INFO: task syz.4.1767:21301 blocked for more than 143 seconds. Not tainted 6.13.0-rc3-syzkaller-00193-ge9b8ffafd20a #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1767 state:D stack:26800 pid:21301 tgid:21299 ppid:16653 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0xe7/0x350 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+0x62b/0xa60 kernel/locking/mutex.c:735 expkey_flush+0x18/0x90 fs/nfsd/export.c:261 write_flush.constprop.0+0x2a1/0x3a0 net/sunrpc/cache.c:1544 pde_write fs/proc/inode.c:330 [inline] proc_reg_write+0x23d/0x330 fs/proc/inode.c:342 vfs_write+0x24c/0x1150 fs/read_write.c:677 ksys_write+0x12b/0x250 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0421185d29 RSP: 002b:00007f0421f35038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f0421375fa0 RCX: 00007f0421185d29 RDX: 0000000000000006 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007f0421201aa8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f0421375fa0 R15: 00007ffd706c9b38 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8ddbad40 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8ddbad40 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ddbad40 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6744 3 locks held by kworker/u8:9/3522: #0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12cd/0x1b30 kernel/workqueue.c:3204 #1: ffffc9000c717d80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1b30 kernel/workqueue.c:3205 #2: ffffffff8faa9c50 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xbb/0xbd0 net/core/net_namespace.c:602 2 locks held by getty/5593: #0: ffff8880312170a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5832: #0: ffff88807bd720e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88807bd720e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88807bd720e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:505 #1: ffffffff8e1bb108 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:625 2 locks held by syz.3.1273/15908: #0: ffffffff8fb5e4d0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e1bb108 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xe3/0x1b40 fs/nfsd/nfsctl.c:1964 3 locks held by syz.4.1767/21301: #0: ffff88807cf195f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x267/0x390 fs/file.c:1191 #1: ffff88805cd18420 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:731 #2: ffffffff8e1bb108 (nfsd_mutex){+.+.}-{4:4}, at: expkey_flush+0x18/0x90 fs/nfsd/export.c:261 2 locks held by syz.5.2191/27538: 1 lock held by syz.7.2222/27932: 2 locks held by syz.6.2236/27974: #0: ffff88805e828e08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline] #0: ffff88805e828e08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:639 #1: ffffffff8ddc6678 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:297 1 lock held by syz.2.2238/27979: #0: ffff888077bdc408 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline] #0: ffff888077bdc408 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:639 1 lock held by syz.7.2239/27988: #0: ffffffff8faa9c50 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x292/0x6c0 net/core/net_namespace.c:512 1 lock held by syz.6.2236/27994: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc3-syzkaller-00193-ge9b8ffafd20a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 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+0xf14/0x1240 kernel/hung_task.c:397 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 27538 Comm: syz.5.2191 Not tainted 6.13.0-rc3-syzkaller-00193-ge9b8ffafd20a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:122 [inline] RIP: 0010:lock_is_held_type+0x3d/0x150 kernel/locking/lockdep.c:5914 Code: 53 48 83 ec 08 8b 0d 26 ed 02 05 85 c9 0f 84 dd 00 00 00 65 8b 05 4b 62 e8 74 85 c0 0f 85 ce 00 00 00 65 4c 8b 25 b3 b0 e9 74 <41> 8b 94 24 dc 0a 00 00 85 d2 0f 85 b6 00 00 00 48 89 fd 41 89 f6 RSP: 0018:ffffc9000456f1f8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffffea00020d9ec0 RCX: 0000000000000001 RDX: ffff888027951e00 RSI: 00000000ffffffff RDI: ffff8880282a10d0 RBP: ffffc9000456f358 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000002 R12: ffff888027951e00 R13: 00000000ffffffff R14: ffff8880282a10b8 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9806947ab8 CR3: 0000000078ea6000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] xa_entry include/linux/xarray.h:1220 [inline] xas_descend lib/xarray.c:207 [inline] xas_load+0x385/0x5b0 lib/xarray.c:245 xas_store+0xb1b/0x1960 lib/xarray.c:790 page_cache_delete mm/filemap.c:149 [inline] __filemap_remove_folio+0x368/0x570 mm/filemap.c:232 filemap_remove_folio+0xc8/0x210 mm/filemap.c:264 truncate_inode_folio+0x49/0x70 mm/truncate.c:162 shmem_undo_range+0x36e/0x1170 mm/shmem.c:1036 shmem_truncate_range mm/shmem.c:1152 [inline] shmem_evict_inode+0x3a3/0xba0 mm/shmem.c:1280 evict+0x409/0x960 fs/inode.c:796 iput_final fs/inode.c:1946 [inline] iput fs/inode.c:1972 [inline] iput+0x52a/0x890 fs/inode.c:1958 dentry_unlink_inode+0x29c/0x480 fs/dcache.c:422 __dentry_kill+0x1d0/0x600 fs/dcache.c:625 dput.part.0+0x4b1/0x9b0 fs/dcache.c:867 dput+0x1f/0x30 fs/dcache.c:857 __fput+0x515/0xb60 fs/file_table.c:458 task_work_run+0x14e/0x250 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0xadd/0x2d70 kernel/exit.c:938 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 get_signal+0x2576/0x2610 kernel/signal.c:3017 arch_do_signal_or_restart+0x90/0x7e0 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] irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x401000 Code: Unable to access opcode bytes at 0x400fd6. RSP: 002b:000000000000000a EFLAGS: 00010282 RAX: 0000000000000002 RBX: 00007ff547976080 RCX: 00007ff547785d29 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000020003b46 RBP: 00007ff547801aa8 R08: 0000000000000002 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff547976080 R15: 00007ffedadd6868