INFO: task syz-executor:6221 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21192 pid:6221 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 wb_wait_for_completion+0x166/0x290 fs/fs-writeback.c:192 sync_inodes_sb+0x1bc/0x9e0 fs/fs-writeback.c:2772 sync_filesystem+0x171/0x220 fs/sync.c:64 generic_shutdown_super+0x6f/0x2b0 fs/super.c:666 kill_block_super+0x44/0x90 fs/super.c:1660 xfs_kill_sb+0x15/0x50 fs/xfs/xfs_super.c:2041 deactivate_locked_super+0x97/0x100 fs/super.c:481 cleanup_mnt+0x429/0x4c0 fs/namespace.c:1259 task_work_run+0x1ce/0x250 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f231b390a77 RSP: 002b:00007ffc27ff2848 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f231b413d7d RCX: 00007f231b390a77 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc27ff2900 RBP: 00007ffc27ff2900 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc27ff3990 R13: 00007f231b413d7d R14: 0000000000018b0f R15: 00007ffc27ff39d0 Showing all locks held in the system: 4 locks held by kworker/u4:0/11: #0: ffff888142278d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888142278d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90000107d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0} , at: process_one_work kernel/workqueue.c:2609 [inline] , at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff88807b676608 (sb_internal#2){.+.+}-{0:0}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4534 [inline] #2: ffff88807b676608 (sb_internal#2){.+.+}-{0:0}, at: xfs_bmapi_convert_delalloc+0x2f4/0x1490 fs/xfs/libxfs/xfs_bmap.c:4661 #3: ffff88805fda46d8 (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4539 [inline] #3: ffff88805fda46d8 (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_bmapi_convert_delalloc+0x320/0x1490 fs/xfs/libxfs/xfs_bmap.c:4661 1 lock held by khungtaskd/29: #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 4 locks held by kworker/u4:4/59: #0: ffff888142278d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888142278d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900015a7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] ffffc900015a7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff888023c80608 ( sb_internal #2 ){.+.+}-{0:0} , at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4534 [inline] , at: xfs_bmapi_convert_delalloc+0x2f4/0x1490 fs/xfs/libxfs/xfs_bmap.c:4661 #3: ffff88805fdd9098 (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4539 [inline] (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_bmapi_convert_delalloc+0x320/0x1490 fs/xfs/libxfs/xfs_bmap.c:4661 4 locks held by kworker/u4:5/1003: 4 locks held by kworker/u4:7/1133: #0: ffff888142278d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc9000473fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000473fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff888060ede608 (sb_internal#2){.+.+}-{0:0}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4534 [inline] #2: ffff888060ede608 (sb_internal#2){.+.+}-{0:0}, at: xfs_bmapi_convert_delalloc+0x2f4/0x1490 fs/xfs/libxfs/xfs_bmap.c:4661 #3: ffff8880742b3758 ( &xfs_nondir_ilock_class #3 ){++++}-{3:3} , at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4539 [inline] , at: xfs_bmapi_convert_delalloc+0x320/0x1490 fs/xfs/libxfs/xfs_bmap.c:4661 2 locks held by getty/5525: #0: ffff88802cb380a0 ( &tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 2 locks held by syz-executor/6221: #0: ffff888023c800e0 ( &type->s_umount_key #56 ){++++}-{3:3} , at: __super_lock fs/super.c:56 [inline] , at: __super_lock_excl fs/super.c:71 [inline] , at: deactivate_super+0xa4/0xe0 fs/super.c:513 #1: ffff888140fa27d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a0/0x9e0 fs/fs-writeback.c:2770 2 locks held by syz-executor/6856: #0: ffff88802cf8c0e0 ( &type->s_umount_key #56 ){++++}-{3:3} , at: __super_lock fs/super.c:56 [inline] , at: __super_lock_excl fs/super.c:71 [inline] , at: deactivate_super+0xa4/0xe0 fs/super.c:513 #1: ffff888140ff07d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] #1: ffff888140ff07d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a0/0x9e0 fs/fs-writeback.c:2770 2 locks held by kworker/1:7/7175: 2 locks held by syz-executor/7433: #0: ffff888060ede0e0 (&type->s_umount_key#56){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff888060ede0e0 (&type->s_umount_key#56){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff888060ede0e0 (&type->s_umount_key#56){++++}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513 #1: ffff8881482bc7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] #1: ffff8881482bc7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a0/0x9e0 fs/fs-writeback.c:2770 2 locks held by syz-executor/7945: #0: ffff88807b6760e0 (&type->s_umount_key#56){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88807b6760e0 (&type->s_umount_key#56){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88807b6760e0 (&type->s_umount_key#56){++++}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513 #1: ffff888140f887d0 (&bdi->wb_switch_rwsem ){+.+.}-{3:3} , at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] , at: sync_inodes_sb+0x1a0/0x9e0 fs/fs-writeback.c:2770 1 lock held by rm/8208: #0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5951 Comm: kworker/1:5 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: xfs-buf/loop8 xfs_buf_ioend_work RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:60 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:127 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:178 [inline] RIP: 0010:kasan_check_range+0x41/0x290 mm/kasan/generic.c:187 Code: 54 53 4c 8d 04 37 49 39 f8 0f 82 5a 02 00 00 49 89 f9 49 c1 e9 2f 41 81 f9 ff ff 01 00 0f 82 46 02 00 00 49 89 ff 49 c1 ef 03 <49> ba 00 00 00 00 00 fc ff df 4f 8d 1c 17 49 ff c8 4d 89 c1 49 c1 RSP: 0018:ffffc900034c72a8 EFLAGS: 00000a06 RAX: 0000000000000001 RBX: 0000000000000058 RCX: ffffffff816aab8b RDX: 0000000000000001 RSI: 0000000000000058 RDI: ffffc900034c73c0 RBP: 0000000000000000 R08: ffffc900034c7418 R09: 000000000001ffff R10: 0000000000000000 R11: 0000000000000000 R12: ffffc900034c73c0 R13: 1ffff92000698e6c R14: ffffc900034c73c0 R15: 1ffff92000698e78 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffee08d9c24 CR3: 000000002edb6000 CR4: 00000000003506e0 Call Trace: __asan_memset+0x22/0x40 mm/kasan/shadow.c:84 printk_get_next_message+0xfb/0x8e0 kernel/printk/printk.c:2834 console_emit_next_record kernel/printk/printk.c:2911 [inline] console_flush_all+0x3ad/0xd00 kernel/printk/printk.c:3000 console_unlock+0xae/0x340 kernel/printk/printk.c:3069 vprintk_emit+0x477/0x600 kernel/printk/printk.c:2341 _printk+0xd0/0x110 kernel/printk/printk.c:2366 print_hex_dump+0x1a9/0x260 lib/hexdump.c:285 xfs_hex_dump+0x3d/0x50 fs/xfs/xfs_message.c:110 xfs_buf_verifier_error+0x1cc/0x2a0 fs/xfs/xfs_error.c:460 xfs_allocbt_read_verify+0x5f/0xd0 fs/xfs/libxfs/xfs_alloc_btree.c:-1 xfs_buf_ioend+0x260/0x6f0 fs/xfs/xfs_buf.c:1309 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293