INFO: task syz-executor264:4246 blocked for more than 143 seconds. Not tainted 6.1.124-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor264 state:D stack:23880 pid:4246 ppid:4244 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 wb_wait_for_completion+0x162/0x290 fs/fs-writeback.c:191 __writeback_inodes_sb_nr+0x2ce/0x370 fs/fs-writeback.c:2653 sync_filesystem+0xa0/0x220 fs/sync.c:54 generic_shutdown_super+0x6b/0x340 fs/super.c:474 kill_block_super+0x7a/0xe0 fs/super.c:1470 deactivate_locked_super+0xa0/0x110 fs/super.c:332 cleanup_mnt+0x490/0x520 fs/namespace.c:1186 task_work_run+0x246/0x300 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7feb9dc6a447 RSP: 002b:00007ffcfe8ecaa8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007feb9dc6a447 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcfe8ecb60 RBP: 00007ffcfe8ecb60 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000202 R12: 00007ffcfe8edbd0 R13: 00005555767ea6c0 R14: 431bde82d7b634db R15: 00007ffcfe8edbf0 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d32b290 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d32ba90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510 2 locks held by kworker/u4:2/32: 2 locks held by getty/4006: #0: ffff8880313d7098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198 1 lock held by syz-executor264/4246: #0: ffff888074b2c0e0 (&type->s_umount_key#42){+.+.}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 6.1.124-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1ae/0x3f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf88/0xfd0 kernel/hung_task.c:377 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 32 Comm: kworker/u4:2 Not tainted 6.1.124-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:xas_load+0x1/0x140 lib/xarray.c:234 Code: 8b 4c 24 28 80 e1 07 38 c1 0f 8c 39 fc ff ff be 08 00 00 00 48 8b 7c 24 28 e8 7b 76 33 f7 e9 25 fc ff ff cc cc cc cc cc cc 55 <41> 57 41 56 41 55 41 54 53 48 83 ec 18 48 89 fb 49 be 00 00 00 00 RSP: 0018:ffffc90000a97010 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 1ffff92000152e13 RCX: ffff88801ca50000 RDX: 0000000000000000 RSI: ffffffff8b5e6820 RDI: ffffc90000a97080 RBP: ffffc90000a97140 R08: ffffffff81b7eb05 R09: fffffbfff2249c4d R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888140c89300 R13: 0000000000000001 R14: ffff888140c892f8 R15: 000000000000007f FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b03ef00600 CR3: 0000000021512000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mapping_get_entry mm/filemap.c:1881 [inline] __filemap_get_folio+0x22c/0xe80 mm/filemap.c:1943 pagecache_get_page+0x28/0x250 mm/folio-compat.c:110 find_get_page_flags include/linux/pagemap.h:602 [inline] __find_get_block_slow fs/buffer.c:202 [inline] __find_get_block+0x3d8/0x1120 fs/buffer.c:1307 __getblk_slow fs/buffer.c:1034 [inline] __getblk_gfp+0x146/0xa20 fs/buffer.c:1333 __bread_gfp+0x2a/0x370 fs/buffer.c:1367 sb_bread include/linux/buffer_head.h:338 [inline] __fat_write_inode+0x281/0x9d0 fs/fat/inode.c:870 write_inode fs/fs-writeback.c:1460 [inline] __writeback_single_inode+0x67d/0x11e0 fs/fs-writeback.c:1677 writeback_sb_inodes+0xc2b/0x1b20 fs/fs-writeback.c:1903 wb_writeback+0x49d/0xe10 fs/fs-writeback.c:2077 wb_do_writeback fs/fs-writeback.c:2220 [inline] wb_workfn+0x427/0x1020 fs/fs-writeback.c:2260 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.634 msecs