffff888077d880e0 (&type->s_umount_key#43){.+.+}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418 #3: ffff8880753d91b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:528 2 locks held by getty/3922: #0: ffff88814d280098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025c62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158 6 locks held by syz-executor318/4187: ============================================= NMI backtrace for cpu 0 CPU: 0 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4187 Comm: syz-executor318 Not tainted 5.15.180-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:write_comp_data kernel/kcov.c:226 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x4/0x80 kernel/kcov.c:300 Code: 89 f8 89 f6 48 c7 44 0a 08 05 00 00 00 48 89 44 0a 10 48 89 74 0a 18 4c 89 44 0a 20 49 ff c1 4c 89 09 c3 0f 1f 00 4c 8b 04 24 <65> 48 8b 0d 94 29 82 7e 65 8b 05 95 29 82 7e 25 00 01 ff 00 74 10 RSP: 0018:ffffc9000314e558 EFLAGS: 00000246 RAX: 1ffffd4000379011 RBX: ffffea0001bc8088 RCX: ffffffff83ac879a RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffea0001bc8080 R08: ffffffff83ac87ca R09: fffff94000379011 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffd4000379011 R13: dffffc0000000000 R14: ffffea0001bc8048 R15: ffffea0001bc8080 FS: 0000555589145380(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000560115467600 CR3: 0000000073a79000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: _compound_head include/linux/page-flags.h:198 [inline] PageSwapCache include/linux/page-flags.h:413 [inline] page_file_mapping include/linux/mm.h:1652 [inline] F2FS_P_SB fs/f2fs/f2fs.h:1952 [inline] f2fs_finish_read_bio+0x54a/0xa00 fs/f2fs/data.c:150 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: 0033:0x7f2372e86d59 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:00007ffd921e75a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00002000000000c0 RCX: 00007f2372e86d59 RDX: 00002000000000c0 RSI: 0000000040305828 RDI: 0000000000000004 RBP: 00002000000000e0 R08: 00005555891464c0 R09: 00005555891464c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000000d0 R13: 00002000000000c8 R14: 00002000000000c2 R15: 00007f2372ed003b INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.644 msecs