INFO: task kworker/u4:1:3549 blocked for more than 143 seconds. Not tainted 5.15.112-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:1 state:D stack:24192 pid: 3549 ppid: 2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5026 [inline] __schedule+0x12c4/0x4590 kernel/sched/core.c:6372 schedule+0x11b/0x1f0 kernel/sched/core.c:6455 rwsem_down_write_slowpath+0xebb/0x15c0 kernel/locking/rwsem.c:1157 __down_write_common kernel/locking/rwsem.c:1284 [inline] __down_write kernel/locking/rwsem.c:1293 [inline] down_write+0x164/0x170 kernel/locking/rwsem.c:1542 f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:529 f2fs_write_inode+0x4c3/0x540 fs/f2fs/inode.c:727 write_inode fs/fs-writeback.c:1478 [inline] __writeback_single_inode+0x644/0xe30 fs/fs-writeback.c:1683 writeback_sb_inodes+0xbf0/0x1a50 fs/fs-writeback.c:1908 __writeback_inodes_wb+0x114/0x400 fs/fs-writeback.c:1979 wb_writeback+0x465/0xc50 fs/fs-writeback.c:2084 wb_check_old_data_flush fs/fs-writeback.c:2184 [inline] wb_do_writeback fs/fs-writeback.c:2237 [inline] wb_workfn+0xc55/0x1130 fs/fs-writeback.c:2266 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2307 worker_thread+0xaca/0x1280 kernel/workqueue.c:2454 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Showing all locks held in the system: 1 lock held by ksoftirqd/1/20: #0: ffff8880b9b39698 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 1 lock held by khungtaskd/27: #0: ffffffff8c91c5a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3261: #0: ffff888024428098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900024bb2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1da0 drivers/tty/n_tty.c:2147 2 locks held by syz-executor287/3542: 4 locks held by kworker/u4:1/3549: #0: ffff888142bbe938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2280 #1: ffffc90002defd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2282 #2: ffff8880790960e0 (&type->s_umount_key#45){.+.+}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418 #3: ffff888018801108 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:529 2 locks held by dhcpcd/4211: #0: ffff888079af2120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1649 [inline] #0: ffff888079af2120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2a/0xc90 net/packet/af_packet.c:3162 #1: ffffffff8c920ae8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffffffff8c920ae8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:840 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.112-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb 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:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3542 Comm: syz-executor287 Not tainted 5.15.112-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023 RIP: 0010:lock_acquire+0x239/0x4f0 kernel/locking/lockdep.c:5625 Code: 4c 89 f7 e8 59 e5 66 00 48 c7 44 24 60 00 00 00 00 9c 8f 44 24 60 42 80 3c 2b 00 74 08 4c 89 f7 e8 bc e4 66 00 f6 44 24 61 02 <0f> 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e RSP: 0018:ffffc90002dbdaa0 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 1ffff920005b7b60 RCX: ffffffff816316d2 RDX: dffffc0000000000 RSI: ffffffff8a8b0e00 RDI: ffffffff8ad85d40 RBP: ffffc90002dbdbe8 R08: dffffc0000000000 R09: fffffbfff1f7903b R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920005b7b5c R13: dffffc0000000000 R14: ffffc90002dbdb00 R15: 0000000000000246 FS: 00007f8efb923700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555556ffa2b8 CR3: 0000000071f80000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: down_read+0x45/0x2e0 kernel/locking/rwsem.c:1488 check_valid_map fs/f2fs/gc.c:881 [inline] gc_data_segment fs/f2fs/gc.c:1450 [inline] do_garbage_collect+0x20d8/0x7600 fs/f2fs/gc.c:1670 f2fs_gc+0x9e5/0x1ad0 fs/f2fs/gc.c:1764 f2fs_balance_fs+0x4e8/0x6a0 fs/f2fs/segment.c:530 f2fs_write_single_data_page+0xc4f/0x18a0 fs/f2fs/data.c:2868 f2fs_write_cache_pages fs/f2fs/data.c:3082 [inline] __f2fs_write_data_pages fs/f2fs/data.c:3233 [inline] f2fs_write_data_pages+0x17de/0x2c00 fs/f2fs/data.c:3260 do_writepages+0x481/0x730 mm/page-writeback.c:2364 filemap_fdatawrite_wbc+0x1d6/0x230 mm/filemap.c:400 __filemap_fdatawrite_range mm/filemap.c:433 [inline] file_write_and_wait_range+0x1cb/0x2b0 mm/filemap.c:810 f2fs_do_sync_file+0x650/0x19d0 fs/f2fs/file.c:274 generic_write_sync include/linux/fs.h:2913 [inline] f2fs_file_write_iter+0x476/0xb80 fs/f2fs/file.c:4358 __kernel_write+0x5b1/0xa60 fs/read_write.c:539 __dump_emit+0x264/0x3a0 fs/coredump.c:875 dump_user_range+0x91/0x320 fs/coredump.c:949 elf_core_dump+0x3c7d/0x4570 fs/binfmt_elf.c:2285 do_coredump+0x1852/0x31e0 fs/coredump.c:826 get_signal+0xc06/0x14e0 kernel/signal.c:2875 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:172 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:314 exc_page_fault+0x342/0x740 arch/x86/mm/fault.c:1544 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568 RIP: 0033:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 002b:00000000200001c8 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f8effe2c6d8 RCX: 00007f8effd981f9 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000080004000 RBP: 00007f8effe2c6d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8effe2c6dc R13: 9958090000000000 R14: 0030656c69662f2e R15: 0000000000022000 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.303 msecs