INFO: task syz-executor:6234 blocked for more than 143 seconds. Not tainted 6.16.0-rc3-syzkaller-00044-g7595b66ae9de #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21960 pid:6234 tgid:6234 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216 sync_inodes_sb+0x1bb/0xa10 fs/fs-writeback.c:2833 sync_filesystem+0x17a/0x230 fs/sync.c:64 generic_shutdown_super+0x6f/0x2c0 fs/super.c:622 kill_block_super+0x44/0x90 fs/super.c:1755 xfs_kill_sb+0x15/0x50 fs/xfs/xfs_super.c:2318 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1417 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f26fb58fc57 RSP: 002b:00007fff957098a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f26fb610925 RCX: 00007f26fb58fc57 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff95709960 RBP: 00007fff95709960 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff9570a9f0 R13: 00007f26fb610925 R14: 00000000000335d9 R15: 00007fff9570aa30 Showing all locks held in the system: 9 locks held by kworker/u8:0/12: 1 lock held by khungtaskd/32: #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 4 locks held by kworker/u8:9/3515: 2 locks held by kworker/u8:10/3532: #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffff8880b8723f08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987 2 locks held by getty/5585: #0: ffff8880351c20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/5821: #0: ffff88805a5320e0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88805a5320e0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88805a5320e0 (&type->s_umount_key#90){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffff8880253727d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8880253727d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831 1 lock held by udevd/5835: 2 locks held by syz-executor/6234: #0: ffff888032fc20e0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888032fc20e0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888032fc20e0 (&type->s_umount_key#90){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffff8880254687d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8880254687d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831 1 lock held by syz.2.303/9060: #0: ffffffff8e144978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8e144978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998 1 lock held by dhcpcd-run-hook/9132: #0: ffff8880b8639e18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:606 4 locks held by udevd/9136: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Not tainted 6.16.0-rc3-syzkaller-00044-g7595b66ae9de #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 3515 Comm: kworker/u8:9 Not tainted 6.16.0-rc3-syzkaller-00044-g7595b66ae9de #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: writeback wb_workfn (flush-7:5) RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: 8b 3d 14 e8 f8 0b 48 89 de 5b e9 c3 90 56 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 d0 99 92 65 8b 15 f8 83 d9 10 81 e2 00 01 ff 00 RSP: 0018:ffffc9000b8e51e0 EFLAGS: 00000293 RAX: ffffffff8b5c423e RBX: ffffc9000b8e52a0 RCX: ffff8880315d8000 RDX: 0000000000000000 RSI: 0000000000000166 RDI: ffffc9000b8e52a0 RBP: 0000000000000166 R08: ffffc9000b8e52b7 R09: 0000000000000000 R10: ffffc9000b8e52a0 R11: fffff5200171ca57 R12: dffffc0000000000 R13: 0000000000000166 R14: ffffc9000b8e5621 R15: 0000000005ffff0a FS: 0000000000000000(0000) GS:ffff888125d83000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c8ca994ed0 CR3: 0000000032be2000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: put_dec_trunc8+0x1e/0x340 lib/vsprintf.c:229 number+0x2f8/0xf60 lib/vsprintf.c:505 vsnprintf+0x91b/0xf00 lib/vsprintf.c:2838 sprintf+0xd9/0x120 lib/vsprintf.c:3037 print_time kernel/printk/printk.c:1381 [inline] info_print_prefix+0x155/0x310 kernel/printk/printk.c:1407 record_print_text+0x154/0x430 kernel/printk/printk.c:1456 printk_get_next_message+0x26d/0x7b0 kernel/printk/printk.c:3024 console_emit_next_record kernel/printk/printk.c:3092 [inline] console_flush_all+0x4ca/0xc40 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xc4/0x270 kernel/printk/printk.c:3325 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450 _printk+0xcf/0x120 kernel/printk/printk.c:2475 __xfs_printk fs/xfs/xfs_message.c:24 [inline] _xfs_alert_tag+0x1cb/0x2d0 fs/xfs/xfs_message.c:74 xfs_buf_verifier_error+0x150/0x2a0 fs/xfs/xfs_error.c:455 xfs_allocbt_read_verify+0x5f/0xe0 fs/xfs/libxfs/xfs_alloc_btree.c:-1 __xfs_buf_ioend+0x342/0x6f0 fs/xfs/xfs_buf.c:1177 xfs_buf_iowait+0x167/0x480 fs/xfs/xfs_buf.c:1384 _xfs_buf_read fs/xfs/xfs_buf.c:646 [inline] xfs_buf_read_map+0x335/0xa50 fs/xfs/xfs_buf.c:712 xfs_trans_read_buf_map+0x1d7/0x8e0 fs/xfs/xfs_trans_buf.c:304 xfs_trans_read_buf fs/xfs/xfs_trans.h:212 [inline] xfs_btree_read_buf_block+0x290/0x470 fs/xfs/libxfs/xfs_btree.c:1402 xfs_btree_lookup_get_block+0x28d/0x500 fs/xfs/libxfs/xfs_btree.c:1907 xfs_btree_lookup+0x4e1/0x1410 fs/xfs/libxfs/xfs_btree.c:2018 xfs_alloc_lookup fs/xfs/libxfs/xfs_alloc.c:166 [inline] xfs_alloc_lookup_eq fs/xfs/libxfs/xfs_alloc.c:184 [inline] xfs_alloc_fixup_trees+0x21b/0xd20 fs/xfs/libxfs/xfs_alloc.c:626 xfs_alloc_cur_finish+0xd3/0x4b0 fs/xfs/libxfs/xfs_alloc.c:1117 xfs_alloc_ag_vextent_near+0xd1a/0x1230 fs/xfs/libxfs/xfs_alloc.c:1776 xfs_alloc_vextent_iterate_ags+0x640/0x940 fs/xfs/libxfs/xfs_alloc.c:3739 xfs_alloc_vextent_start_ag+0x388/0x850 fs/xfs/libxfs/xfs_alloc.c:3814 xfs_bmap_btalloc_best_length fs/xfs/libxfs/xfs_bmap.c:3627 [inline] xfs_bmap_btalloc fs/xfs/libxfs/xfs_bmap.c:3672 [inline] xfs_bmapi_allocate+0x188e/0x2e00 fs/xfs/libxfs/xfs_bmap.c:3947 xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4456 [inline] xfs_bmapi_convert_delalloc+0x7e2/0x1430 fs/xfs/libxfs/xfs_bmap.c:4512 xfs_map_blocks+0x667/0xe80 fs/xfs/xfs_aops.c:405 iomap_writepage_map_blocks fs/iomap/buffered-io.c:1773 [inline] iomap_writepage_map fs/iomap/buffered-io.c:1923 [inline] iomap_writepages+0x10df/0x3240 fs/iomap/buffered-io.c:1977 xfs_vm_writepages+0x235/0x2b0 fs/xfs/xfs_aops.c:650 do_writepages+0x32e/0x550 mm/page-writeback.c:2636 __writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x6b5/0x1000 fs/fs-writeback.c:1976 wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2156 wb_do_writeback fs/fs-writeback.c:2303 [inline] wb_workfn+0x409/0xef0 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245