INFO: task syz.6.2129:13817 blocked for more than 143 seconds. Not tainted 6.13.0-syzkaller-00164-g100ceb4817a2 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.2129 state:D stack:23544 pid:13817 tgid:13816 ppid:7393 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905 __mutex_lock_common kernel/locking/mutex.c:665 [inline] __mutex_lock+0x7e7/0xee0 kernel/locking/mutex.c:735 netfs_writepages+0x12b/0x9e0 fs/netfs/write_issue.c:564 do_writepages+0x35f/0x880 mm/page-writeback.c:2708 filemap_fdatawrite_wbc mm/filemap.c:388 [inline] __filemap_fdatawrite_range mm/filemap.c:421 [inline] __filemap_fdatawrite mm/filemap.c:427 [inline] filemap_fdatawrite+0x1f3/0x2a0 mm/filemap.c:432 v9fs_dir_release+0x151/0x560 fs/9p/vfs_dir.c:219 __fput+0x23c/0xa50 fs/file_table.c:450 task_work_run+0x24f/0x310 kernel/task_work.c:239 get_signal+0x15f7/0x1750 kernel/signal.c:2809 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7c67785d29 RSP: 002b:00007f7c655f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: 00000000000d0000 RBX: 00007f7c67975fa0 RCX: 00007f7c67785d29 RDX: 0000000000000000 RSI: 000000000000000a RDI: 0000000000000009 RBP: 00007f7c67801b08 R08: 0000000000000000 R09: 0000000000000000 R10: 000000007ffff000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f7c67975fa0 R15: 00007ffeb63fde88 Showing all locks held in the system: 1 lock held by rcu_exp_gp_kthr/19: 1 lock held by khungtaskd/30: #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6744 2 locks held by kworker/u8:6/2978: 2 locks held by getty/5573: #0: ffff8880361c20a0 (&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+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 3 locks held by kworker/u8:3/12204: #0: ffff88802068a148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88802068a148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc900050efd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc900050efd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 #2: ffff88807ce38b70 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0x12b/0x9e0 fs/netfs/write_issue.c:564 2 locks held by kworker/u8:9/12206: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc90005127d00 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90005127d00 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 1 lock held by syz.6.2129/13817: #0: ffff88807ce38b70 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0x12b/0x9e0 fs/netfs/write_issue.c:564 3 locks held by syz.6.2129/13822: #0: ffff888053684420 (sb_writers#25){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:547 #1: ffff88807ce387b8 (&sb->s_type->i_mutex_key#31){++++}-{4:4}, at: inode_lock include/linux/fs.h:831 [inline] #1: ffff88807ce387b8 (&sb->s_type->i_mutex_key#31){++++}-{4:4}, at: vfs_utimes+0x44d/0x770 fs/utimes.c:65 #2: ffff88807ce38b70 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xcf/0x9e0 fs/netfs/write_issue.c:558 2 locks held by syz.8.2236/14239: #0: ffff8880536840e0 (&type->s_umount_key#74){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880536840e0 (&type->s_umount_key#74){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff8880536867d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8880536867d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-syzkaller-00164-g100ceb4817a2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:234 [inline] watchdog+0xff6/0x1040 kernel/hung_task.c:397 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5808 Comm: syz-executor Not tainted 6.13.0-syzkaller-00164-g100ceb4817a2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:__fget_light fs/file.c:1148 [inline] RIP: 0010:fdget fs/file.c:1160 [inline] RIP: 0010:fdget_pos+0x102/0x320 fs/file.c:1187 Code: 03 4c 03 3b 4c 89 f8 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 ff e8 9e da e5 ff 49 8b 1f 4c 89 f6 48 21 de 31 ff e8 4e ff 81 ff <49> 21 de 0f 84 91 00 00 00 e8 60 fa 81 ff 4c 89 f7 48 83 c7 48 48 RSP: 0018:ffffc90003c4fe10 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880275b4a80 RCX: ffff88802f940000 RDX: ffff88802f940000 RSI: ffff8880275b4a80 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffffffff821d7a42 R09: 1ffff110068739e0 R10: dffffc0000000000 R11: ffffed10068739e1 R12: dffffc0000000000 R13: 00007ffd74bac2cc R14: ffffffffffffffff R15: ffff888035820018 FS: 000055557d79a500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055557a0bc5c8 CR3: 000000006dd96000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: class_fd_pos_constructor include/linux/file.h:85 [inline] ksys_read+0x7c/0x2b0 fs/read_write.c:699 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f053f9846fd Code: a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb b5 e8 a8 48 00 00 0f 1f 84 00 00 00 00 00 80 3d 41 7e 1c 00 00 74 17 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 5b c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec RSP: 002b:00007ffd74bac2b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f053f9846fd RDX: 0000000000000004 RSI: 00007ffd74bac2cc RDI: 0000000000000003 RBP: 0000000000000000 R08: 00000000275de526 R09: 7fffffffffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd74bac6e0 R13: 0000000000000004 R14: 00007ffd74bac2cc R15: 00007ffd74bac360